| 1. |
- Brooke, Robert, 1989-, et al.
(författare)
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Greyscale and paper electrochromic polymer displays by UV patterning
- 2019
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Ingår i: Polymers. - : MDPI AG. - 2073-4360. ; 11:2
-
Tidskriftsartikel (refereegranskat)abstract
- Electrochromic devices have important implications as smart windows for energy efficient buildings, internet of things devices, and in low-cost advertising applications. While inorganics have so far dominated the market, organic conductive polymers possess certain advantages such as high throughput and low temperature processing, faster switching, and superior optical memory. Here, we present organic electrochromic devices that can switch between two high-resolution images, based on UV-patterning and vapor phase polymerization of poly(3,4- ethylenedioxythiophene) films. We demonstrate that this technique can provide switchable greyscale images through the spatial control of a UV-light dose. The color space was able to be further altered via optimization of the oxidant concentration. Finally, we utilized a UV-patterning technique to produce functional paper with electrochromic patterns deposited on porous paper, allowing for environmentally friendly electrochromic displays.
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| 2. |
- Che, Canyan, 1988-, et al.
(författare)
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Twinning Lignosulfonate with a Conducting Polymer via Counter-Ion Exchange for Large-Scale Electrical Storage
- 2019
-
Ingår i: Advanced Sustainable Systems. - : Wiley-VCH Verlag. - 2366-7486. ; 3:9
-
Tidskriftsartikel (refereegranskat)abstract
- Lignosulfonate (LS) is a large-scale surplus product of the forest and paper industries, and has primarily been utilized as a low-cost plasticizer in making concrete for the construction industry. LS is an anionic redox-active polyelectrolyte and is a promising candidate to boost the charge capacity of the positive electrode (positrode) in redox-supercapacitors. Here, the physical-chemical investigation of how this biopolymer incorporates into the conducting polymer PEDOT matrix, of the positrode, by means of counter-ion exchange is reported. Upon successful incorporation, an optimal access to redox moieties is achieved, which provides a 63% increase of the resulting stored electrical charge by reversible redox interconversion. The effects of pH, ionic strength, and concentrations, of included components, on the polymer–polymer interactions are optimized to exploit the biopolymer-associated redox currents. Further, the explored LS-conducting polymer incorporation strategy, via aqueous synthesis, is evaluated in an up-scaling effort toward large-scale electrical energy storage technology. By using an up-scaled production protocol, integration of the biopolymer within the conducting polymer matrix by counter-ion exchange is confirmed and the PEDOT-LS synthesized through optimized strategy reaches an improved charge capacity of 44.6 mAh g−1.
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| 3. |
- Chen, Shangzhi, et al.
(författare)
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Redox-tunable structural colour images by UV-patterned conducting polymer nanofilms on metal surfaces
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Precise manipulation of light-matter interaction has enabled a wide variety of approaches to create bright and vivid structural colours. Techniques utilizing photonic crystals, Fabry-Pérot cavities, plasmonics, or high-refractive index dielectric metasurfaces have been studied for applications ranging from optical coatings to reflective displays. However, complicated fabrication procedures for sub-wavelength nanostructures, limited active areas, and inherent absence of tunability of these approaches significantly impede their further development towards flexible, large-scale, and switchable devices compatible with facile and cost-effective production. Herein, we present a simple and efficient method to generate structural colours based on nanoscale conducting polymer films prepared on metallic surfaces via vapour phase polymerization and ultraviolet (UV) light patterning. Varying the UV dose enables synergistic control of both nanoscale film thickness and polymer permittivity, which generates controllable colours from violet to red. Together with greyscale photomasks this enables fabrication of high-resolution colour images using single exposure steps. We further demonstrate spatiotemporal tuning of the structurally coloured surfaces and images via electrochemical modulation of the polymer redox state. The simple structure, facile fabrication, wide colour gamut, and dynamic colour tuning make this concept competitive for future multi-functional and smart displays.
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| 4. |
- Kim, Nara, 1985-, et al.
(författare)
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Electric transport properties in PEDOT thin films
- 2019. - 4
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Ingår i: Conjugated polymers. - Boca Raton : CRC Press. - 9780429190520 ; , s. 45-128
-
Bokkapitel (refereegranskat)abstract
- In this chapter, the authors summarize their understanding of Poly(3,4-ethylenedioxythiophene) (PEDOT), with respect to its chemical and physical fundamentals. They focus upon the structure of several PEDOT systems, from the angstrom level and up, and the impact on both electronic and ionic transport. The authors discuss the structural properties of PEDOT:X and PEDOT:poly(styrenesulfonate) based on experimental data probed at the scale ranging from angstrom to submicrometer. The morphology of PEDOT is influenced by the nature of counter-ions, especially at high oxidation levels. The doping anions intercalate between PEDOT chains to form a “sandwich” structure to screen the positive charges in PEDOT chains. The authors provide the main transport coefficients such as electrical conductivity s, Seebeck coefficient S, and Peltier coefficient σ, starting from a general thermodynamic consideration. The optical conductivity of PEDOT has also been examined based on the effective medium approximation, which is normally used to describe microscopic permittivity properties of composites made from several different constituents.
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| 5. |
- Mitraka, Evangelia, 1986-
(författare)
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Conducting Polymer Electrodes for Oxygen Reduction Reaction
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Both the pollution level of the environment and the increasing energy demands have stimulated intense research on the development of low-cost environmentally-friendly energy conversion and storage systems with high efficiency, such as metal-air batteries and fuel cells.One of the most essential parts of both fuel cells and metal–air batteries is the air-electrode which is responsible for the reduction of O2. The air-electrode can use O2 from air facilitating the layout of the device; however, the process taking place on it is significantly complex. Currently, platinum (Pt) is the benchmark for air-electrodes in such technologies, although it is expensive and exhibits other important disadvantages which diminish the fuel cell performance. Therefore, extensive research has been devoted to reduce the amount of Pt used in air-electrodes and to develop a noble metal-free version of these electrodes.The area of printed electronics could facilitate the development of low-cost electrodes produced in high volume for such applications. Conducting polymers are attractive materials for this technology because they may combine several desired properties, like electronic conduction, ionic conduction and catalysis of electrochemical reactions.Among other conducting polymers, poly(3,4-ethylenedioxythiophene) (PEDOT) emerged as an alternative cathode catalyst material to Pt, due to its ability to effectively catalyze the oxygen reduction reaction (ORR), while it also exhibits high electrical and ionic conductivity.The focus of this thesis is to study the electrocatalytic activity and mechanism of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) when employed as an airelectrode in energy storage devices, such as fuel cells and metal-air batteries. Although PEDOT is extensively studied during the last decade as an air-electrode for fuel cell and metal-air batteries, vital pieces of the catalytic mechanism that PEDOT follows remain unknown, namely: (i) the sites of PEDOT on which O2 interacts and (ii) the intermediate species which are formed during the ORR. The content of this thesis tackles these topics, both from experimental and theoretical point of view. Moreover, it investigates the use of PEDOT as an active electrocatalyst in a polymer exchange membrane (PEM) fuel cell, by embedding the polymer in a cellulose matrix, aiming to fabricate a gas diffusion electrode for the ORR side of the device. Finally, the goal of the thesis surpasses the limit of the p-doped PEDOT and undertakes the evaluation of a n-type conjugated polymer of high electron affinity as a cathode in reduction processes.
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| 6. |
- Shiran Chaharsoughi, Mina, 1986-, et al.
(författare)
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Hybrid Plasmonic and Pyroelectric Harvesting of Light Fluctuations
- 2018
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Ingår i: Advanced Optical Materials. - : Wiley-Blackwell. - 2162-7568 .- 2195-1071.
-
Tidskriftsartikel (refereegranskat)abstract
- State-of-the-art solar energy harvesting systems based on photovoltaic technology require constant illumination for optimal operation. However, weather conditions and solar illumination tend to fluctuate. Here, a device is presented that extracts electrical energy from such light fluctuations. The concept combines light-induced heating of gold nanodisks (acting as plasmonic optical nanoantennas), and an organic pyroelectric copolymer film (poly(vinylidenefluoride-co-trifluoroethylene)), that converts temperature changes into electrical signals. This hybrid device can repeatedly generate current pulses, not only upon the onset of illumination, but also when illumination is blocked. Detailed characterization highlights the key role of the polarization state of the copolymer, while the copolymer thickness has minor influence on performance. The results are fully consistent with plasmon-assisted pyroelectric effects, as corroborated by combined optical and thermal simulations that match the experimental results. Owing to the tunability of plasmonic resonances, the presented concept is compatible with harvesting near infrared light while concurrently maintaining visible transparency.
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| 7. |
- Wu, Zhixing, 1990-, et al.
(författare)
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Conducting Polymer‐Based e‐Refinery for Sustainable Hydrogen Peroxide Production
- 2023
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Ingår i: Energy & Environmental Materials. - : Wiley-Blackwell. - 2575-0356.
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Tidskriftsartikel (refereegranskat)abstract
- Electrocatalysis enables the industrial transition to sustainable production of chemicals using abundant precursors and electricity from renewable sources. De-centralized production of hydrogen peroxide (H2O2) from water and oxygen of air is highly desirable for daily life and industry. We report an effective electrochemical refinery (e-refinery) for H2O2 by means of electrocatalysis-controlled comproportionation reaction (2(H)O + O -> 2(HO)), feeding pure water and oxygen only. Mesoporous nickel (II) oxide (NiO) was used as electrocatalyst for oxygen evolution reaction (OER), producing oxygen at the anode. Conducting polymer poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS) drove the oxygen reduction reaction (ORR), forming H2O2 on the cathode. The reactions were evaluated in both half-cell and device configurations. The performance of the H2O2 e-refinery, assembled on anion-exchange solid electrolyte and fed with pure water, was limited by the unbalanced ionic transport. Optimization of the operation conditions allowed a conversion efficiency of 80%.
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| 8. |
- Abrahamsson, Tobias, 1991-
(författare)
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Synthetic Functionalities for Ion and Electron Conductive Polymers : Applications in Organic Electronics and Biological Interfaces
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the search for understanding and communicating with all biological systems, in humans, animals, plants, and even microorganisms, we find a common language of all communicating via electrons, ions and molecules. Since the discovery of organic electronics, the ability to bridge the gap and communicate be-tween modern technology and biology has emerged. Organic chemistry pro-vides us with tools for understanding and a material platform of polymer electronics for communication. Such insights give us not only the ability to observe fundamental phenomenon but to actively design and construct materials with chemical functionalities towards better interfaces and applications. Organic electronic materials and devices have found their way to be implemented in the field of medicine for diagnostic and therapeutic purposes, but also in water purification and to help tackle the monumental task in creating the next generation of sustainable energy production and storage. Ultimately it’s safe to say that organic electronics are not going to replace our traditional technology based on inorganic materials but rather the two fields can find a way to complement each other for various purposes and applications. Compared to conventional silicon based technology, production of carbon-based organic electronic polymer materials are extremely cheap and devices can even be made flexible and soft with great compatibility towards biology. The main focus of this thesis has been developing and synthesizing new types of organic electronic and ionic conductive polymeric materials. Rational chemical design and modifications of the materials have been utilized to introduce specific functionalities to the materials. The functionalities serving the purpose to facilitate ion and electron conductive charge transport for organic electronics and with biological interface implementation of the polymer materials. Multi-functional ionic conductive hyperbranched polyglycerol polyelectrolytes (dendrolytes) were developed comprising both ionically charged groups and cross-linkable groups. The hyperbranched polyglycerol core structure of the material possesses a hydrophilic solvating platform for both ions and maintenance of solvent molecules, while being a biocompatible structure. Coupled with the peripheral charged ionic functionalities of the polymer, the dendrolyte materials are highly ionic conductive and selective towards cationic and anionic charged atoms and large molecules when implemented as ion-exchange membranes. Homogenous ion-exchange membrane casting has been achieved by the implementation of cross-linkable functionalities in the dendrolytes, utilizing robust click-chemistry for efficient micro and macro fabrication processing of the ion-ex-change membranes for organic electronic devices. The ion-exchange membrane material was implemented in electrophoretic drug delivery devices (organic electronic ion pumps), which are used for delivery of ions and neurotransmitters with spatiotemporal resolution and are able to communicate and be used for therapeutic drug delivery purposes in biological interfaces. The dendrolyte materials were also able to form free-standing membranes, making it possible for implementation in fuel cell and desalination purposes. Trimeric conjugated thiophene pre-polymer structures were also developed in the thesis and synthesized for the purpose of implementation of the material in vivo to form electrically conductive polymer structures, and in such manner to be able to create electrodes and ultimately to connect with the central nervous system. The conjugated pre-polymers being both water soluble and enzymatically polymerizable serve as a platform to realize such a concept. Also, modifying the trimeric structure with cross-linkable functionality created the capability to form better interfaces and stability towards biological environments.
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| 9. |
- Ahmed, Fareed, et al.
(författare)
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Manufacturing Poly(3,4-Ethylenedioxythiophene) Electrocatalytic Sheets for Large-Scale H2O2 Production
- 2022
-
Ingår i: Advanced Sustainable Systems. - : John Wiley and Sons Inc. - 2366-7486. ; 6:1
-
Tidskriftsartikel (refereegranskat)abstract
- Producing thick films of conducting polymers by a low-cost manufacturing technique would enable new applications. However, removing huge solvent volume from diluted suspension or dispersion (1–3 wt%) in which conducting polymers are typically obtained is a true manufacturing challenge. In this work, a procedure is proposed to quickly remove water from the conducting polymer poly(3,4-ethylenedioxythiophene:poly(4-styrene sulfonate) (PEDOT:PSS) suspension. The PEDOT:PSS suspension is first flocculated with 1 m H2SO4 transforming PEDOT nanoparticles (≈50–500 nm) into soft microparticles. A filtration process inspired by pulp dewatering in a paper machine on a wire mesh with apertures dimension between 60 µm and 0.5 mm leads to thick free-standing films (≈0.5 mm). Wire mesh clogging that hinders dewatering (known as dead-end filtration) is overcome by adding to the flocculated PEDOT:PSS dispersion carbon fibers that aggregate and form efficient water channels. Moreover, this enables fast formation of thick layers under simple atmospheric pressure filtration, thus making the process truly scalable. Thick freestanding PEDOT films thus obtained are used as electrocatalysts for efficient reduction of oxygen to hydrogen peroxide, a promising green chemical and fuel. The inhomogeneity of the films does not affect their electrochemical function. © 2021 The Authors.
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| 10. |
- Ail, Ujwala, 1980-, et al.
(författare)
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Optimization of Non-Pyrolyzed Lignin Electrodes for Sustainable Batteries
- 2023
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Ingår i: ADVANCED SUSTAINABLE SYSTEMS. - : WILEY-V C H VERLAG GMBH. - 2366-7486. ; 7:2
-
Tidskriftsartikel (refereegranskat)abstract
- Lignin, a byproduct from the pulp industry, is one of the redox active biopolymers being investigated as a component in the electrodes for sustainable energy storage applications. Due to its insulating nature, it needs to be combined with a conductor such as carbon or conducting polymer for efficient charge storage. Here, the lignin/carbon composite electrodes manufactured via mechanical milling (ball milling) are reported. The composite formation, correlation between performance and morphology is studied by comparison with manual mixing and jet milling. Superior charge storage capacity with approximate to 70% of the total contribution from the Faradaic process involving the redox functionality of lignin is observed in a mechanically milled composite. In comparison, manual mix shows only approximate to 30% from the lignin storage participation while the rest is due to the electric double layer at the carbon-electrolyte interface. The significant participation of lignin in the ball milled composite is attributed to the homogeneous, intimate mixing of the carbon and the lignin leading the electronic carrier transported in the carbon phase to reach most of the redox group of lignin. A maximum capacity of 49 mAh g(-1) is obtained at charge/discharge rate of 0.25 A g(-1) for the sample milled for 60 min.
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| 11. |
- Ajjan, Fátima, 1986-, et al.
(författare)
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Doped Conjugated Polymer Enclosing a Redox Polymer : Wiring Polyquinones with Poly(3,4‐Ethylenedioxythiophene)
- 2020
-
Ingår i: Advanced Energy and Sustainability Research. - : John Wiley & Sons. - 2699-9412. ; 1:2
-
Tidskriftsartikel (refereegranskat)abstract
- The mass implementation of renewable energies is limited by the absence of efficient and affordable technology to store electrical energy. Thus, the development of new materials is needed to improve the performance of actual devices such as batteries or supercapacitors. Herein, the facile consecutive chemically oxidative polymerization of poly(1-amino-5-chloroanthraquinone) (PACA) and poly(3,4-ethylenedioxythiophene (PEDOT) resulting in a water dispersible material PACA-PEDOT is shown. The water-based slurry made of PACA-PEDOT nanoparticles can be processed as film coated in ambient atmosphere, a critical feature for scaling up the electrode manufacturing. The novel redox polymer electrode is a nanocomposite that withstands rapid charging (16 A g−1) and delivers high power (5000 W kg−1). At lower current density its storage capacity is high (198 mAh g−1) and displays improved cycling stability (60% after 5000 cycles). Its great electrochemical performance results from the combination of the redox reversibility of the quinone groups in PACA that allows a high amount of charge storage via Faradaic reactions and the high electronic conductivity of PEDOT to access to the redox-active sites. These promising results demonstrate the potential of PACA-PEDOT to make easily organic electrodes from a water-coating process, without toxic metals, and operating in non-flammable aqueous electrolyte for large scale pseudocapacitors.
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| 12. |
- Andersson Ersman, Peter, et al.
(författare)
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Screen printed digital circuits based on vertical organicelectrochemical transistors
- 2017
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Ingår i: Flexible and Printed Electronics. - : IOP Publishing. - 2058-8585. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Vertical organic electrochemical transistors (OECTs) have been manufactured solely using screenprinting. The OECTs are based on PEDOT:PSS (poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonic acid)), which defines the active material for both the transistor channel and the gateelectrode. The resulting vertical OECT devices and circuits exhibit low-voltage operation, relativelyfast switching, small footprint and high manufacturing yield; the last three parameters are explainedby the reliance of the transistor configuration on a robust structure in which the electrolyte verticallybridges the bottom channel and the top gate electrode. Two different architectures of the verticalOECT have been manufactured, characterized and evaluated in parallel throughout this report. Inaddition to the experimental work, SPICE models enabling simulations of standalone OECTs andOECT-based circuits have been developed. Our findings may pave the way for fully integrated, lowvoltageoperating and printed signal processing systems integrated with e.g. printed batteries, solarcells, sensors and communication interfaces. Such technology can then serve a low-cost basetechnology for the internet of things, smart packaging and home diagnostics applications.
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| 13. |
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| 14. |
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| 15. |
- Arbring Sjöström, Theresia, 1987-, et al.
(författare)
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Design and Operation of Hybrid Microfluidic Iontronic Probes for Regulated Drug Delivery
- 2021
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Ingår i: Advanced Materials Technologies. - Hoboken, New Jersey : John Wiley & Sons. - 2365-709X. ; 6:2
-
Tidskriftsartikel (refereegranskat)abstract
- Highly controlled drug delivery devices play an increasingly important role in the development of new neuroengineering tools. Stringent - and sometimes contradicting - demands are placed on such devices, ranging from robustness in freestanding devices, to overall device miniaturization, while maintaining precise spatiotemporal control of delivery with high chemical specificity and high on/off ratio. Here, design principles of a hybrid microfluidic iontronic probe that uses flow for long-range pressure-driven transport in combination with an iontronic tip that provides electronically fine-tuned pressure-free delivery are explored. Employing a computational model, the effects of decoupling the drug reservoir by exchanging a large passive reservoir with a smaller microfluidic system are reported. The transition at the microfluidic-iontronic interface is found to require an expanded ion exchange membrane inlet in combination with a constant fluidic flow, to allow a broad range of device operation, including low source concentrations and high delivery currents. Complementary to these findings, the free-standing hybrid probe monitored in real time by an external sensor is demonstrated. From these computational and experimental results, key design principles for iontronic devices are outlined that seek to use the efficient transport enabled by microfluidics, and further, key observations of hybrid microfluidic iontronic probes are explained.
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| 16. |
- Arbring Sjöström, Theresia, 1987-
(författare)
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Organic Bioelectronics for Neurotransmitter Release at the Speed of Life
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The signaling dynamics in neuronal networks includes processes ranging from lifelong neuromodulation to direct synaptic neurotransmission. In chemical synapses, the time delay it takes to pass a signal from one neuron to the next lasts for less than a millisecond. At the post-synaptic neuron, further signaling is either up- or down-regulated, dependent on the specific neurotransmitter and receptor. While this up- and down-regulation of signals usually runs perfectly well and enables complex performance, even a minor dysfunction of this signaling system can cause major complications, in the shape of neurological disorders. The field of organic bioelectronics has the ability to interface neurons with high spatiotemporal recording and stimulation techniques. Local chemical stimulation, i.e. local release of neurotransmitters, enables the possibility of artificially altering the chemical environment in dysfunctional signaling pathways to regain or restore neural function. To successfully interface the biological nervous system with electronics, a range of demands must be met. Organic bioelectronic techniques and materials are capable of reaching the demands on the biological as well as the electronic side of the interface. These demands span from high performance biocompatible materials, to miniaturized and specific device architectures, and high dose control on demand within milliseconds.The content of this thesis is a continuation of the development of organic bioelectronic devices for neurotransmitter delivery. Organic materials are utilized to electrically control the dose of charged neurotransmitters by translating electric charge into controlled artificial release. The first part of the thesis, Papers 1 and 2, includes further development of the resistor-type release device called the organic electronic ion pump. This part includes material evaluation, microfluidic incorporation, and device design considerations. The aim for the second part of this thesis, Papers 3 and 4, is to enhance temporal performance, i.e. reduce the delay between electrical signal and neurotransmitter delivery to corresponding delay in biological neural signaling, while retaining tight dosage control. Diffusion of neurotransmitters between nerve cells is a slow process, but since it is restricted to short distances, the total time delay is short. In our organic bioelectronic devices, several orders of magnitude in speed can be gained by switching from lateral to vertical delivery geometries. This is realized by two different types of vertical diodes combined with a lateral preload and waste configuration. The vertical diode assembly was further expanded with a control electrode that enables individual addressing in each of several combined release sites. These integrated circuits allow for release of neurotransmitters with high on/off release ratios, approaching delivery times on par with biological neurotransmission.
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| 17. |
- Berggren, Magnus, 1968-, et al.
(författare)
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Commentary: Organic materials for printed electronics : Editorial in Nature Materials, vol 6, pp 3-5
- 2007
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Ingår i: Nature Materials. - : Nature Publishing Group. - 1476-1122 .- 1476-4660. ; 6, s. 3-5
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Organic materials can offer a low-cost alternative for printed electronics and flexible displays. However, research in these systems must exploit the differences - via molecular-level control of functionality - compared with inorganic electronics if they are to become commercially viable
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| 18. |
- Berggren, Magnus, 1968-, et al.
(författare)
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Electrochemical Surface Switches and Electronic Ion Pumps Based on Conjugated Polymers
- 2009. - 1
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Ingår i: Organic Electronics in Sensors and Biotechnology. - : McGraw-Hill. - 9780071596756 - 0071596755 ; , s. 395-406
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The latest in organic electronics-based sensing and biotechnology Develop high-performance, field-deployable organic semiconductor-based biological, chemical, and physical sensor arrays using the comprehensive information contained in this definitive volume. Organic Electronics in Sensors and Biotechnology presents state-of-the-art technology alongside real-world applications and ongoing R & D. Learn about light, temperature, and pressure monitors, integrated flexible pyroelectric sensors, sensing of organic and inorganic compounds, and design of compact photoluminescent sensors. You will also get full details on organic lasers, organic electronics in memory elements, disease and pathogen detection, and conjugated polymers for advancing cellular biology. Monitor organic and inorganic compounds with OFETs Characterize organic materials using impedance spectroscopy Work with organic LEDs, photodetectors, and photovoltaic cells Form flexible pyroelectric sensors integrated with OFETs Build PL-based chemical and biological sensing modules and arrays Design organic semiconductor lasers and memory elements Use luminescent conjugated polymers as optical biosensors Deploy polymer-based switches and ion pumps at the microfluidic level
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| 19. |
- Berggren, Magnus, 1968-, et al.
(författare)
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Electronics turns over a new leaf
- 2001
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Ingår i: Physics world. - 0953-8585 .- 2058-7058. ; 14, s. 21-22
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Tidskriftsartikel (refereegranskat)
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| 20. |
- Berggren, Magnus, 1968-, et al.
(författare)
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How conducting polymer electrodes operate
- 2019
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Ingår i: Science. - Washington, DC, United States : American Association for the Advancement of Science (A A A S). - 0036-8075 .- 1095-9203. ; 364:6437, s. 233-234
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
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| 21. |
- Berggren, Magnus, Professor, 1968-, et al.
(författare)
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In Vivo Organic Bioelectronics for Neuromodulation
- 2022
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Ingår i: Chemical Reviews. - : American Chemical Society (ACS). - 0009-2665 .- 1520-6890. ; 122:4, s. 4826-4846
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Forskningsöversikt (refereegranskat)abstract
- The nervous system poses a grand challenge for integration with modern electronics and the subsequent advances in neurobiology, neuroprosthetics, and therapy which would become possible upon such integration. Due to its extreme complexity, multifaceted signaling pathways, and similar to 1 kHz operating frequency, modern complementary metal oxide semiconductor (CMOS) based electronics appear to be the only technology platform at hand for such integration. However, conventional CMOS-based electronics rely exclusively on electronic signaling and therefore require an additional technology platform to translate electronic signals into the language of neurobiology. Organic electronics are just such a technology platform, capable of converting electronic addressing into a variety of signals matching the endogenous signaling of the nervous system while simultaneously possessing favorable material similarities with nervous tissue. In this review, we introduce a variety of organic material platforms and signaling modalities specifically designed for this role as "translator" , focusing especially on recent implementation in in vivo neuromodulation. We hope that this review serves both as an informational resource and as an encouragement and challenge to the field.
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| 22. |
- Berggren, Magnus, 1968-, et al.
(författare)
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Light amplification in organic thin films using cascade energy transfer
- 1997
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 389, s. 466-469
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Tidskriftsartikel (refereegranskat)abstract
- There is currently renewed interest in the development of lasers using solid-state organic and polymeric materials as the gain media. These materials have a number of properties that make them good candidates for such applications — for example, emission bands that are displaced (via a Stokes shift) from absorption bands, and the ease with which the emitting species can be embedded in a suitable host material1, 2, 3, 4, 5. But despite these advantages, the threshold power densities required for light amplification that have been reported so far have been high6, 7, 8. Here we describe an approach, based on energy transfer between molecular species, that can lower the threshold for stimulated emission and laser action while improving markedly the waveguiding properties of the active material. In our materials, an initial molecular excited state is generated in the host compound by absorption of light; this state is then resonantly and non-radiatively transferred down in energy (through one or more steps) between suitably matched dye molecules dispersed in the host, so ensuring that the absorption losses at the final emission wavelengths are very small. Such composite gain media provide provide broad tunability of the emission wavelength, and also decouple the optical emission properties from the transport properties, so providing greater flexibility for the design of future electrically driven device structures.
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| 23. |
- Berggren, Magnus, 1968-, et al.
(författare)
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Organic bioelectronics based on Mixed Ion–Electron conductors
- 2019. - 4
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Ingår i: Conjugated polymers. - Boca Raton : CRC Press. - 9780429190520 ; , s. 679-696
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter focuses on two specific areas of organic mixed ion–electron conductors: surfaces and scaffolds for controlling cell cultures, and “iontronic”-controlled delivery of ions and biomolecules. It draws on iontronic technology based on ion exchange materials, which is compatible with physiological salt concentrations. Iontronics is attractive for bioelectronic applications, as it provides a means for the manipulation of flows of ions and charged biomolecules – species that can possess chemical and biological functionality. The organic electronic ion pump (OEIP) is a delivery device where charged (bio)molecules are transported within a polyelectrolyte membrane. The electronic control of the delivery flux, together with micrometer-sized channel outlets, enables OEIPs to achieve high spatiotemporal resolution; biomolecule delivery can be tightly controlled to a specific site and dose amount. High spatiotemporal control of ion and biomolecule concentrations is attractive for a wide range of in vitro studies of biological systems.??
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| 24. |
- Berggren, Magnus, 1968-, et al.
(författare)
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Organic laser based on lithographically defined photonic-bandgap resonators
- 1998
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Ingår i: Electronics Letters. - : IEEE. - 0013-5194 .- 1350-911X. ; 34:1, s. 90-91
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Tidskriftsartikel (refereegranskat)abstract
- The authors report the fabrication and characteristics of organic solid-state waveguide lasers with feedback from a photolithographically defined rhomboid photonic bandgap lattice. The lattice is formed by etching holes of depth 10-40 nm in SiO2 and filling them with the organic gain medium. The gain medium is part of a planar waveguide formed by air/organic layer/SiO2.
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| 25. |
- Berggren, Magnus, 1968-, et al.
(författare)
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Organic materials for printed electronics
- 2007
-
Ingår i: Nature Materials. - : Springer Science and Business Media LLC. - 1476-1122 .- 1476-4660. ; 6:1, s. 3-5
-
Tidskriftsartikel (refereegranskat)abstract
- Organic materials can offer a low-cost alternative for printed electronics and flexible displays. However, research in these systems must exploit the differences — via molecular-level control of functionality — compared with inorganic electronics if they are to become commercially viable. Introduction Conducting and semiconducting organic materials, both polymers and molecules, are being considered for a vast array of electronic applications. The first examples, such as displays in mobile appliances, have found their way to market as replacements for traditional components in existing products. Organic electronics distinguishes itself from traditional electronics because one can define functionality at the molecular level, process the materials from solution, and make displays and circuits that are completely flexible. So far, very little of the uniqueness of organic electronics is expressed in the products promoted as manufacturable; why? One important opportunity for organic electronics is the area of radiofrequency identification (RFID) manufactured using an all-in-line printing process. This technology comprises fast-switching transistors, antennas operating at frequencies above 100 kHz, memory, and so on, all integrated into a plastic foil. The present target in many organic electronics labs around the world is to develop the high-speed (>10 kHz) transistors critical for such devices. The use of organic transistors instead of their inorganic equivalents is motivated by cost. So far, little effort has been devoted to exploring organic electronics in terms of its true unique electronic functionality and the possibility to add electronics to surfaces previously considered electronically inactive. For instance, paper is produced at speeds exceeding 100 km h-1 and is converted into packages and printed media at manufacturing flows typically above 100 m min-1. Adding organic electronics onto, for instance, the paper surface during the paper conversion process would demonstrate the true uniqueness of organic electronics, both from a manufacturing and an application point of view. Retail chains and transportation companies desperately seek a printed electronic technology to provide better safety and security features on packages and automatically track and trace products all the way from the manufacturer to the end customer. The financial losses related to counterfeiting, failure in transportation and damaged packages is comparable to the overall profits made on the product contained in the package. In addition, printed electronics could potentially guide the end-user to properly use the product and to guarantee brand authenticity, for example through an interactive user's guide, and electronic features to replace existing security devices such as the holographic stickers commonly used in packages and bank notes today. It turns out that, for many of these applications, high-frequency signal-processing is not required; 10 ms to 1 s response times are appropriate. These are goals that a very simple printed electronics technology may be able to fill. Silicon-based RFID devices are currently used in high-end products, but are prohibitively expensive for commodities such as food at the consumer package level. Thus, the potential value for printed organic electronics seems to exist if the expense can be kept down. For instance, TetraPak, who produces more than 100 billion packages every year, estimates that the costs for additional security and safety features cannot exceed about 0.2 Eurocents per package (Istvan Ulvros, TetraPak, private communication). Much of the research in organic electronics aims to optimise inherent charge transport and efficiency characteristics of the materials already in use in individual devices. This work has pushed the solar energy-to-electricity power-conversion efficiency in organic solar cells close to 5% (ref. 1) and the luminous efficiency of plastic luminescent devices to around 25 cd A-1 (ref. 2). Organic electrochromic displays now perform extraordinarily well in terms of colour contrast, memory and stability3, and polymer transistors easily run at speeds beyond 100 kHz (ref.4). These results have been achieved by improving the performance at the individual device level. Rarely are integrated circuits or high-volume manufacturing conditions considered in the research. Typically, a series of more than ten patterning, material deposition and post-processing steps are required to make one kind of device. The tradition has been to develop specific materials that exclusively function well in only one device type. RFID circuits (for example) typically require rectifiers, antennas, powering devices, transistors for signal processing, encapsulation layers and in some cases also displays. Merging today's efforts conducted at the organic electronics device level would then result in a production route that would include perhaps 50 (or even more) discrete manufacturing steps. Unfortunately, the cost for a label requiring several tens of patterning steps including exotic organic electronic materials is not compatible with the value and costs of packages. In traditional printers, typically five to ten printing stations are available in series (Fig. 1). Each station also includes one or two convection, infrared or ultraviolet curing steps. At ordinary printing speeds (10 to 200 m min-1) the substrate spends on the order of a tenth to several seconds in each printing station. During this time, registration, material deposition and post-processing must take place. The value structure in printing technology means that the cost for printing scales at least linearly with the number of printing steps. The yield and systematic errors in printing technology becomes a nightmare beyond ten printing steps. The cost for materials such as inks, substrates and coatings is a considerable part of the entire product value. Our own calculations indicate that each individual RFID label would cost more than 10 Eurocents (Lars-Olov Hennerdal, Acreo, private communication).
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| 26. |
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| 27. |
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| 28. |
- Brooke, Robert, 1989-, et al.
(författare)
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Nanocellulose and PEDOT:PSS composites and their applications
- 2023
-
Ingår i: Polymer Reviews. - : Taylor and Francis Ltd.. - 1558-3724 .- 1558-3716. ; :2, s. 437-
-
Tidskriftsartikel (refereegranskat)abstract
- The need for achieving sustainable technologies has encouraged research on renewable and biodegradable materials for novel products that are clean, green, and environmentally friendly. Nanocellulose (NC) has many attractive properties such as high mechanical strength and flexibility, large specific surface area, in addition to possessing good wet stability and resistance to tough chemical environments. NC has also been shown to easily integrate with other materials to form composites. By combining it with conductive and electroactive materials, many of the advantageous properties of NC can be transferred to the resulting composites. Conductive polymers, in particular poly(3,4-ethylenedioxythiophene:poly(styrene sulfonate) (PEDOT:PSS), have been successfully combined with cellulose derivatives where suspensions of NC particles and colloids of PEDOT:PSS are made to interact at a molecular level. Alternatively, different polymerization techniques have been used to coat the cellulose fibrils. When processed in liquid form, the resulting mixture can be used as a conductive ink. This review outlines the preparation of NC/PEDOT:PSS composites and their fabrication in the form of electronic nanopapers, filaments, and conductive aerogels. We also discuss the molecular interaction between NC and PEDOT:PSS and the factors that affect the bonding properties. Finally, we address their potential applications in energy storage and harvesting, sensors, actuators, and bioelectronics. © 2022 The Author(s).
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| 29. |
- Brooke, Robert, 1989-, et al.
(författare)
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Supercapacitors on demand : All-printed energy storage devices with adaptable design
- 2019
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Ingår i: Flexible and Printed Electronics. - : Institute of Physics Publishing. - 2058-8585. ; 4:1
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Tidskriftsartikel (refereegranskat)abstract
- Demands on the storage of energy have increased for many reasons, in part driven by household photovoltaics, electric grid balancing, along with portable and wearable electronics. These are fast-growing and differentiated applications that need large volume and/or highly distributed electrical energy storage, which then requires environmentally friendly, scalable and flexible materials and manufacturing techniques. However, the limitations on current inorganic technologies have driven research efforts to explore organic and carbon-based alternatives. Here, we report a conducting polymer:cellulose composite that serves as the active material in supercapacitors which has been incorporated into all-printed energy storage devices. These devices exhibit a specific capacitance of ≈90 F g -1 and an excellent cyclability (>10 000 cycles). Further, a design concept coined 'supercapacitors on demand' is presented, which is based on a printing-cutting-folding procedure, that provides us with a flexible production protocol to manufacture supercapacitors with adaptable configuration and electrical characteristics.
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| 30. |
- Carson, Dean, et al.
(författare)
-
Umeå University's proposed "Rural Stream" : An effective alternative to the longitudinal integrated clerkship model for small rural communities?
- 2020
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Ingår i: Education for Health. - : Wolters Kluwer. - 1357-6283 .- 1469-5804. ; 33:1, s. 3-7
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Tidskriftsartikel (refereegranskat)abstract
- Background: Umeå University Faculty of Medicine (UUFM), Sweden, has a regionalized medical program in which students spend the final 2½ years of their undergraduate degree in district hospitals. In late 2018, UUFM started a "rural stream" pilot exposing students to smaller rural locations.Methods: The objectives are to deliver the benefits for medical education and rural workforce development that have been observed in longitudinal integrated clerkships (LICs) while maintaining consistency between learning experiences in the main campus, regional campuses, and rural locations. This article compares the UUFM rural stream with those typical of the LICs described in the medical education literature. Comparisons are made in terms of the four key criteria for LIC success, and additional characteristics including peer and interprofessional learning, "'continuity," and curriculum development.Results: The rural stream has elements of length, immersion, position in the degree program, and community engagement that are both similar to, and different from, LICs. Key challenges are to ensure that participating students create close relationships with host medical facilities and communities. The rural stream also has some potential advantages, particularly in relation to team learning.Discussion: Alternatives to the LIC rural stream model as typically described in the literature may be required to allow for immersive medical education to occur in smaller rural communities and to be suitable for medical schools with more traditional approaches to education.
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| 31. |
- Chen, Miaoxiang, 1962-, et al.
(författare)
-
1 micron wavelength photo- and electroluminescence from a conjugated polymer
- 2004
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 84:18, s. 3570-3572
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Tidskriftsartikel (refereegranskat)abstract
- We report photo- and electroluminescence from an alternating conjugated polymer consisting of fluorene units and low-band gap donor-acceptor-donor (D-A-D) units. The D-A-D segment includes two electron-donating thiophene rings combined with a thiadiazolo-quinoxaline unit, which is electron withdrawing to its nature. The resulting polymer is conjugated and has a band gap of 1.27 eV. The corresponding electro- and photoluminescence spectra both peak at approximately 1 mum. Light-emitting diodes, based on a single layer of the polymer, demonstrated external quantum efficiencies from 0.03% to 0.05%.
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| 32. |
- Chen, Miaoxiang, 1962-, et al.
(författare)
-
Electric current rectification by an all-organic electrochemical device
- 2002
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 81, s. 2011-2013
-
Tidskriftsartikel (refereegranskat)abstract
- An all-organic printed electrochemical rectifier is reported. The device is based on a patterned layer of poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate) (PEDOT:PSS) that interfaces a patterned electrolyte top layer. Overlap between the electrolyte layer and the conducting polymer pattern results in the formation of two electrochemically active areas within the conducting polymer pattern. When bias voltage is applied across the conducting polymer pattern, the PEDOT in the negatively biased areas is reduced electrochemically, while the PEDOT in the positively biased area is further oxidized. Reducing PEDOT from its p-doped, pristine state to the neutral state results in a marked loss of electrical conductivity. Due to the unsymmetrical device geometry, the current through the device may be shut off for one polarity of applied bias voltage with an electrical current rectification ratio of 100 compared to the opposite polarity. The output characteristics of a corresponding half wave rectifier as well as those from a full wave bridge rectifier show stable performance at frequencies below 15 Hz.
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| 33. |
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| 34. |
- Chen, Miaoxiang, 1962-, et al.
(författare)
-
High carrier mobility in low band gap polymer-based field-effect transistors
- 2005
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 87:25, s. 252105-1-252105-3
-
Tidskriftsartikel (refereegranskat)abstract
- A conjugated polymer with a low band gap of 1.21 eV, i.e., absorbing infrared light, is demonstrated as active material in field-effect transistors (FETs). The material consists of alternating fluorene units and low band gap segments with electron donor-acceptor-donor units composed of two electron-donating thiophene rings attached on both sides of a thiadiazolo-quinoxaline electron-acceptor group. The polymer is solution-processable and air-stable; the resulting FETs exhibit typical p-channel characteristics and field-effect mobility of 0.03 cm2 V−1 s−1.
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| 35. |
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| 36. |
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| 37. |
- Cherian, Dennis, 1989-
(författare)
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Expanding the versatility and functionality of iontronic devices
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Biological systems rarely use electrons as signal regulators, most of the transport and communication in these system utilize ions. The discovery of conjugated polymers and polyelectrolytes and their unique properties of mixed ionic electronic properties opened the possibility of using these in the domain of bioelectronics, which paved the way for the field of organic bioelectronics. After the introduction of the organic electronic ion pump (OEIP) in 2007, which utilizes both the ionic properties of conjugated polymers and polyelectrolytes, the new field of “iontronics” evolved. TheOEIP is an organic polymer-based delivery system based on electrophoretic transport of biologically relevant and ionically charged species, without fluid flow and with high spatial, temporal, and dosage precision. These devices have been extensivelystudied for the past 14 years and have found numerous demonstrations in in vivo and in vitro delivery of bio-relevant ions for therapeutic application. This has, in parallel, resulted in the development of custom materials for ion exchange membranes (IEMs) within the OEIP.This thesis focuses on IEMs and device development of OEIPs. Specific focus is given to process development through device design and fabrication through conventional and unconventional technologies. Conventional technologies include microfabrication through photolithography, etching, and thin-film evaporation. Unconventional fabrication techniques include screen printing, inkjet printing, stencil, and laser patterning. In this thesis, we have also scouted a new area of research to utilize the ion-selective properties of polyelectrolytes. Here we discuss a new ion detection technique using IEMs and ion transport based on diffusion coefficients and impedance measurement at a specific frequency using impedance spectroscopy for faster ion detection with low voltage (1–40 V) and liquid-flow-free transport. Further exploring the area of IEMs, we have realized that less attention has been given to stretchable IEMs, even though such materials could find enormous applications in the field of organic bioelectronics and can be used in association with many stretchable electronics applications like stretchable displays and energy storage devices. Current IEMs lack the conformability and stretchability to be used for implantable applications, e.g., including lungs, heart, muscle, soft or brain implants, joints, etc. Keeping this in mind we also discuss our approach for the development of a stretchable IEM. Finally, we focus on developing a hybrid fabrication protocol of flexible OEIPs with micropatterning techniques and inkjet-printed membranes. These OEIPs were fabricated and the functionality was validated by the cell response after the delivery of a nerve-blocking agent to cells in vitro. To date, OEIPs have been fabricated by micropatterning and labor-intensive manual techniques, impeding the budding application areas of this propitious technology. To address this issue, a novel approach to the fabrication of the OEIPs using screen-printing technology is also explored in this thesis. In summary, we were able to successfully explore the field of ion-exchange membranesand put forward a new technique for ion detection and stretchable IEMs for future applications. Fabrication of OEIPs was also examined which resulted in the development of a hybrid fabrication protocol with inkjet printing for OEIPs and a robust fully screen printed OEIPs with high manufacturing yield (>90%) for industrial-scale manufacturing.
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| 38. |
- Cherian, Dennis, 1989-, et al.
(författare)
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Flexible Organic Electronic Ion Pump Fabricated Using Inkjet Printing and Microfabrication for Precision In Vitro Delivery of Bupivacaine
- 2023
-
Ingår i: Advanced Healthcare Materials. - : John Wiley and Sons Inc. - 2192-2640 .- 2192-2659. ; 12:24, s. 2300550-
-
Tidskriftsartikel (refereegranskat)abstract
- The organic electronic ion pump (OEIP) is an on-demand electrophoretic drug delivery device, that via electronic to ionic signal conversion enables drug delivery without additional pressure or volume changes. The fundamental component of OEIPs is their polyelectrolyte membranes which are shaped into ionic channels that conduct and deliver ionic drugs, with high spatiotemporal resolution. The patterning of these membranes is essential in OEIP devices and is typically achieved using laborious microprocessing techniques. Here, the development of an inkjet printable formulation of polyelectrolyte is reported, based on a custom anionically functionalized hyperbranched polyglycerol (i-AHPG). This polyelectrolyte ink greatly simplifies the fabrication process and is used in the production of free-standing OEIPs on flexible polyimide (PI) substrates. Both i-AHPG and the OEIP devices are characterized, exhibiting favorable iontronic characteristics of charge selectivity and the ability to transport aromatic compounds. Further, the applicability of these technologies is demonstrated by the transport and delivery of the pharmaceutical compound bupivacaine to dorsal root ganglion cells with high spatial precision and effective nerve blocking, highlighting the applicability of these technologies for biomedical scenarios. © 2023 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH.
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| 39. |
- Crispin, Annica, 1972-, et al.
(författare)
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Transition between energy level alignment regimes at a low band gap polymer-electrode interfaces
- 2006
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 89:21
-
Tidskriftsartikel (refereegranskat)abstract
- The energy level alignment at interfaces between a low band gap conjugated polymer and various electrodes is investigated using ultraviolet photoemission spectroscopy. When the electrode work function is lower (higher) than the negative (positive) polaronic level of the polymer, the Fermi level is pinned to the negative (positive) polaronic level. These Fermi level pinning regimes suggest a spontaneous electron transfer from or towards the electrode resulting in an interfacial dipole of different orientation. On the contrary, when the substrate work function is intermediate, there is no charge transfer and the energy level alignment across the interface follows the Schottky-Mott limit. © 2006 American Institute of Physics.
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| 40. |
- Crispin, Xavier, 1972-, et al.
(författare)
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Photochromic Diodes
- 2006. - 2
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Ingår i: Semiconducting Polymers. - Weinheim, Tyskland : WileyVCH Verlag GmbH & Co. - 9783527312719 - 3527312714 ; , s. 579-611
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The field of semiconducting polymers has attracted many researchers from a diversity of disciplines. Printed circuitry, flexible electronics and displays are already migrating from laboratory successes to commercial applications, but even now fundamental knowledge is deficient concerning some of the basic phenomena that so markedly influence a device's usefulness and competitiveness. This two-volume handbook describes the various approaches to doped and undoped semiconducting polymers taken with the aim to provide vital understanding of how to control the properties of these fascinating organic materials. Prominent researchers from the fields of synthetic chemistry, physical chemistry, engineering, computational chemistry, theoretical physics, and applied physics cover all aspects from compounds to devices.Since the first edition was published in 2000, significant findings and successes have been achieved in the field, and especially handheld electronic gadgets have become billion-dollar markets that promise a fertile application ground for flexible, lighter and disposable alternatives to classic silicon circuitry. The second edition brings readers up-to-date on cutting edge research in this field.
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| 41. |
- Crispin, Xavier, 1972-, et al.
(författare)
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The origin of the high conductivity of poly(3,4-ethylenedioxythiophene)- poly(styrenesulfonate) (PEDOT-PSS) plastic electrodes
- 2006
-
Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 18:18, s. 4354-4360
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Tidskriftsartikel (refereegranskat)abstract
- The development of printed and flexible (opto)electronics requires specific materials for the device's electrodes. Those materials must satisfy a combination of properties. They must be electrically conducting, transparent, printable, and flexible. The conducting polymer poly(3,4-ethylenedioxythiophene) - poly-(styrenesulfonate) (PEDOT-PSS) is known as a promising candidate. Its conductivity can be increased by 3 orders of magnitude by the secondary dopant diethylene glycol (DEG). This "secondary doping" phenomenon is clarified in a combined photoelectron spectroscopy and scanning probe microscopy investigation. PEDOT-PSS appears to form a three-dimensional conducting network explaining the improvement of its electrical property upon addition of DEG. Polymer light emitting diodes are successfully fabricated using the transparent plastic PEDOT-PSS electrodes instead of the traditionally used indium tin oxide. © 2006 American Chemical Society.
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| 42. |
- Datta-Chaudhuri, Timir, et al.
(författare)
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The Fourth Bioelectronic Medicine Summit "Technology Targeting Molecular Mechanisms" : current progress, challenges, and charting the future
- 2021
-
Ingår i: Bioelectronic medicine. - : BioMed Central. - 2332-8886. ; 7:1
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- There is a broad and growing interest in Bioelectronic Medicine, a dynamic field that continues to generate new approaches in disease treatment. The fourth bioelectronic medicine summit "Technology targeting molecular mechanisms" took place on September 23 and 24, 2020. This virtual meeting was hosted by the Feinstein Institutes for Medical Research, Northwell Health. The summit called international attention to Bioelectronic Medicine as a platform for new developments in science, technology, and healthcare. The meeting was an arena for exchanging new ideas and seeding potential collaborations involving teams in academia and industry. The summit provided a forum for leaders in the field to discuss current progress, challenges, and future developments in Bioelectronic Medicine. The main topics discussed at the summit are outlined here.
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| 43. |
- Diacci, Chiara, 1992-
(författare)
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Organic Bioelectronic Devices for Selective Biomarker Sensing : Towards Integration with Living Systems
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Inorganic materials have been the main players of the semiconductor industry for the past forty years. However, there has been a continuous interest and growth in the research and in the application of organic semiconductors (OSCs) as active materials in electronic devices, due to the possibility to process these materials at low temperature on flexible substrates, fabricate them on large-area, and upscale their fabrication using cost-effective strategies such as printing. Because of these features, organic electronic devices are rapidly emerging as biosensors for biomarkers, with a high potential for becoming a high-throughput tool even deployable at the point-of-care. One of the most used and studied platforms is the organic electrochemical transistor (OECT). OECTs have been largely used as biosensors in order to transduce and amplify electrical signals or detect biological analytes upon proper functionalization with specific biorecognition units. OECTs can operate at low voltages, are easy to fabricate on different substrates, and are compatible with the aqueous environment, and can therefore be interfaced with living systems, ranging from mammals to plants. The OECT device configuration includes a gate electrode that modulates the current in the channel through an electrolyte, which can be not only a buffered solution but even a complex biological fluid. When OECTs are operated as biosensors, the sensing mechanism relies on the current variation generated from specific reactions with the analyte of interest. These devices are paving the way to the development of point-of-care technologies and portable biosensors with fast and label-free detection. Moreover, OECTs can help to reveal new biological insight and allow a better understanding of physiological processes. During my PhD, I focused on design, fabrication, and validation of different OECT-based biosensors for the detection of biomarkers that are relevant for healthcare applications, thus showing their high potential as a proper sensing platform. We developed sensors towards different analytes, ranging from small molecules to proteins, with ad hoc designed materials strategies to endow the device with selectivity towards the species of interest. Most notably, I also demonstrated the possibility of integrating OECTs in plants, as an example of interfacing these biosensors with living systems. In the first two papers, we developed screen printed OECTs, presenting PEDOT:PSS as the semiconducting material on the channel. In the first case, the device also featured a PEDOT:PSS gate electrode which was further functionalized with biocompatible gelatin and the enzyme urease to ensure selectivity toward the analyte of interest, namely urea. The biosensor was able to monitor increasing urea concentrations with a limit of detection of 1 µM. In the second paper the screen-printed carbon gate electrode was first modified with platinum and then we ensured selectivity towards the analyte uric acid, a relevant biomarker for wound infection, by entrapping urate oxidase in a dual-ionic-layer hydrogel membrane to filter out charged interfering agents. The biosensor exhibited a 4.5 µM limit of detection and selectivity even in artificial wound exudate. In the third paper we designed an interleukin-6 (IL6) OECT based biosensor able to detect the cytokine down to the pM regime in PBS buffer. The mechanism of detection relied on the specific binding between an aptamer, used as sensing unit on the gate electrode, and the IL6 in solution, allowing for detection ranging from physiological to pathological levels. In the last two papers we developed OECT based biosensors to be interfaced with the plant world. In the fourth paper we presented a glucose sensor, based on the enzyme glucose oxidase (GOx) to detect glucose export from chloroplasts. In particular, we demonstrated real-time glucose monitoring with temporal resolution of 1 minute in complex media. In the fifth paper, we developed implantable OECT-based sugar sensors for in vivo real-time monitoring of sugar transport in poplar trees. The biosensors presented a multienzyme-functionalized gate endowing the device with specificity towards glucose and sucrose. Most notably, the OECT sensors did not cause a significant wound response in the plant, allowing us to demonstrate that OECT-based sensors are attractive tools for studying transport kinetics in plants, in vivo and real-time.
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| 44. |
- Fahlman, Mats, 1967-, et al.
(författare)
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Interfaces in organic electronics
- 2019
-
Ingår i: Nature Reviews Materials. - : Nature Publishing Group. - 2058-8437. ; 4:10, s. 627-650
-
Forskningsöversikt (refereegranskat)abstract
- Undoped, conjugated, organic molecules and polymers possess properties of semiconductors, including the electronic structure and charge transport, which can be readily tuned by chemical design. Moreover, organic semiconductors (OSs) can be n-doped or p-doped to become organic conductors and can exhibit mixed electronic and ionic conductivity. Compared with inorganic semiconductors and metals, organic (semi)conductors possess a unique feature: no insulating oxide forms on their surface when exposed to air. Thus, OSs form clean interfaces with many materials, including metals and other OSs. OS–metal and OS–OS interfaces have been intensely investigated over the past 30 years, from which a consistent theoretical description has emerged. Since the 2000s, increased attention has been paid to interfaces in organic electronics that involve dielectrics, electrolytes, ferroelectrics and even biological organisms. In this Review, we consider the central role of these interfaces in the function of organic electronic devices and discuss how the physico-chemical properties of the interfaces govern the interfacial transport of light, excitons, electrons and ions, as well as the transduction of electrons into the molecular language of cells.
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| 45. |
- Galliani, Marina, et al.
(författare)
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Flexible Printed Organic Electrochemical Transistors for the Detection of Uric Acid in Artificial Wound Exudate
- 2020
-
Ingår i: Advanced Materials Interfaces. - : Wiley-VCH Verlag. - 2196-7350. ; 7:23
-
Tidskriftsartikel (refereegranskat)abstract
- Low-cost, minimally invasive sensors able to provide real-time monitoring of wound infection can enable the optimization of healthcare resources in chronic wounds management. Here, a novel printed organic electrochemical transistors (OECT) biosensor for monitoring uric acid (UA), a bacterial infection biomarker in wounds, is demonstrated in artificial wound exudate. The sensor exploits the enzymatic conversion of UA to 5-hydroxyisourate, catalyzed by Uricase entrapped in a dual-ionic-layer hydrogel membrane casted onto the gate. The sensor response is based on the catalytic oxidation of the hydrogen peroxide, generated as part of the Uricase regeneration process, at the Pt modified gate. The proposed dual membrane avoids the occurrence of nonspecific faradic reactions as, for example, the direct oxidation of UA or other electroactive molecules that would introduce a potentially false negative response. The biosensor is robust and its response is reproducible both in phosphate buffer saline and in complex solutions mimicking the wound exudate. The sensor has a high sensitivity in the range encompassing the pathological levels of UA in wounds (<200 μm) exhibiting a limit of detection of 4.5 μm in artificial wound exudate. All these characteristics make this OECT-based biosensor attractive for wound monitoring interfaced to the patient.
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| 46. |
- Gerasimov, Jennifer, et al.
(författare)
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An Evolvable Organic Electrochemical Transistor for Neuromorphic Applications
- 2019
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Ingår i: Advanced Science. - : Wiley-VCH Verlagsgesellschaft. - 2198-3844. ; 6:7
-
Tidskriftsartikel (refereegranskat)abstract
- An evolvable organic electrochemical transistor (OECT), operating in the hybrid accumulation-depletion mode is reported, which exhibits short-term and long-term memory functionalities. The transistor channel, formed by an electropolymerized conducting polymer, can be formed, modulated, and obliterated in situ and under operation. Enduring changes in channel conductance, analogous to long-term potentiation and depression, are attained by electropolymerization and electrochemical overoxidation of the channel material, respectively. Transient changes in channel conductance, analogous to short-term potentiation and depression, are accomplished by inducing nonequilibrium doping states within the transistor channel. By manipulating the input signal, the strength of the transistor response to a given stimulus can be modulated within a range that spans several orders of magnitude, producing behavior that is directly comparable to short- and long-term neuroplasticity. The evolvable transistor is further incorporated into a simple circuit that mimics classical conditioning. It is forecasted that OECTs that can be physically and electronically modulated under operation will bring about a new paradigm of machine learning based on evolvable organic electronics.
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| 47. |
- Gerasimov, Jennifer Yevgenia, 1985-, et al.
(författare)
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Rational Materials Design for In Operando Electropolymerization of Evolvable Organic Electrochemical Transistors
- 2022
-
Ingår i: Advanced Functional Materials. - : John Wiley and Sons Inc. - 1616-301X .- 1616-3028. ; 32
-
Tidskriftsartikel (refereegranskat)abstract
- Organic electrochemical transistors formed by in operando electropolymerization of the semiconducting channel are increasingly becoming recognized as a simple and effective implementation of synapses in neuromorphic hardware. However, very few studies have reported the requirements that must be met to ensure that the polymer spreads along the substrate to form a functional conducting channel. The nature of the interface between the substrate and various monomer precursors of conducting polymers through molecular dynamics simulations is investigated, showing that monomer adsorption to the substrate produces an increase in the effective monomer concentration at the surface. By evaluating combinatorial couples of monomers baring various sidechains with differently functionalized substrates, it is shown that the interactions between the substrate and the monomer precursor control the lateral growth of a polymer film along an inert substrate. This effect has implications for fabricating synaptic systems on inexpensive, flexible substrates. © 2022 The Authors.
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| 48. |
- Ghorbani Shiraz, Hamid, 1989-, et al.
(författare)
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3R-TaS2 as an Intercalation-Dependent Electrified Interface for Hydrogen Reduction and Oxidation Reactions
- 2022
-
Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 126:40, s. 17056-17065
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Tidskriftsartikel (refereegranskat)abstract
- Hydrogen technology, as a future breakthrough for the energy industry, has been defined as an environmentally friendly, renewable, and high-power energy carrier. The green production of hydrogen, which mainly relies on electrocatalysts, is limited by the high cost and/ or the performance of the catalytic system. Recently, studies have been conducted in search of bifunctional electrocatalysts accelerating both the hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR). Herein, we report the investigation of the high efficiency bifunctional electrocatalyst TaS2 for both the HER and the HOR along with the asymmetric effect of inhibition by organic intercalation. The linear organic agent, to boost the electron donor property and to ease the process of intercalation, provides a higher interlayer gap in the tandem structure of utilized nanosheets. XRD and XPS data reveal an increase in the interlayer distance of 22%. The HER and the HOR were characterized in a Pt group metal-free electrochemical system. The pristine sample shows a low overpotential of -0.016 Vat the onset. The intercalated sample demonstrates a large shift in its performance for the HER. It is revealed that the intercalation is a potential key strategy for tuning the performance of this family of catalysts. The inhibition of the HER by intercalation is considered as the increase in the operational window of a water-based electrolyte on a negative electrode, which is relevant to technologies of electrochemical energy storage.
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| 49. |
- Ghorbani Shiraz, Hamid, 1989-
(författare)
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Electrochemical reduction of protons and organic molecules in hydrogen technologies : Liquid Organic Hydrogen carrier and Hydrogen Evolution
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In accordance with preventable actions to mitigate the effect of climate change in the modern societal applications, renewable energy is an unavoidable and decisive factor in the energy industry. The energy sources that offer non-depleted and environment-friendly pathways for the energy sector are in focus. Amongst, hydrogen has been defined as one of the best candidates to meet the criteria such as high energy-content and zero-emission of CO2, and of course, renewability. In this work, we focused on the areas of hydrogen generation and hydrogen storage.In the first part, we employed an inorganic electrocatalyst (nanosheets) to drive the hydrogen evolution reaction (HER), where we proved that the overpotential of few millivolts (0.016 V) is enough to run the HER reaction. We studied the effect of interlayer gap (for the nanosheets) on the catalytic performance. The chemical intercalation showed a huge effect for the suppression of the HER, which could be applicable for the devices like batteries the formation of any gaseous species has detrimental effect on the performance. It should not be left unmentioned that the measurements were carried out in a platinum group metal free (PGM-free) system, where graphite felt were used as a counter electrode, to avoid any platinum contamination. Next, we investigated the effect of oxygen poisoning on both pristine electrocatalyst and intercalated one. The XPS and UPS measurements confirmed the formation of oxygen-containing groups on the electrocatalysts. Electrochemical measurements showed the increase of the overpotential toward HER as the electrocatalysts are exposed to air for longer time. However, study of the hydrogen oxidation reaction (HOR) showed that there is an optimum concentration of oxygenic functional groups that can lead to a high current density of HOR process. The study of exchange current density showed that, after 10 days of exposure of electrocatalyst to atmospheric air, pristine sample possesses the best performance toward HER and intercalated one shows the highest performance for the HOR. In the other section, hydrogen storage for the organic redox-active molecule (dissolved in organic solvent) was studied. One of the main problems in hydrogen economy concept, is the storage of the hydrogen for transportation. The new concept of Liquid Organic Hydrogen Carrier (LOHC) offers a low-cost and safe approach to this challenge. Herein, we demonstrated an electrochemical pathway to hydrogenate the organic system via conversion of proton of a proton donor into a covalent-bonded hydrogen, through a proton coupled electron transfer (PCET) reaction of 2nH+ + 2ne¯ + Rox nH2Rred. Here, we studied the 9-fluorenone/fluorenol (Fnone/Fnol) as a model PCET reaction. The electrochemical activation of starting component of (Fnone), through two successive electron transfers was investigated with in-situ and operando spectroscopies purely, and in presence of different proton donors of different reactivity. We succeed to both quantify and qualify the investigated the reaction. The hydrogen release step was demonstrated chemically with the aid of catalyst. To conclude, we employed a PGM-free system to demonstrate and characterize a high performing electrocatalyst for hydrogen evolution. Surprisingly, HOR was revealed to perform well using the oxygen poisoned electrocatalyst for HER. In the other section of this work, an electrochemical assisted synthesis of LOHC, in the lab-scale, was proved. A PCET pathway was conceptualized with mechanistic insight. Our work opens new avenue for the technology of hydrogenation of LOHC as we showed for the first time that this could be realized by electrochemistry without the need of hydrogen gas as a prerequisite. We believe that in the future both works could contribute slightly to the concept of the hydrogen economy.
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| 50. |
- Gomez-Carretero, S., et al.
(författare)
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Correction: Redox-active conducting polymers modulate Salmonella biofilm formation by controlling availability of electron acceptors (vol 3, article number 19, 2017)
- 2018
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Ingår i: npj Biofilms and Microbiomes. - : Nature Publishing Group. - 2055-5008. ; 4:1
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- In the original published article, the author list did not include Karl Svennersten, Kristin Persson, Edwin Jager and Magnus Berggren. After publication, we were notified by the corresponding author that the author list did not accurately reflect the contributions made, and these authors have been added to the author list. The original “Author Contributions” stated that “S.G.C., M.R., and A.R.D. designed research; S.G.C. performed all experiments…” this has been updated to read “S.G.C., K.S., K.M.P., E.W.H.J., M.B., M.R., and A.R.D. designed research; K.S., K.M.P., and E.W.H.J. performed experiments; S.G.C. performed all reported experiments…”. The “Acknowledgements” previously read “We thank K. Svennersten, A. Kader, K. Persson, and M. Berggren for fruitful discussions, and S. Löffler for insightful comments on the manuscript…” and have been updated to state “We thank A. Kader for fruitful discussions and S. Loffler for insightful comments on the manuscript…”. The “Competing Interests” section did not require any amendments. All authors have agreed with this correction statement and authorship change.
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