| 1. |
- Ahmed, A., et al.
(författare)
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Toward High-Performance Triboelectric Nanogenerators by Engineering Interfaces at the Nanoscale : Looking into the Future Research Roadmap
- 2020
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Ingår i: Advanced Materials Technologies. - : Wiley-Blackwell. - 2365-709X. ; 5:11, s. 2000520-
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Tidskriftsartikel (refereegranskat)abstract
- To meet the future need for clean and sustainable energies, there has been considerable interest in the development of triboelectric nanogenerators (TENGs) that scavenge waste mechanical energies. The performance of a TENG at the macroscale is determined by the multifaceted role of surface and interface properties at the nanoscale, whose understanding is critical for the future development of TENGs. Therefore, various protocols from the atomic to the macrolevel for fabrication and tuning of surfaces and interfaces are required to obtain the desired TENG performance. These protocols branch out into three categories: chemical engineering, physical engineering, and structural engineering. Chemical engineering is an affordable and optimal strategy for introducing more surface polarities and higher work functions for the improvement of charge transfer. Physical engineering includes the utilization of surface morphology control, and interlayer interactions, which can enhance the active interfacial area and electron transfer capacity. Structural engineering at the macroscale, which includes device and electrode design/modifications has a considerable effect on the performance of TENGs. Future challenges and promising research directions related to the construction of next-generation TENG devices, taking into consideration “interfaces” are also presented.
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| 2. |
- Annamalai, P. K., et al.
(författare)
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An Overview of Cellulose-Based Nanogenerators
- 2021
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Ingår i: Advanced Materials Technologies. - : John Wiley and Sons Inc. - 2365-709X. ; 6:3
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Tidskriftsartikel (refereegranskat)abstract
- Developing nanogenerators (NGs) is achieved by exploiting the piezoelectric, triboelectric, and pyroelectric effects of both organic and inorganic materials. Many exhibit beneficial electrical properties (dielectric, conductive, or insulating) or have surfaces that are polarizable upon friction or physical contact. Recently, biomass-derived materials and recycled materials, whose electrical activity can be induced, are explored for application in the design of more sustainable, cost-effective, biodegradable, disposable NGs, and have demonstrated a wide range of output (microenergy) power densities. Among them, cellulose, the most abundant biopolymer, is found to offer excellent opportunities for designing and manufacturing NGs with multifunctional capacities. Cellulose can be derived into varied forms with multifunctionalities and physical morphologies. This account provides an overview of how cellulose is utilized in creating NGs based on piezoelectric, triboelectric, and pyroelectric effects. Because the mechanical properties of cellulose are tunable, current research trends on NGs originate with the triboelectric effect. The discussion here focuses on design, fabrication methods, achievable electrical power output, and combinations with other materials and devices. Challenges in efficient fabrication and consistent power densities, and opportunities for integrating different technologies and developing more sustainable (in terms of economic, environmental, and ecological) nature–human–machine interfacial devices are also discussed. © 2021 Wiley-VCH GmbH
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| 3. |
- Arbring Sjöström, Theresia, et al.
(författare)
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A Decade of Iontronic Delivery Devices
- 2018
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Ingår i: Advanced Materials Technologies. - : Wiley. - 2365-709X. ; 3:5
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Forskningsöversikt (refereegranskat)abstract
- In contrast to electronic systems, biology rarely uses electrons as the signal to regulate functions, but rather ions and molecules of varying size. Due to the unique combination of both electronic and ionic/molecular conductivity in conjugated polymers and polyelectrolytes, these materials have emerged as an excellent tool for translating signals between these two realms, hence the field of organic bioelectronics. Since organic bioelectronics relies on the electron-mediated transport and compensation of ions (or the ion-mediated transport and compensation of electrons), a great deal of effort has been devoted to the development of so-called "iontronic" components to effect precise substance delivery/transport, that is, components where ions are the dominant charge carrier and where ionic-electronic coupling defines device functionality. This effort has resulted in a range of technologies including ionic resistors, diodes, transistors, and basic logic circuits for the precisely controlled transport and delivery of biologically active chemicals. This Research News article presents a brief overview of some of these "ion pumping" technologies, how they have evolved over the last decade, and a discussion of applications in vitro, in vivo, and in plantae.
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| 4. |
- 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
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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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| 5. |
- Arbring Sjöström, Theresia, et al.
(författare)
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Miniaturized Ionic Polarization Diodes for Neurotransmitter Release at Synaptic Speeds
- 2020
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Ingår i: Advanced Materials Technologies. - : WILEY. - 2365-709X. ; 5:3
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Tidskriftsartikel (refereegranskat)abstract
- Current neural interfaces rely on electrical stimulation pulses to affect neural tissue. The development of a chemical delivery technology, which can stimulate neural tissue with the bodys own set of signaling molecules, would provide a new level of sophistication in neural interfaces. Such technology should ideally provide highly local chemical delivery points that operate at synaptic speed, something that is yet to be accomplished. Here, the development of a miniaturized ionic polarization diode that exhibits many of the desirable properties for a chemical neural interface technology is reported. The ionic diode shows proper diode rectification and the current switches from off to on in 50 mu s at physiologically relevant electrolyte concentrations. A device model is developed to explain the characteristics of the ionic diode in more detail. In combination with experimental data, the model predicts that the ionic polarization diode has a delivery delay of 5 ms to reach physiologically relevant neurotransmitter concentrations at subcellular spatial resolution. The model further predicts that delays of amp;lt;1 ms can be reached by further miniaturization of the diode geometry. Altogether, the results show that ionic polarization diodes are a promising building block for the next generation of chemical neural interfaces.
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| 6. |
- Beech, Jason P., et al.
(författare)
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Active Posts in Deterministic Lateral Displacement Devices
- 2019
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Ingår i: Advanced Materials Technologies. - : Wiley. - 2365-709X. ; 4:9
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Tidskriftsartikel (refereegranskat)abstract
- Using electrically connected metal-coated posts in a deterministic lateral displacement (DLD) device and applying electric fields, electrokinetics is used to tune separations, significantly decrease the critical size for separation, and increase the dynamic range with switching times on the order of seconds. The strength of DLD stems from its binary behavior. To first approximation, particles move in one out of two trajectories based on their effective size. For particles that are close to the threshold size, a small external force is sufficient to nudge the particles from one trajectory to another. The devices consist of arrays of cylindrical metal-coated SU-8 posts connected by an underlying metal layer. This allows the application of voltages at the post surfaces and the generation of electric field gradients between neighboring posts, causing polarizable particles to experience a dielectrophoretic (DEP) force. This force, which depends on the volume and polarizability of the particle, can be made sufficient to push particles from one trajectory into another. In this way, the critical size in a device, normally fixed by the geometry, can be tuned. What's more, adding DEP in this way allows for the simultaneous creation of multiple size fractions.
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| 7. |
- Boda, Ulrika, et al.
(författare)
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Fully Screen-Printed Stretchable Organic Electrochemical Transistors
- 2023
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Ingår i: Advanced Materials Technologies. - : John Wiley and Sons Inc. - 2365-709X. ; :16
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Tidskriftsartikel (refereegranskat)abstract
- Stretchable organic electrochemical transistors (OECTs) are promising for wearable applications within biosensing, bio-signal recording, and addressing circuitry. Efficient large-scale fabrication of OECTs can be performed with printing methods but to date there are no reports on high-performance fully printed stretchable OECTs. Herein, this challenge is addressed by developing fully screen-printed stretchable OECTs based on an architecture that minimizes electrochemical side reactions and improves long-term stability. Fabrication of the OECTs is enabled by in-house development of three stretchable functional screen-printing inks and related printing processes. The stretchable OECTs show good characteristics in terms of transfer curves, output characteristics, and transient response up to 100% static strain and 500 strain cycles at 25% and 50% strain. The strain insensitivity of the OECTs can be further improved by strain conditioning, resulting in stable performance up to 50% strain. Finally, an electrochromic smart pixel is demonstrated by connecting a stretchable OECT to a stretchable electrochromic display. It is believed that the development of screen-printed stretchable electrochemical devices, and OECTs in particular, will pave the way for their use in wearable applications and commercial products. © 2023 The Authors.
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| 8. |
- Brooke, Robert, 1989-, et al.
(författare)
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Combining Vapor Phase Polymerization and Screen Printing for Printed Electronics on Flexible Substrates
- 2022
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Ingår i: Advanced Materials Technologies. - : John Wiley and Sons Inc. - 2365-709X. ; 7:7
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Tidskriftsartikel (refereegranskat)abstract
- Large area manufacturing of printed electronic components on ~A4-sized substrates is demonstrated by the combination of screen printing and vapor phase polymerization (VPP) into poly(3,4-ethylenedioxythiophene) (PEDOT). The oxidant layer required for the polymerization process is screen printed, and the resulting conductive polymer patterns are manufactured at high resolution (100 µm). Successful processing of several common oxidant species is demonstrated, and the thickness can be adjusted by altering the polymerization time. By comparing the polymer films of this work to a commercial PEDOT:PSS (PEDOT doped with poly(styrene sulfonate)) screen printing ink shows improved surface roughness (26 vs 69 nm), higher conductivity (500 vs 100 S cm–1) and better resolution (100 vs 200 µm). Organic electrochemical transistors, in which the transistor channel is polymerized into PEDOT through VPP, are also demonstrated to further emphasize on the applicability of this manufacturing approach. The resulting transistor devices are not only functional, they also show remarkable switching behavior with respect to ON current levels (–70 mA at –1 V), ON/OFF ratios (>105), switching times (tens of ms) and transconductance values (>100 mS) in standalone transistor devices, in addition to a high amplification factor (>30) upon integration into a screen printed inverter circuit. © 2022 The Authors.
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| 9. |
- Brooke, Robert, 1989-, et al.
(författare)
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Electrochromic Displays Manufactured by a Combination of Vapor Phase Polymerization and Screen Printing
- 2022
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Ingår i: Advanced Materials Technologies. - : John Wiley & Sons. - 2365-709X. ; 7:8
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Tidskriftsartikel (refereegranskat)abstract
- Smart label technology such as indicators is a growing field due to society's demand for Internet of Things devices. New materials and technologies are continuously being discovered and developed in order to provide better resolution, better performance, or more environmentally friendly devices. Within this report, screen printing technology is combined with vapor phase polymerization to synthesize three conductive polymers; poly(3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (PPy), and polythiophene (PTh). The conductive polymers are created in micrometer resolution and investigated for their electrochromic properties. PEDOT and PPy samples are combined into printed, laminated, transmissive electrochromic displays. The technology is further advanced to establish separate PEDOT, PPy, and PTh all-printed electrochromic displays using several screen printed layers. The PEDOT displays show improved color retention as compared to displays created with commercially available PEDOT:poly(styrene sulfonate) (PSS) with comparable contrast and switching behavior. All-printed PPy and PTh electrochromic displays with impressive electrochromic behavior are demonstrated. More complex patterns of 7-segment displays are created, thereby highlighting flexibility and individually switched sections of the conductive polymers. This research extends the screen printing and vapor phase polymerization combination to other conductive polymers and the potential commercialization of multicolor electrochromic displays that has been otherwise dominated by monochromatic PEDOT:PSS.
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| 10. |
- Cantoni, Federico, et al.
(författare)
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A perfusable multi-hydrogel vasculature on-chip engineered by 2-photon 3D printing and scaffold molding to improve microfabrication fidelity in hydrogels
- 2024
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Ingår i: Advanced Materials Technologies. - : John Wiley & Sons. - 2365-709X. ; 9:4
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Tidskriftsartikel (refereegranskat)abstract
- Engineering vasculature networks in physiologically relevant hydrogelsrepresents a challenge in terms of both fabrication, due to the cell–bioinkinteractions, as well as the subsequent hydrogel-device interfacing. Here, anew cell-friendly fabrication strategy is presented to realize perfusablemulti-hydrogel vasculature models supporting co-culture integrated in amicrofluidic chip. The system comprises two different hydrogels to specificallysupport the growth and proliferation of two different cell types selected for thevessel model. First, the channels are printed in a gelatin-based ink bytwo-photon polymerization (2PP) inside the microfluidic device. Then, ahuman lung fibroblast-laden fibrin hydrogel is injected to surround the printednetwork. Finally, human endothelial cells are seeded inside the printedchannels. The printing parameters and fibrin composition are optimized toreduce hydrogel swelling and ensure a stable model that can be perfused withcell media. Fabricating the hydrogel structure in two steps ensures that nocells are exposed to cytotoxic fabrication processes, while still obtaining highfidelity printing. In this work, the possibility to guide the endothelial cellinvasion through the 3D printed scaffold and perfusion of the co-culturemodel for 10 days is successfully demonstrated on a custom-made perfusionsystem.
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