| 1. |
- Arbring Sjöström, Theresia, et al.
(författare)
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Cross-Linked Polyelectrolyte for Improved Selectivity and Processability of lontronic Systems
- 2017
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Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 9:36, s. 30247-30252
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Tidskriftsartikel (refereegranskat)abstract
- On-demand local release of biomolecules enables fine-tuned stimulation for the next generation of neuromodulation therapies. Such chemical stimulation is achievable using iontronic devices based on microfabricated, highly selective ion exchange membranes (IEMs). Current limitations in processability and performance of thin film LEMs hamper future developments of this technology. Here we address this limitation by developing a cationic IEM with excellent processability and ionic selectivity: poly(4-styrenesulfonic acidco-maleic acid) (PSS-co-MA) cross-linked with polyethylene glycol (PEG). This enables new design opportunities and provides enhanced compatibility with in vitro cell studies. PSSA-co-MA/PEG is shown to out-perform the cation selectivity of the previously used iontronic material.
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| 2. |
- Fabiano, Simone, et al.
(författare)
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Ferroelectric polarization induces electronic nonlinearity in ion-doped conducting polymers
- 2017
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Ingår i: Science Advances. - : American Association for the Advancement of Science. - 2375-2548. ; 3:6
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Tidskriftsartikel (refereegranskat)abstract
- Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is an organic mixed ion-electron conducting polymer. The PEDOT phase transports holes and is redox-active, whereas the PSS phase transports ions. When PEDOT is redox-switched between its semiconducting and conducting state, the electronic and optical properties of its bulk are controlled. Therefore, it is appealing to use this transition in electrochemical devices and to integrate those into large-scale circuits, such as display or memory matrices. Addressability and memory functionality of individual devices, within these matrices, are typically achieved by nonlinear current-voltage characteristics and bistability—functions that can potentially be offered by the semiconductor-conductor transition of redox polymers. However, low conductivity of the semiconducting state and poor bistability, due to self-discharge, make fast operation and memory retention impossible. We report that a ferroelectric polymer layer, coated along the counter electrode, can control the redox state of PEDOT. The polarization switching characteristics of the ferroelectric polymer, which take place as the coercive field is overcome, introduce desired nonlinearity and bistability in devices that maintain PEDOT in its highly conducting and fast-operating regime. Memory functionality and addressability are demonstrated in ferro-electrochromic display pixels and ferro-electrochemical transistors.
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| 3. |
- Jonsson, Amanda, et al.
(författare)
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Bioelectronic neural pixel: Chemical stimulation and electrical sensing at the same site
- 2016
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 113:34, s. 9440-9445
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Tidskriftsartikel (refereegranskat)abstract
- Local control of neuronal activity is central to many therapeutic strategies aiming to treat neurological disorders. Arguably, the best solution would make use of endogenous highly localized and specialized regulatory mechanisms of neuronal activity, and an ideal therapeutic technology should sense activity and deliver endogenous molecules at the same site for the most efficient feedback regulation. Here, we address this challenge with an organic electronic multifunctional device that is capable of chemical stimulation and electrical sensing at the same site, at the single-cell scale. Conducting polymer electrodes recorded epileptiform discharges induced in mouse hippocampal preparation. The inhibitory neurotransmitter, γ-aminobutyric acid (GABA), was then actively delivered through the recording electrodes via organic electronic ion pump technology. GABA delivery stopped epileptiform activity, recorded simultaneously and colocally. This multifunctional “neural pixel” creates a range of opportunities, including implantable therapeutic devices with automated feedback, where locally recorded signals regulate local release of specific therapeutic agents.
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| 4. |
- Kergoat, Loig, et al.
(författare)
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A Water-Gate Organic Field-Effect Transistor
- 2010
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Ingår i: Advanced Materials. - : John Wiley and Sons, Ltd. - 0935-9648 .- 1521-4095. ; 22:23, s. 2565-2569
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Tidskriftsartikel (refereegranskat)abstract
- High-dielectric-constant insulators, organic monolayers, and electrolytes have been successfully used to generate organic field-effect transistors operating at low voltages. Here, we report on a device gated with pure water. By replacing the gate dielectric by a simple water droplet, we produce a transistor that entirely operates in the field-effect mode of operation at voltages lower than 1V. This result creates opportunities for sensor applications using water-gated devices as transducing medium.
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| 5. |
- Kergoat, Loig, et al.
(författare)
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Advances in organic transistor-based biosensors : from organic electrochemical transistors to electrolyte-gated organic field-effect transistors.
- 2012
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer. - 1618-2642 .- 1618-2650. ; 402:5, s. 1813-1826
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Forskningsöversikt (refereegranskat)abstract
- Organic electronics have, over the past two decades, developed into an exciting area of research and technology to replace classic inorganic semiconductors. Organic photovoltaics, light-emitting diodes, and thin-film transistors are already well developed and are currently being commercialized for a variety of applications. More recently, organic transistors have found new applications in the field of biosensors. The progress made in this direction is the topic of this review. Various configurations are presented, with their detection principle, and illustrated by examples from the literature.
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| 6. |
- Kergoat, Loig, et al.
(författare)
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Detection of Glutamate and Acetylcholine with Organic Electrochemical Transistors Based on Conducting Polymer/Platinum Nanoparticle Composites
- 2014
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Ingår i: Advanced Materials. - : Wiley-VCH Verlag. - 0935-9648 .- 1521-4095. ; 26:32, s. 5658-5664
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study is to open a new scope for organic electrochemical transistors based on PEDOT:PSS, a material blend known for its stability and reliability. These devices can leverage molecular electrocatalysis by incorporating small amounts of nano-catalyst during the transistor manufacturing (spin coating). This methodology is very simple to implement using the know-how of nanochemistry and results in efficient enzymatic activity transduction, in this case utilizing choline oxidase and glutamate oxidase.
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| 7. |
- Kergoat, Loig, 1984-, et al.
(författare)
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DNA detection with a water-gated organic field-effect transistor
- 2012
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Ingår i: Organic electronics. - : Elsevier. - 1566-1199 .- 1878-5530. ; 13:1, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- A DNA sensor based on a water-gated organic field-effect transistor is described. The semiconductor is poly [3-(5-carboxypentyl)thiophene-2,5-diyl] onto which DNA probes are covalently grafted via NHS/EDC chemistry. Clear changes in the output characteristic of the device are observed upon DNA immobilization and after DNA hybridization. Experimental data point out the importance of the electrolyte Debye length that can screen negative DNA charges and impede transduction. For this reason, deionized water was used in order to increase the Debye length up to several hundreds of nanometers. In this case, a decrease in the off current was observed upon hybridization, whereas no significant change occurred when using saline solutions.
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| 8. |
- Kergoat, Loig, et al.
(författare)
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Tuning the threshold voltage in electrolyte-gated organic field-effect transistors
- 2012
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 109:22, s. 8394-8399
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Tidskriftsartikel (refereegranskat)abstract
- Low-voltage organic field-effect transistors (OFETs) promise for low power consumption logic circuits. To enhance the efficiency of the logic circuits, the control of the threshold voltage of the transistors are based on is crucial. We report the systematic control of the threshold voltage of electrolyte-gated OFETs by using various gate metals. The influence of the work function of the metal is investigated in metal-electrolyte-organic semiconductor diodes and electrolyte-gated OFETs. A good correlation is found between the flat-band potential and the threshold voltage. The possibility to tune the threshold voltage over half the potential range applied and to obtain depletion-like (positive threshold voltage) and enhancement (negative threshold voltage) transistors is of great interest when integrating these transistors in logic circuits. The combination of a depletion-like and enhancement transistor leads to a clear improvement of the noise margins in depleted-load unipolar inverters.
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| 9. |
- Mitraka, Evangelia, et al.
(författare)
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Solution processed liquid metal-conducting polymer hybrid thin films as electrochemical pH-threshold indicators
- 2015
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Ingår i: Journal of Materials Chemistry C. - : Royal Society of Chemistry. - 2050-7526 .- 2050-7534. ; 3:29, s. 7604-7611
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Tidskriftsartikel (refereegranskat)abstract
- A global and accurate mapping of the environment could be achieved if sensors and indicators are mass-produced at low cost. Printed electronics using polymeric (semi) conductors offer a platform for such sensor/indicator based circuits. Herein, we present the material concept for an electrochemical pH-threshold indicator based on a printable hybrid electrode which comprises a liquid metal alloy (GaInSn) embedded in a conducting polymer matrix (PEDOT). This hybrid electrode displays a large variation in open circuit potential versus pH in an electrochemical cell, which when connected to the gate of an electrochemical transistor leads to a dramatic change in the drain current in a narrow range of pH.
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| 10. |
- Sinno, Hiam, 1983-, et al.
(författare)
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Bias stress effect in inverters based on polyelectrolyte-gated organic field effect transistors
- 2013
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Prolonged gate bias application causes undesirable operational instabilities in organic transistors involving threshold voltage shift and drain current degradation; an effect known as bias stress. In this paper, we report how this instability is manifested in inverter circuits based on polyelectrolytegated p-type organic field effect transistors (EGOFETs) operating at low voltage. We find that bias stress causes a significant, but recoverable, shift in inverter switching threshold voltage. Measurements with two different polyelectrolytes reveal significant differences in the stressing and recovery behaviour, which is ascribed to the distinct nature of the ion conductive groups in the polyelectrolyte. Moreover, we report a large influence of illumination on the recovery process for one of the polyelectrolytes but not for the other, which demonstrates the need to characterize bias stress behavior for each new materials combination.
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