Transparent microelectrodes that facilitate simultaneous optical and electrophysiological interfacing are desirable tools for neuroscience. Electrodes made from transparent conductors such as graphene and indium tin oxide (ITO) show promise but are often limited by poor interfacial charge-transfer properties. Here, microelectrodes are demonstrated that take advantage of the transparency and volumetric capacitance of the mixed ion-electron conductor Poly(3,4- ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). Ring-shaped microelectrodes are fabricated by inkjet-printing PEDOT:PSS, encapsulating with Parylene-C, and then exposing a contact site that is much smaller than the microelectrode outer diameter. This unique structure allows the encapsulated portion of the microelectrode volume surrounding the contact site to participate in signal transduction, which reduces impedance and enhances charge storage capacity. While using the same 100 μm diameter contact site, increasing the outer diameter of the encapsulated electrode from 300 to 550 μm reduces the impedance from 294±21 to 98±2 kΩ, respectively, at 1 Hz. Similarly, the charge storage capacity is enhanced from 6 to 21 mC cm-2. The PEDOT:PSS microelectrodes provide a low-haze, high-transmittance optical interface, demonstrating their suitability for optical neuroscience applications. They remain functional after a million 1 V stimulation cycles, up to 600 μA of stimulation current, and more than 1000 mechanical bending cycles.
透明微电极,促进同时光学和电生理接口是理想的工具神经科学。由透明导体(如石墨烯和氧化铟锡(ITO))制成的电极显示出前景,但往往受到界面电荷转移性能差的限制。本研究展示了利用混合离子电子导体聚(3,4-乙烯二氧噻吩)聚苯乙烯磺酸盐(PEDOT:PSS)的透明度和容量电容的微电极。通过喷墨打印PEDOT:PSS制备环形微电极,用聚苯乙烯- c封装,然后暴露出比微电极外径小得多的接触点。这种独特的结构允许围绕接触部位的微电极体积的封装部分参与信号转导,从而降低阻抗并增强电荷存储容量。当接触点直径为100 μm时,将封装电极外径从300 μm增加到550 μm,在1hz时阻抗分别从294±21降低到98±2 kΩ。同样,电荷存储容量从6增加到21 mC cm-2。PEDOT:PSS微电极提供了低雾霾、高透射率的光学接口,证明了它们在光学神经科学应用中的适用性。在100万次1 V的刺激循环、高达600 μA的刺激电流和1000多次机械弯曲循环后,它们仍能保持功能。
{"title":"Transparent, Low-Impedance Inkjet-Printed PEDOT:PSS Microelectrodes for Multi-modal Neuroscience.","authors":"Preston D Donaldson, Sarah L Swisher","doi":"10.1002/pssa.202100683","DOIUrl":"https://doi.org/10.1002/pssa.202100683","url":null,"abstract":"<p><p>Transparent microelectrodes that facilitate simultaneous optical and electrophysiological interfacing are desirable tools for neuroscience. Electrodes made from transparent conductors such as graphene and indium tin oxide (ITO) show promise but are often limited by poor interfacial charge-transfer properties. Here, microelectrodes are demonstrated that take advantage of the transparency and volumetric capacitance of the mixed ion-electron conductor Poly(3,4- ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). Ring-shaped microelectrodes are fabricated by inkjet-printing PEDOT:PSS, encapsulating with Parylene-C, and then exposing a contact site that is much smaller than the microelectrode outer diameter. This unique structure allows the encapsulated portion of the microelectrode volume surrounding the contact site to participate in signal transduction, which reduces impedance and enhances charge storage capacity. While using the same 100 μm diameter contact site, increasing the outer diameter of the encapsulated electrode from 300 to 550 μm reduces the impedance from 294±21 to 98±2 kΩ, respectively, at 1 Hz. Similarly, the charge storage capacity is enhanced from 6 to 21 mC cm<sup>-2</sup>. The PEDOT:PSS microelectrodes provide a low-haze, high-transmittance optical interface, demonstrating their suitability for optical neuroscience applications. They remain functional after a million 1 V stimulation cycles, up to 600 μA of stimulation current, and more than 1000 mechanical bending cycles.</p>","PeriodicalId":74443,"journal":{"name":"Physica status solidi. A, Applications and materials science : PSS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10461862/pdf/nihms-1784500.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10114187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}