High-Resolution Electrochemical Transistors Defined by Mold-Guided Drying of PEDOT:PSS Liquid Suspension

Abstract

Ion-sensitive transistors with nanoscale or microscale dimensions are promising for high-resolution electrophysiological recording and sensing. Technology that can pattern polymer functional materials directly from a solution can effectively avoid any chemical damage induced by conventional lithography techniques. The application of a mold-guided drying technique to pattern PEDOT:PSS-based transistors with high resolution directly from the water-based suspension is presented in this paper. Gold electrodes with short channels were first defined by creating high-resolution polymer lines with mold-guided drying followed by pattern transfer through a lift-off process. Then, PEDOT:PSS lines were subsequently created through an identical mold-guided drying process on the predefined electrodes. Small-scale transistor devices with both shortened channel length and width exhibited a good high-frequency response because of the weak capacitive effect. This is particularly advantageous for electrochemical transistors since the use of conventional fabrication techniques is extremely challenging in this case. In addition, modified polymer chain alignment of the assembled PEDOT:PSS lines during the drying process was observed by optical and electrical measurement. The mold-guided drying technique has been proven to be a promising method to fabricate small-scale devices, especially for biological applications.

Organic Electrochemical Transistors for In Vivo Bioelectronics

“…An interesting recent work by Li et al showed that the mold‐guided drying technique can be used to pattern PEDOT:PSS directly from its water suspension and fabricate OECTs with channels in the sub‐micrometer regime. [ 92 ] Similarly, other advanced patterning techniques (like e‐beam lithography) may be exploited to further shrink the size of OECTs. Reduction in the OECT device footprint will also be useful in monitoring the response of electrogenic tissues (such as cardiac or brain tissues) at the single‐cell level.…”

“…Reproduced with permission. [ 92 ] Copyright 2020, American Chemical Society. g) Illustration of OECT preparation using spray‐coating deposition.…”

Solvent-structured PEDOT:PSS surfaces: fabrication strategies and nanoscale properties

“…in turn, leading to boosted applications [28][29][30][31][32][33][34]. In this way, several groups have developed different nanostructured PEDOT:PSS surfaces by laser irradiation [27,31,33,35,36], nanoimprint lithography [25,29,37,38], and by using templates and molds [31,34,39].…”

“…in turn, leading to boosted applications [28][29][30][31][32][33][34]. In this way, several groups have developed different nanostructured PEDOT:PSS surfaces by laser irradiation [27,31,33,35,36], nanoimprint lithography [25,29,37,38], and by using templates and molds [31,34,39]. In these works, it was possible to fabricate distinct surface features as linear nanostructures or nanogratings [25,27,34,35,37,39], nanocavities [36],…”

Coagulation Bath‐Assisted 3D Printing of PEDOT:PSS with High Resolution and Strong Substrate Adhesion for Bioelectronic Devices

“…[1,2] In recent years it has been widely applied to applications in energy storage, [5] flexible electronics, [6] and recently bioelectronics [7] due to its high biocompatibility. Conventional manufacturing techniques such as ink-jet printing, [8,9] lithography, [10] electrochemical patterning, [11,12] aerosol printing [13,14] and screen printing [15,16] are common methods used to fabricate PEDOT:PSS-based electronic devices. [17] However, these methods normally have high processing complexity and often require cleanroom fabrication, which results in high-cost.…”