Vapor‐Coated Monofilament Fibers for Embroidered Electrochemical Transistor Arrays on Fabrics

Abstract

AbstractFiber‐based electrochemical transistors can be embroidered onto fabrics for wearable and implantable bioelectronics. However, the active channel length of known fiber‐based electrochemical transistors is defined by the dynamic contact area between the conductive fiber and a liquid electrolyte, meaning that existing iterations cannot be reliably operated upon immersion in biological media. A proof‐of‐concept parallel‐junction electrochemical transistor on a silk fabric with a fixed, micrometer‐sized channel length that is independent of electrolyte contact area is reported. A high on/off ratio of 1000, and notable transconductance value of 100 µS at zero gate voltage and low applied drain bias (0.7 V) is obtained, making this device amenable to subsequent incorporation into low‐power‐consuming integrated circuits. Large‐area arrays of this transistor can be rapidly created by straight‐stitching a monofilament fiber channel onto a fabric substrate, meaning that simple embroidery approaches can be used to fabricate spatially resolved electrode arrays for electrophysiological applications.