Electrical Current Modulation in Wood Electrochemical Transistor

The nature of mass transport in plants has recently inspired the development of low-cost and sustainable wood-based electronics. Herein, we report a wood electrochemical transistor (WECT) where all three electrodes are fully made of conductive wood. The conductive wood is prepared using a two-step strategy of wood delignification followed by wood amalgamation with a mixed electron-ion conducting polymer, poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS). The modified wood has an electrical conductivity of up to 69 Sm-1 induced by the formation of PEDOT:PSS microstructures inside the wood 3D scaffold. Conductive wood is then used to fabricate the WECT, which is capable of modulating an electrical current in a porous and thick transistor channel (1 mm) with an on/off ratio of 50. The device shows a good response to gate voltage modulation and exhibits dynamic switching properties similar to those of an organic electrochemical transistor (OECT). This wood-based device and the proposed working principle demonstrate the possibility to incorporate active electronic functionality into the wood, suggesting different types of bio-based electronic devices

植物体内物质输运的本质，近来为低成本、可持续的木质电子器件研发提供了重要灵感。本研究报道了一款木质电化学晶体管（wood electrochemical transistor, WECT），其三个电极均完全由导电木材制备而成。导电木材的制备采用两步法：先对木材进行脱木质素处理，随后将其与电子-离子混合导电聚合物聚(3,4-乙撑二氧噻吩)-聚苯乙烯磺酸盐（poly(3,4-ethylenedioxythiophene)polystyrene sulfonate, PEDOT:PSS）进行浸渍复合。经改性后的木材三维多孔骨架内部可形成PEDOT:PSS微观结构，其电导率最高可达69 S·m⁻¹。随后利用导电木材制备得到该WECT器件，其可对厚度为1 mm的多孔厚晶体管沟道内的电流进行调控，开关比达50。该器件对栅极电压调控表现出良好响应，动态开关特性与有机电化学晶体管（organic electrochemical transistor, OECT）相近。这款木质器件及其提出的工作原理，证实了将有源电子功能集成于木材中的可行性，为各类生物基电子器件的开发提供了新的可能。