Electrical current modulation in wood electrochemical transistor

Abstract

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 (CW). The CW 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. CW 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. 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.

Impact of doping on the mechanical properties of conjugated polymers

“…For instance, OECTs with a channel thickness of 1 mm could be created by dyeing the internal cell walls of balsa wood with PEDOT:PSS, which enabled ingression of the electrolyte and hence relatively fast switching on the order of a few seconds. 183 Another approach is the use of non-planar architectures such as filaments. For example, oriented PEDOT:PSS microfibers with an E of up to 4 GPa have been used as the channel, yielding OECTs with a record device performance thanks to a very high μ of up to 13 cm 2 V −1 s −1 .…”