Flexible metal oxide synaptic transistors using biomass-based hydrogel as gate dielectric

Abstract

The construction of devices with biocompatible and biodegradable materials is a sustainable approach which will open up a new way for the development of green electronics in the future. Compared with organic materials, inorganic materials are more suitable candidates for the fabrication of synaptic transistors due to their better environmental stability, higher mobility and less toxicity. However, the majority of gate electrolytes used in the reported synaptic transistors were non-biocompatible or non-biodegradable. Herein, for the first time, we sputtered inorganic metal oxide indium tin oxide (ITO) on biomass-based hydrogel for the fabrication of synaptic devices, which showed good current on/off ratio (>105). Moreover, several vital synaptic behaviors were successfully simulated in pair such as excitatory post-synaptic current, inhibitory post-synaptic current, paired pulse facilitation, paired-pulse depression and short-term memory to long-term memory. High-pass filter and Pavlov associative learning and oblivion, two kinds of advanced simulation behaviors, were mimicked respectively. Finally, synaptic transistors were fabricated on flexible PET substrates with ITO electrodes and exhibited good mechanical stability under the bending tests. In conclusion, this work provides a unique example for the sustainable development of green neuromorphic electronics.