Flexible Dual-Gate MoS₂ Neuromorphic Transistors on Freestanding Proton-Conducting Chitosan Membranes

Flexible neuromorphic devices are highly desirable for emerging perception and sensing systems. Here, multiterminal neuromorphic devices based on freestanding dual-gate MoS
₂
transistors on freestanding proton-conducting chitosan membranes are proposed. The chitosan membranes are simultaneously used as the dielectrics and substrates. By replicating the surface of silicon substrate, the roughness of chitosan substrate is successfully reduced from 11 to 1.7 nm. Besides, the membranes show a large specific in-plane electric-double-layer capacitance of 1.3 μF/cm
²
at 1.0 Hz when the interelectrode space is 100 μm. The dual-gate MoS
₂
transistors exhibit high mechanical stability and electrical performance on flexible chitosan membranes. Some important synaptic functions, such as paired-pulse facilitation, and tunable high pass filter, are successfully emulated. Furthermore, spatiotemporal dynamic correlation is also experimentally demonstrated. Our results will greatly enrich the intension of 2-D flexible electronics and neuromorphic perception and sensing systems.