Self-Adhesive,\nStretchable, and Thermosensitive Iontronic\nHydrogels for Highly Sensitive Neuromorphic Sensing–Synaptic\nSystems

Artificial\nsensory afferent nerves that emulate receptor nanochannel\nperception and synaptic ionic information processing in chemical environments\nare highly desirable for bioelectronics. However, challenges persist\nin achieving life-like nanoscale conformal contact, agile multimodal\nsensing response, and synaptic feedback with ions. Here, a precisely\ntuned phase transition poly(<i>N</i>-isopropylacrylamide)\n(PNIPAM) hydrogel is introduced through the water molecule reservoir\nstrategy. The resulting hydrogel with strongly cross-linked networks\nexhibits excellent mechanical performance (∼2000% elongation)\nand robust adhesive strength. Importantly, the hydrogel’s enhanced\nionic conductance and heterogeneous structure of the temperature-sensitive\ncomponent enable highly sensitive strain information perception (GF<sub>max</sub> = 7.94, response time ∼ 87 ms), temperature information\nperception (TCR<sub>max</sub> = −1.974%/°C, response time\n∼ 270 ms), and low energy consumption synaptic plasticity (42.2\nfJ/spike). As a demonstration, a neuromorphic sensing–synaptic\nsystem is constructed integrating iontronic strain/temperature sensors\nwith fiber synapses for real-time information sensing, discrimination,\nand feedback. This work holds enormous potential in bioinspired robotics\nand bioelectronics.