Neuromorphic pain perception and self-healing in an integrated electronic skin-bipolar synaptic transistor system

Inspired by the ability of synaptic transistors to mimic the signal transmission and plasticity regulation of synapses between human neurons, and the property of NiTi shape memory alloy (SMA) to recover its original shape after deformation upon heating, we propose a biomimetic system capable of sensing pain and recovering its original shape upon heating after deformation by external force. This system combines a polyvinylidene fluoride (PVDF) and NiTi SMA piezoelectric sensor and IGZO/Cu₂O bipolar synaptic transistor (BST). The sensor, composed of PVDF and NiTi SMA, converts external stress into electrical pulses. Applying these pulses to the gate of the BST simulates the complex behavior of synapses. The thermal response of the NiTi SMA enables autonomous repair at controlled temperatures, while BST responds to piezoelectric signals to simulate pain sensitization and obtains different current responses by adjusting the baseline of the gate voltage, thereby simulating pain sensation in different parts of the robotic skin. This work demonstrates the integration of pain perception, pain sensitization, and self-healing functions, providing a new avenue for the development of next-generation intelligent robotic skin.