A Fingertip-Mimicking 12×16 200μm-Resolution e-skin Taxel Readout Chip with per-Taxel Spiking Readout and Embedded Receptive Field Processing

This work describes an electronic skin (e-skin) taxel readout chip in 0.18 μ m CMOS technology, achieving the highest reported spatial resolution of 200 μ m, comparable to human fingertips. A key innovation is the integration on chip of a12 × 16 taxel array with per-taxel signal conditioning frontend and spiking readout combined with embedded neuromorphic first-order processing through Complex Receptive Fields (CRFs). The chip has been designed to incorporate a polyvinylidene fluoride (PVDF)-based piezoelectric sensor layer. Experimental results show that Spiking Neural Network (SNN)-based classification of the chip's spatiotemporal spiking output for input tactile stimuli such as texture and flutter frequency achieves excellent accuracies up to 97.1% and 99.2% of classification accuracy, respectively. This is despite using only a small 256-neuron SNN classifier, a low equivalent spike encoding resolution of 3-4 bits, a sub-Nyquist 2.2kHz population spiking rate, and a state-of-the-art per-taxel (12.33nW) and system (75 μ W -5mW) power consumption.