Artificial Somatosensors: Feedback Receptors for Electronic Skins

Abstract

The human skin is the largest sensory organ, made up of complex sensors that detect noxious stimuli to rapidly send warning signals to the central nervous system to initiate a motor response. It is complex to mimic key skin features using existing tactile sensors, and there exists no somatosensor that responds to real stimuli of pressure, temperature, and touch. Herein, three critical skin receptors created by realizing integrated electronic systems that mimic the feedback response of somatosensors are experimentally demonstrated. Fully functional Pacinian corpuscles, thermoreceptors, and nociceptors are realized using a combination of stretchable pressure sensors, phase‐change oxide thin films, and threshold‐based resistive switching (memristor) memory elements. The ability to detect and respond to pressure, temperature, and pain stimuli above a threshold with real‐life performance characteristics is demonstrated with explanation of underlying mechanisms. The ability to design and realize artificial skin receptors enables replacement of affected human skin regions, augment skin sensitivity for agile applications in defense and sports, and drive advancements in intelligent robotics.

A biopolymer-gated ionotronic junctionless oxide transistor array for spatiotemporal pain-perception emulation in nociceptor network

“…There are a wide variety of pain receptors in the epidermis. [8][9][10][11] These nociceptors are only evoked when a harmful stimulus exceeds a certain value that could potentially injure tissues, such as extreme temperature, large mechanical stress, the presence of undesirable chemical molecules, etc. [12][13][14] Acting as a threshold switch, this network that consists of peripheral stimulated nociceptors not only selectively provides a rapid warning to the CNS but also contributes to a motor response to avoid imminent threat or injury from the environment.…”

Artificial Adaptive and Maladaptive Sensory Receptors Based on a Surface‐Dominated Diffusive Memristor

“…Bioinspired electronics are technologies that mimic the sensory transduction of biological receptors from an external stimulus to an electrical signal, signal transmission of biological neurons, and synaptic plasticity. [ 11 , 12 , 13 , 14 , 15 , 16 ] A memristor has successfully demonstrated the potential to mimic leaky integrate‐and‐firing (LIF) [ 17 ] in biological neurons and synaptic functions including the transformation of short‐term plasticity to long‐term plasticity, [ 18 , 19 ] spick‐timing‐dependent plasticity, and spick‐rate‐dependent plasticity. [ 20 , 21 ] Although these qualitative functionalities of the neuron and synapse may represent significant steps toward the realization of bioinspired electronics, electronic sensory receptors with all features of threshold, adaptation, and maladaptation functions have not yet been implemented.…”

Electronic skin: from flexibility to a sense of touch

“…Last year, Bhaskaran and her colleagues produced a material that can mimic the skin's response to excessive heat, pressure and pain, as well as the brain's reaction to it 12 . They combined a flexible gold-PDMS pressure sensor with a vanadium oxide temperature sensor and a component based on strontium oxide that 'remembers' how much electrical charge has flowed through it, called a memristor.…”