A Bioinspired Artificial Injury Response System Based on a Robust Polymer Memristor to Mimic a Sense of Pain, Sign of Injury, and Healing

Flexible electronic skin with features that include sensing, processing, and responding to stimuli have transformed human-robot interactions. However, more advanced capabilities, such as human-like self-protection modalities with a sense of pain, sign of injury, and healing, are more challenging. Herein, a novel, flexible, and robust diffusive memristor based on a copolymer of chlorotrifluoroethylene and vinylidene fluoride (FK-800) as an artificial nociceptor (pain sensor) is reported. Devices composed of Ag/FK-800/Pt have outstanding switching endurance >10(6) cycles, orders of magnitude higher than any other two-terminal polymer/organic memristors in literature (typically 10(2)-10(3) cycles). In situ conductive atomic force microscopy is employed to dynamically switch individual filaments, which demonstrates that conductive filaments correlate with polymer grain boundaries and FK-800 has superior morphological stability under repeated switching cycles. It is hypothesized that the high thermal stability and high elasticity of FK-800 contribute to the stability under local Joule heating associated with electrical switching. To mimic biological nociceptors, four signature nociceptive characteristics are demonstrated: threshold triggering, no adaptation, relaxation, and sensitization. Lastly, by integrating a triboelectric generator (artificial mechanoreceptor), memristor (artificial nociceptor), and light emitting diode (artificial bruise), the first bioinspired injury response system capable of sensing pain, showing signs of injury, and healing, is demonstrated.

Automated summary

This study presents a flexible and robust diffusive memristor as an artificial nociceptor (pain sensor) based on a copolymer of chlorotrifluoroethylene and vinylidene fluoride. The device exhibits outstanding switching endurance and in situ conductive atomic force microscopy is employed to dynamically switch individual filaments. It is hypothesized that the high thermal stability and high elasticity of the copolymer contribute to its superior morphological stability. The integration of different components results in the demonstration of a bioinspired injury response system capable of sensing pain, showing signs of injury, and healing.