Biodegradable and flexible artificial nociceptor based on Mg/MgO threshold switching memristor

As an important receptor located in the skin, a nociceptor is capable of detecting noxious stimuli and sending warning signals to the central nervous system to avoid tissue damage, thus inspiring the development of artificial nociceptors for electronic receptors. Recently, memristors have attracted increasing attention for developing artificial nociceptors due to the simplicity of the artificial nociceptive system. However, the realization of artificial nociceptors with biocompatibility and biodegradability in a single memristive device remains a challenge. Herein, a fully biocompatible and biodegradable threshold switching (TS) memristor consisting of W/MgO/Mg/W configuration was proposed as an artificial nociceptor. The device showed unidirectional TS characteristics with stable electrical performance under bending conditions. Critical nociceptor behaviors, including threshold, relaxation, no adaptation, allodynia, and hyperalgesia, were successfully demonstrated in the memristive nociceptor. Meanwhile, an optoelectronic nociceptor system was built by the integration of a photoresistor and the memristor. Importantly, the devices transferred on a biodegradable polyvinyl acetate substrate as physically transient electronics could completely dissolve in deionized water, simulating the decomposition of skin necrosis. This study provides a novel route toward developing fully biocompatible and biodegradable artificial nociceptors for promising applications in implantable and wearable electronics and secure bio-integrated systems.