Lead-Free Halide Perovskite-Based Flexible Memristor for an Artificial Mechano-nociceptive System

Herein, novel lead-free Cs₃Bi₂I₉ nanocrystals (NCs) were preferred through first-principles calculations and crystal orbital Hamilton population (COHP). An artificial nociceptor was designed using the lead-free halide perovskite (HP) Cs₃Bi₂I₉ NCs doped into poly(methyl methacrylate) (PMMA). The resulting composite material memristor demonstrated remarkable resistive switching performance through conductive atomic force microscopy (C-AFM). PMMA&Cs₃Bi₂I₉-based memristors show an ultrafast switching speed of 30 ns and low threshold voltage of ≈0.6 V with little variation, which were attributed to the synergistic effect of the active metal electrodes and halide vacancy conductive filaments. Impressively, the memristors show high mechanical bending stability (bending times = 1000) and still exhibit excellent resistance state (RS) properties and multilevel storage after 30 days exposed to ambient conditions. More importantly, the fundamental nociceptive functions were fully demonstrated. Furthermore, a mechano-nociceptor system was designed to simulate the mechanism of biological pain perception, which could selectively react to mild and harmful stimuli. Our study provides new strategies for developing efficient neuromorphic materials and devices.