Stable Synapse Function of Bilayer Stretchable Memristor via Atomic Layer Deposition

This study develops one Al₂O₃/HfO₂-based stretchable memristor with discrete structure (D-HAP) using photolithography and thermal atomic layer deposition (TALD), which can withstand a 30% stretch strain for 500 consecutive stretch-release cycles, exhibiting stable resistive switching with a ON/OFF ratio exceeding 10³. Stable electrical performance under stretch conditions is attributed to the PDMS/Au substrate with a wrinkled structure and the unique discrete structure featuring a PDMS buffer layer. The former enhances the fracture elongation of the Au electrodes, while the latter reduces stress concentration in the discrete units, thereby improving the device's strain tolerance. Additionally, D-HAP memristor demonstrate artificial synapse capabilities, successfully emulating synaptic behaviors under stretching. Moreover, the triple spike time-dependent plasticity of D-HAP memristor is harnessed to implement the Bienenstock-Cooper-Munro (BCM) learning rule. This work provides a novel approach for designing stretchable memristor with stable storage and computational ability under dynamic conditions.