Retinoic Acid-Poly(lactic) Acid Composite for Biocompatible Optoelectronic Synapses with Flexible Curvature Detection and Biomimetic Imprinting Capabilities

Emerging biocompatible artificial synapses show promise for bioelectronics but face challenges in high voltage requirements and functionality due to limited research on bioderived materials. This study introduces a pioneering biocompatible optoelectronic synapse utilizing poly(lactic) acid (PLA) and retinoic acid (RA), addressing the scarcity of research on bioderived materials for artificial optoelectronic synapses. The device showcases flexibility in curvature sensing and bioimprinting, operating at low voltages (10 mV), and consuming minimal power (60 fJ), thereby emulating natural neural synapse functions. It also adheres to the human skin, detecting minor body curvature changes. The operation mechanism is analyzed through molecular polarization and band theory. A 12 × 12 array built on this technology demonstrates capabilities in image recognition and information storage, notably replicating biological imprinting behaviors for the first time. These findings open new pathways for developing fully biocompatible, low-power optoelectronic synapses, expanding their potential in wearable and implantable bioelectronics.