Mechanotransducing Organic Electrochemical Diode for Crosstalk-Inhibited Artificial Skin

Abstract

High-resolution deformable artificial skin emulating human tactility is critical for interactive robotics, advanced prosthetics, and wearable electronics. While recent developments using stretchable transistors and diodes have shown progress in resolving electrical crosstalk between the pixels, persistent challenges remain to simultaneously satisfy large deformability, simple device structure, easy scalable fabrication, and analog tactile signal fidelity under dynamic stimuli. This work unifies the deformable ionic diode function and mechanotransduction in an organic electrochemical diode film. The diode operates through ion-hole coupling dynamics at the organic semiconductor-electrolyte interface, in which mechanical deformation induces reversible changes in impedance while maintaining the rectifying performance. Key achievements include large rectification ratios (5 × 102) of the diode at high measurement frequencies (102 Hz) – surpassing the reported ionic diodes by more than an order of magnitude in both the rectification ratio and frequency – alongside its robust performance stability under repeated stretch cycles. This unified operational mode enables direct fabrication of crosstalk-resistant ion-electronic skin (IE-skin) arrays by the conventional printing techniques, achieving accurate strain/pressure mapping without additional signal processing. This innovative concept of unifying the advanced ionic diode and mechanotransduction establishes a new material design paradigm for soft smart sensory systems and adaptive deformable electronics.