A versatile sustainable biosubstrate stabilizing metal conductors for soft sensors

Abstract

In soft electronics, metal-on-polymer soft sensors serve as the critical interface between physical stimuli and electronic signals. However, the growing environmental burden of electronic waste, together with limited material durability, underscores the urgent need for substrate materials that can address sustainability challenges at both ecological and performance levels. Existing petroleum-derived substrates lack self-repairability, suffer from interfacial instability and pose persistent environmental concerns due to their non-recyclable nature. Here we develop an intrinsically dynamic biosubstrate prepared by melt polymerization of naturally sourced phytic acid and lipoic acid. The synergistic interplay of disulfide, ester and hydrogen-bonding networks provide desirable mechanical properties, self-repairability and thermally enhanced self-adhesion, ensuring stable metal–substrate interfacial integrity. In addition, the material enables degradability and closed-loop recyclability. The intrinsically dynamic biosubstrate demonstrates broad applicability in metal-on-polymer soft sensors, supporting remote sensing and biosignal acquisition under repeated deformation, structural damage and continuous friction. Overall, intrinsically dynamic biosubstrate redefines the role of substrates in soft sensors, transforming them from conventionally passive support layers to key performance-driving components, while enabling sustainable end-of-life management through facile device disassembly and recyclability. The growing market for soft electronics largely relies on fossil fuel-based polymer substrates. This work points towards a more sustainable future for the field by presenting a bio-based substrate for metal-on-polymer soft sensors that are degradable, recyclable, interfacially robust, mechanically tough and self-reparable.