Programmable Doping-Enabled Engineering of Hydrogel Iontronics for Tailored Soft Ionic Devices

Soft ionic conductors with tunable mechanical properties and biological signal compatibility are essential for facilitating seamless abiotic-biotic interfaces. However, the lack of precise, scalable control over the intrinsic transport performance of these materials critically restricts their broader deployment in advanced biotechnology. In this work, we present a programmable doping strategy, inspired by conventional semiconductor manufacturing paradigms, aimed at creating high-performance hydrogel iontronic devices. By systematically modulating polyelectrolyte concentrations and strategically integrating lignosulfonate sodium, we meticulously tailor the semiconducting characteristics of hydrogel heterojunctions. The resulting programmable hydrogels exhibit exceptional operational tunability, successfully functioning as robust ionic diodes, logic circuits, pnp-type transistors, and synthetic synapses. This scalable method establishes a highly adaptable framework for tailored soft ionic conductors, broadening their potential applications in complex signal transmission and neuromorphic computing.