Work

Non-hazardous and fully recyclable ionic thermoelectrics for sustainable human–machine interfaces

Year: 2025

Type: article

Abstract: Thermoelectric (TE) materials directly convert temperature gradients into electrical potential. However, conventional rigid TE materials are limited by poor mechanical compliance, potential toxicity, and non-recyclability. Here, we present an ionic TE hydrogel that addresses these challenges through high stretchability, full recyclability, and non-toxic composition. The hydrogel can be recycled through an environmentally friendly process that generates no hazardous byproducts. Our material exhibits exceptional mechanical stretchability with 1400% strain capacity, 98% optical transparency, high electrical conductivity (1.9 mS cm-1), and a Seebeck coefficient (−1.05 mV/K). When encapsulated in recyclable polyurethane, the resulting devices enable stable dual-mode sensing through both TE and triboelectric mechanisms, allowing simultaneous temperature and pressure detection without complex signal processing. The devices maintain 96% of their electrical performance even after recycling and self-healing cycles. This innovative hydrogel design strategy aligns with circular economy principles for environment-friendly human-machine interface applications. Thermoelectric materials can convert temperature gradients into electrical potential; however, traditional materials have unfavorable mechanical, optical, and electrical properties for devices. Here, the authors design an ionic hydrogel system optimizing these properties for human-machine interface devices.

Source: Nature Communications

DOI: 10.1038/s41467-025-65377-9