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

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Technology

Background:

• Conventional thermoelectric (TE) materials face limitations due to rigidity, toxicity, and poor recyclability.
• Developing flexible, non-toxic, and recyclable TE materials is crucial for advanced applications.

Purpose of the Study:

• To introduce a novel ionic TE hydrogel with enhanced mechanical and environmental properties.
• To demonstrate the hydrogel's potential for dual-mode sensing and its alignment with circular economy principles.

Main Methods:

• Synthesis of an ionic thermoelectric hydrogel.
• Characterization of mechanical stretchability (1400% strain), optical transparency (98%), electrical conductivity (1.9 mS cm⁻¹), and Seebeck coefficient (-1.05 mV/K).
• Fabrication of dual-mode sensing devices using recyclable polyurethane encapsulation.

Main Results:

• The hydrogel exhibits exceptional stretchability, transparency, and electrical properties.
• Recyclable devices enabled stable simultaneous temperature and pressure sensing via TE and triboelectric effects.
• The material maintained 96% performance after recycling and self-healing cycles.

Conclusions:

• The developed ionic TE hydrogel offers a sustainable alternative to conventional TE materials.
• The hydrogel-based devices support efficient dual-mode sensing and are suitable for eco-friendly human-machine interfaces.
• This work promotes circular economy principles in advanced material design.