Soft and Stretchable Thermoelectric Generators Enabled by Liquid Metal Elastomer Composites

Area of Science:

• Materials Science
• Energy Harvesting
• Wearable Technology

Background:

• Stretchable thermoelectric generators (TEGs) are crucial for battery-free wearable electronics, but require advanced soft conductive materials for effective heat absorption and power generation.
• Current limitations involve integrating robust electrical wiring and thermal management within flexible systems that conform to the body.

Purpose of the Study:

• To develop a highly stretchable thermoelectric generator (TEG) architecture for efficient energy harvesting from body heat.
• To integrate soft conductive materials for improved thermal management and electrical connectivity in wearable applications.

Main Methods:

• Fabrication of a soft-matter TEG using liquid metal embedded elastomer (LMEE) composites.
• Integration of n-type and p-type Bi2Te3 semiconductor arrays within the LMEE matrix.
• Testing of device performance under various temperature gradients and mechanical strain.

Main Results:

• The developed TEG architecture seamlessly integrates 100 thermoelectric semiconductor elements in a compact 41.0 × 47.3 × 3.0 mm layup.
• Generated voltages of 59.96 mV (Δ10 °C), 130 mV (Δ30 °C), and 278.6 mV (Δ60 °C) with a power density of 86.6 μW/cm² at Δ60 °C.
• Demonstrated robust performance, with no electrical or mechanical failure at strains exceeding 50%.

Conclusions:

• The LMEE-based stretchable TEGs offer a promising solution for self-powered wearable electronics and soft robotics.
• The multifunctional encapsulating LMEE material facilitates simplified integration and enhanced mechanical durability for energy harvesting applications.