DESIGN AND PERFORMANCE OF STRETCHABLE THERMOELECTRIC NANOWIRE COMPOSITES

Thermoelectric materials efficiently and directly convert waste heat into electricity, enabling new engineering applications ranging from micro scale solid-state cooling in computers to clean energy harvesting and conversion. For example, thermoelectric alloys have been useful for past NASA missions in deep-space exploration outside the solar system, where traditional solar cells cannot function properly due to the lack of light. NASA uses radioisotope thermoelectric generators on satellites, taking the hot particles from the decay of a radioactive isotope, to heat thermoelectric alloy coatings that generate electricity. The problem with these alloy coating materials, however, stems from their poor mechanical strength. They are generally brittle and break under very small elastic deformation, which makes their integration to curved surfaces or soft fabrics impossible. This study presents optimal conditions to control the growth and harvesting of the nanowires to achieve longer lengths in order to increase conductivity, a substrate that is flexible and stretchable enough, but also strong enough to be considered for wearable electronics, and the mechanical performance of newly-developed flexible polymer composites containing a dense network of thermoelectric alloy nanowires with a diameter less than 200 nm. Further research on such elastically-compliant nanowire-based composite materials could lead to significant technological breakthroughs such as enabling computers to be integrated into clothing, powered by body heat, or cutting down on waste energy from excess heat by wrapping them around hot exhausts and engines to power electrical devices