Researchers add new twist to sensors and wearable tech

"We have created soft and stretchable fibres that can detect touch, as well as strain and twisting,” said Michael Dickey, a professor of chemical and biomolecular engineering at NC State and corresponding author of a paper describing the work. “These microscopic fibres may be useful for integrating electronics in new places, including wearable devices."

According to NC State, the new fibres are made of tube-like polymer strands that are a few hundred microns in diameter and contain eutectic gallium and indium (EGaIn), which is a liquid metal alloy.

Each fibre consists of three strands with one completely filled with EGaIn, one two-thirds filled with EGaIn, and remainder one-third filled with EGaIn. The tubes are then twisted together into a tight spiral.

The touch-responsive fibre is capacitive and works in the same way as touch screens on smartphones. Capacitance describes the phenomenon of an electric charge that is stored between two conductors and separated by an insulator.