Squeeze it and it switches on: tiny cracks let liquid metal wire up stretchy electronics

Soft, stretchable electronics — the kind that could one day sit in wearable health sensors and bendy robots — often mix tiny droplets of a metal that stays liquid at room temperature into rubber. The puzzle was how those droplets ever connect, since the rubber between them normally blocks electricity. A Virginia Tech team led by mechanical engineer Michael Bartlett has now watched it happen: squeeze the material and tiny cracks open between neighbouring droplets, the liquid metal flows in and links them up, and the connections stay in place after the pressure is released. The study, published in Matter, also produced a model that predicts how much force a given design needs to switch on, working from droplets about a millimetre wide down to a few dozen micrometres — a micrometre is a millionth of a metre. What engineers used to find by trial and error can now be designed on purpose.

SDG 9 · Industry, innovation and infrastructure — Mechanism: tech innovation