Liquid metal slingshot

This Rapid Communication presents the self-propelled and controllable motion of liquid metal droplets, which is driven by surface tension and does not depend on any external force field. Its motion speed and direction can be controlled just as a projectile fired by a slingshot: The liquid metal droplet is the projectile, and a substrate surface serves as the bowstring. This motion provides a potential mechanism for the application of liquid metals in soft robotics, drug delivery, chip cooling, and other fields.Received 11 March 2020Accepted 16 October 2020DOI:https://doi.org/10.1103/PhysRevFluids.5.111601©2020 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasDrop & bubble phenomenaSurface tension effectsPhysical SystemsLiquid metalsLiquid-liquid interfacesFluid DynamicsCondensed Matter, Materials & Applied PhysicsBiological Physics