Electric field assisted motion of a mercury droplet

Field-assisted self-assembly, motion, and manipulation of droplets have gained much attention in the past decades. We exhibit an electric field manipulation of the motion of a liquid metal (mercury) droplet submerged in a conductive liquid medium (a solution of sulfuric acid). A mercury droplet moves toward the cathode and its path selection is always given by the steepest descent of the local electric field potential. Utilizing this unique behavior, we present several examples of droplet motions, including maze solving, electro-levitation, and motion on a diverted path between parallel electrodes by controlling the conductivity of the medium. We also present an experimental demonstration of Fermat's principle in a non-optical system, namely a mercury droplet moving along a refracted path between electrodes in a domain having two different conductivities.

Automated summary

The study demonstrates the motion of liquid metal droplets in a conductive liquid medium under electric field manipulation. The droplet moves towards the cathode following the steepest descent of the local electric field potential. Various examples of droplet motions were shown, such as maze solving, electro-levitation, and controlled motion between parallel electrodes by adjusting the medium conductivity.