Noncoalescent liquid metal droplets sustained on a magnetic field-circulated liquid metal bath surface

When exerting a rotating magnetic field on a liquid metal bath, the bath is driven to flow toward the magnetic field direction through the induced Lorentz force. Past a critical speed, a stable ring-shaped bath configuration is formed, and a droplet of the same liquid metal can persistently move without coalescence on the bath surface with a lubricating NaOH solution film between the two liquid metal bodies. The lubricating film allows the levitating droplet to rotate in the direction of the magnetic field. The magnetic field induced noncoalescence effect provides a noninvasive method to manipulate and study liquid metal droplet behavior on a soft substrate.