RMIT University researchers have developed the world's first liquid metal enabled pump, a revolutionary new microscale device with no mechanical parts. The unique design will enable micro-fluidics and lab-on-a-chip technology to finally realize their potential, with applications ranging from biomedicine to biofuels.
Lead investigator Dr Khashayar Khoshmanesh said currently there was no easy way to drive liquid around a fluidic chip in microfabricated systems. "Our unique pump, enabled by a single droplet of liquid metal, can be easily integrated into a micro-device, has no mechanical parts, and is both energy efficient and easy to produce or replace."
The design uses droplets of Galinstan – a non-toxic liquid metal alloy comprised of gallium, indium and tin – as the core of a pumping system to induce flows of liquid in looped channels. When the alloy is activated by applying a voltage, the charge distribution along the surface is altered. This propels the surrounding liquid without moving the Galinstan droplet through the loop, using a process called continuous electrowetting."
The pump is highly controllable, with the flow rate adjusted simply by altering the frequency, magnitude and waveform of the applied signal. The flow direction can also be readily reversed by reversing the polarity of the applied voltage.