Liquid Metal-Enabled, Micro-Scale Pump with No Mechanical Parts

Researchers at Australia's RMIT University have developed a liquid metal-enabled pump - a breakthrough for micro-fluidics and lab-on-a-chip technology, and for applications ranging from biofuels to biomedicine. The device has no mechanical parts and can be easily produced. The design uses droplets of the liquid metal alloy Galinstan as the core of the pumping system to induce flows of liquid in looped channels. Galinstan is made up of of gallium, indium, and tin. 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 - a process called continuous electrowetting. The pump is highly controllable, with the flow rate adjusted by altering the frequency, magnitude, and waveform of the applied signal. The flow direction can be easily reversed by reversing the polarity of the applied voltage.