Australian researchers have developed a new micro-scale device functioning as a liquid-metal-enabled pump.
The device, described in this week’s Proceedings of the National Academy of Sciences, was said to be opening new opportunities in many applications including biomedicine and biofuels.
According to Khashayar Khoshmanesh, a research fellow at the Centre for Advanced Electronics and Sensors at the Royal Melbourne Institute of Technology and one of the authors of the invention, the microscopic liquid fuel pump provides far more efficient ways to drive liquid around a fluidic chip in micro-fabricated systems than currently existing technologies.
“Lab-on-a-chip systems hold great promise for applications such as biosensing and blood analysis but they currently rely on cumbersome, large-scale external pumps, which significantly limit design possibilities,” said Khoshmanesh.
“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."
Khoshmanesh believes the device could have a similar effect on chemicals processing and bio-particles manipulation as integrated micro-electronics had on information processing, enabling the development of computers and smartphones.
“This innovation shows that micro- and nano-scale pumping can be accomplished with a simple system – a crucial advance for the field of micro-fluidics,” he said.
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.