Researchers at RMIT University in Melbourne, Australia, say they have developed the world’s first micro-scale liquid metal enabled pump with no mechanical parts. The new pump design has potential to greatly enhance the capabilities of micro-fluidics and lab-on-a-chip technologies in applications that could range from biomedicine to biofuels.
The lead investigator, Dr Khashayar Khoshmanesh, a Research Fellow in the Centre for Advanced Electronics and Sensors at RMIT, said currently there was no easy way to drive liquid around a fluidic chip in micro-fabricated systems.
“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,” he said in a statement. “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.”
Micro-fluidics has the potential to “revolutionize” the way we process and manipulate chemicals and bio-particles at the micro scale. The RMIT innovation shows that micro-scale and nanoscale pumping can be accomplished with a simple system, a “crucial advance” for the field, according to Khoshmanesh.
The RMIT design uses droplets of a non-toxic alloy called Galinstan, comprising gallium, indium and tin as the core of the pumping system that induces the flow of liquid in looped channels. When electrical voltage is applied to the Galinstan, the liquid surrounding it is propelled through the loop, while the Galinstan remains motionless. The flow rate of the pump can be controlled by altering the frequency, magnitutde and waveform of the applied signal. Flow direction can also be reversed by reversing the polarity of the applied voltage.
The field of micro-fluidics has applications in the fields of pharmaceuticals, in-vitro diagnostics, and drug delivery devices among others. The market for micro-fluidics is expected to grow quickly, in part due to increasing demand for point-of-care devices in mobile health care.
