The team has used the sound waves to drive crystallisation for the sustainable production of metal-organic frameworks, or MOFs.
Predicted to be the defining material of the 21st century, MOFs are ideal for sensing and trapping substances at minute concentrations, to purify water or air, and can also hold large amounts of energy, for making better batteries and energy storage devices.
While the conventional process for making a MOF can take hours or days and requires the use of harsh solvents or intensive energy processes, the RMIT team has developed a clean, sound wave-driven technique that can produce a customised MOF in minutes and can be easily scaled up for efficient mass production.
Sound waves can also be used for nano-manufacturing 2D materials, which are used in myriad applications from flexible electric circuits to solar cells.
Scaling up and pushing boundaries
The next steps for the RMIT team are focused on scaling up the technology.
At a low cost of just $US0.70 per device, the sound wave-generating microchips can be produced using the standard processes for mass fabrication of silicon chips for computers.
“This opens the possibility of producing industrial quantities of materials with these sound waves through massive parallelisation – using thousands of our chips simultaneously,” Yeo said.
The team at the Micro/Nanophysics Research Laboratory, in RMIT’s School of Engineering, is one of just a few research groups in the world bringing together high-frequency sound waves, microfluidics and materials.
Yeo says the research challenges long-held physics theories, opening up a new field of “high frequency excitation” in parallel to sonochemistry.
“The classical theories established since the mid-1800s don’t always explain the strange and sometimes contradictory behaviour we see – we’re pushing the boundaries of our understanding.”