Microtechnology speeds nanoparticle production

Engineers at Oregon State University (OSU) say they have discovered a new method to increase the rate at which nanoparticles are produced.

The advance could potentially play an important role in making nanotechnology products more commercially practical.

The approach uses an arrayed microchannel reactor and a ‘laminated architecture’ in which many sheets, each with thousands of microchannels in them, are stacked in parallel to provide a high volume of production and good control of the processes involved.

Applications could be possible in improved sensors, medical imaging, electronics and solar energy or biomedical uses when the same strategy is applied to materials such as copper, zinc or tin.

A patent has been applied for, university officials said. The work, published in the journal Nanotechnology, was done in the research group of Brian Paul, a professor in the OSU School of Mechanical, Industrial and Manufacturing Engineering.

‘A number of new and important types of nanoparticles have been developed with microtechnology approaches, which often use very small microfluidic devices,’ said Chih-hung Chang, a professor in the OSU School of Chemical, Biological and Environmental Engineering and principal investigator on the study.

‘It had been thought that commercial production might be as simple as just grouping hundreds of these small devices together,’ Chang added. ‘But with all the supporting equipment you need, things such as pumps and temperature controls, it really wasn’t that easy. Scaling things up to commercial volumes can be quite challenging.’

The new approach created by a research team of five engineers at OSU used a microreactor with the new architecture that produced ‘undecagold nanoclusters’ hundreds of times faster than conventional ‘batch synthesis’ processes that might have been used.

‘In part, because it’s faster and more efficient, this process is also more environmentally sensitive, using fewer solvents and less energy,’ Chang said. ‘This could be very significant in helping to commercialise nanotech products, where you need high volumes, high quality and low costs.’

This research, added Chang, created nanoparticles based on gold, but the same concept should be applicable to other materials as well.

By lowering the cost of production, even the gold nanoclusters may find applications because the cost of the gold needed to make them is actually just a fraction of the overall cost of the finished product, explained Chang.