Mass Production of Nanomaterials
Tanya Trofimencoff posted on March 23, 2016 |
Increasing production of the smallest but most useful materials of the century.

Nanoparticles play an important role in technological advancements in medicine, engineering and other applications. The question is, how can nanoparticles be manufactured more efficiently? Although there is a myriad of uses for these tiny particles, production is expensive.

What if there was a way to bring this cost down? With a lower time and cost to produce these particles, the market for nanomaterials would have the potential for significant growth.

For example, gold nanoparticles play a role in medicine. Foreign object penetration usually damages or even kills cells, but these particles can penetrate cell membranes without causing damage. This makes them ideal transporters of medicine to normal cells or radiation to cancerous cells.

The cost of gold nanoparticles production is USD$80,000 per gram (where a gram of raw gold is USD$50), but it’s the bottleneck of batch processing that creates such high costs of production.

Researchers at USC have found an automated manufacturing process that holds the potential to replace the tedious batch process presently used.

The team’s research. (a) A CAD rendering of the droplet generator with a single outlet for tubing to control droplet size; (b) a CAD rendering of the droplet generator using stereolithography (SLA) instead of tubing; (c) Micrographs depicting the droplet breakup process; (d) Micrographs of the droplet breakup process in SLA generators. (Image courtesy of Malmstadt et. al.)
The team’s research. (a) A CAD rendering of the droplet generator with a single outlet for tubing to control droplet size; (b) a CAD rendering of the droplet generator using stereolithography (SLA) instead of tubing; (c) Micrographs depicting the droplet breakup process; (d) Micrographs of the droplet breakup process in SLA generators. (Image courtesy of Malmstadt et. al.)

“It’s not the gold that’s making it expensive,” said Noah Malmstadt, of USC Viterbi School of Engineering. “We can make them, but it’s not like we can cheaply make a 50-gallon drum full of them.”


The Fluid Fix

Manufacturing nanoparticles currently involves mixing a batch of chemicals by hand in lab flasks and beakers. The new technique used by Brutchey and Malmstadt relies on micro-fluidics instead. Through narrow channels, tiny droplets of fluid are manipulated.

Here’s a look at how it works:

“In order to go large-scale, we have to go small,” said Richard Brutchey of the USC Dornsife College of Letters, Arts and Sciences.

The process uses 3D printed tubes, just 250 micrometers in diameter. That’s five times smaller than the width of a speck of dust. The team tested four parallel tubes by running non-mixing fluids such as oil and water through each tube. As the fluids tried to squeeze through the tubes, they formed droplets at the tubes’ openings.

Similarly to the process in a chemical reactor, two materials are mixed to produce nanoparticles. Each tube created millions of identical droplets.

Early attempts were unsuccessful because jams in the tubes would create pressure changes that affected the entire system. Researchers changed the tube geometry at the junctions between tubes to ensure uniform nanoparticle formation. Maintaining these conditions made the system immune to pressure changes.


Global Impact

Facilitating nanoparticle production could help increase applications such as health care, consumer goods, construction and engineering. The industry predictions show that the nanomaterials market has the potential to grow from USD$3.4 billion in 2015 to USD$11.8 billion by 2020.

Reducing lost time in production can bring about significant research developments in the near future. Applications include catalyst use in chemical engineering processes, drug-delivery formulations, high-definition televisions, scratch-proof glasses, self-cleaning windows, solar steam devices and endless others.

For more information, check out the team’s research here.

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