Today, New Scientist reports on how a technology intended to solve a problem can be successfully used ten years later to solve a totally different one. In "Hi-fi failure helps to brighten beer," the magazine says that in the early 1990s, Philips developed a technology to enhance the sound quality of audio tapes. As tapes were dethroned by CDs, Philips didn't have any use for this technology. But now, a small Dutch company, fluXXion, is using it to develop micro filters. And these filters are currently used by Dutch brewer Bavaria to remove yeast residues from its beers.
Here are some short details about the technology.
To make their filters, Fluxxion places a 15-centimetre-wide silicon wafer disc - the sort microchips are made on - in a vacuum and uses a plasma beam to blast 3 billion 0.45-micrometre holes through the wafer. The wafer is then rinsed.
The two images above, extracted from fluXXion's website, show different views from these micro sieves (Credit: fluXXion).
What can we do with these filters?
The ultra-fine filter is a boon to brewers who need to remove cloudy yeast residues. Conventional beer filters are made of either densely packed fibres or a dusty material called kieselguhr, which consists of fossilised hard-walled algae called diatoms.
New Scientist explains that this conventional process is long and delicate, so brewers are searching for a different one.
To test the silicon filter, the Bavaria Brewery of Brabant in the Netherlands, gave Fluxxion cloudy barrels of freshly brewed beer to try filtering in the lab. The beer cleared so well that Bavaria installed its own pilot plant eight weeks ago.
According to New Scientist, fluXXion envisions other usages for these filters.
Fluxxion is testing it on milk to see if it can filter out bacteria and thus avoid pasteurisation, which can impair the taste. The firm is also experimenting with filters with 0.2-micrometre holes, to see if they can remove viruses from blood plasma.
For more information about the technology, you can check this page describing fluXXion's filtration methods.
Sources: Barry Fox, New Scientist, July 12, 2004; fluXXion website
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