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Laser-Textured Metal Surfaces Kill Bacteria Faster:
Copper surfaces kill microbes that come into contact with them in a matter of hours. A new technique makes the familiar metal even deadlier—by zapping it with lasers.
Bacteria “are becoming more aggressive and resistant to therapeutics; it's the same thing for viruses,” says Rahim Rahimi, a materials engineer at Purdue University and senior author of a paper on the new process, published in April in Advanced Materials Interfaces.
[...] Copper's germ-destroying power, [microbiologist Michael Schmidt] explains, comes from its ability to conduct electricity. When a microbe touches a metal surface, the substance carries electrons away from the microbe's cellular membrane. This reaction sets off a chemical process that ultimately forces open the organism's pores and destroys it.
[...] To enhance the process, Rahimi's team hit a copper sample with laser light for a few milliseconds, thereby creating nanoscale pores in the flat metal and increasing its surface area.
[...] The researchers tested this newly rugged terrain by placing several bacterial strains, including Escherichia coli and a drug-resistant Staphylococcusaureus strain, on both flat and laser-treated pieces of copper. As soon as the cells hit the textured metal, their membranes began to suffer damage; that surface completely eradicated the bacteria, in some cases much more quickly than the untreated one. The surface killed some microbes immediately on contact and took from 40 minutes to two hours to wipe out a full colony, depending on the species and concentration.
Journal Reference:
Vidhya Selvamani, Amin Zareei, Ahmed Elkashif, et al. Hierarchical Micro/Mesoporous Copper Structure with Enhanced Antimicrobial Property via Laser Surface Texturing [$], Advanced Materials Interfaces (DOI: 10.1002/admi.201901890)
(Score: 1, Interesting) by Anonymous Coward on Sunday July 19 2020, @09:18PM (1 child)
I shall build a suit of copper armor, and thus be invincible to all known disease!
But wait! Does the copper still work against the tiny foes when it hath gained its green patina?
(Score: 0) by Anonymous Coward on Sunday July 19 2020, @11:41PM
Get out the Brasso polish.
(Score: 0) by Anonymous Coward on Sunday July 19 2020, @10:05PM (1 child)
Try sandblasting the copper surface. Or is that too (in)expensive?
(Score: 3, Informative) by c0lo on Monday July 20 2020, @12:06AM
Too large texture features.
But you can use sputtering, no need for more than a glow discharge in gases [wikipedia.org]. You can even DIY [youtube.com]
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 5, Interesting) by c0lo on Sunday July 19 2020, @11:43PM (1 child)
Nano-spikes are killing E coli/S.aureus at least since 2010. And the electrochemical potential of a metal is not necessary for the kill.
2010 - on silver and on copper [mdpi.com]
2015 - on plastic!! [nih.gov] - electrochemical potential plays no role in this one, the nanotexture does. Even nice, the plastic is nanotextured in molds.
2017 - stainless steel [gatech.edu]
2019 - using Ti-Al alloy [manchester.ac.uk]
2019 - on Ti [frontiersin.org]
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by c0lo on Monday July 20 2020, @10:09AM
There may be something original in this one, tho'.
All the others (that I browsed) ended with a hydrophobic surface - either by texturing alone or by special treatment happening during texturing. However, from TFA(bstract) of this one however:
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by Runaway1956 on Monday July 20 2020, @12:26AM
https://www.sciencenewsforstudents.org/article/repelling-germs-sharkskin [sciencenewsforstudents.org]
New study kinda sorta confirms old study here? Bacteria and other bad creatures don't like surfaces that they can't "hold on to".
(Score: 0) by Anonymous Coward on Monday July 20 2020, @01:06AM
Nanotexturing creates bacteria-killing spikes on stainless steel surfaces (2017) [phys.org]
(Score: 2) by stretch611 on Monday July 20 2020, @09:03AM (1 child)
Wouldn't the same process affect human cells as well? Wouldn't touching a metal surface essentially cause electrons to be ripped away from my skin cells just as easily as a microbe?
Or, is this a case where it goes unnoticed because a human sheds/replaces skin cells on a regular basis and new skin cells are created to replace the old damaged ones? (i.e. it does happen but at a rate slower then the skin's normal regeneration.)
Now with 5 covid vaccine shots/boosters altering my DNA :P
(Score: 0) by Anonymous Coward on Monday July 20 2020, @01:01PM
Your outer layer of skin is dead already.
Look up "epidermis." It's a protective shell for your body. Otheewise, you couldn't even grab a pinch of salt without your fingers throbbing in pain.
(Score: 1) by khallow on Monday July 20 2020, @11:58AM
For a related example, we have bacteria that can live in very hot water (80 C, for example) and bacteria that can live in extremely salty water, but not bacteria that can do both equally well.