4 ms·
Silicon spikes take out 96% of virus particles
- r-johnv 3y agoSo many questions: Do the spikes get broken or rubbed off if touched by or hands (for example of used on a doorknob as they mentioned) So they kill viruses if they land on it in a droplet
- thsksbd 3y agoIf this had been made with copper or steel, id be more impressed. Right note I'm just dreading that we're going to flood our environment with another forever material.
- compressedgas 3y agoPersonally less a forever material and more a new asbestos.
- Cthulhu_ 3y agoDoes this mean everyone's favorite word, pneumonoultramicroscopicsilicovulcanoconiosis, will become mainstream?
- ben_w 3y agoOnly hippopotomonstrosesquippedaliophilies, nerds, and people who have been dared to attempt to pronounce it aloud in the presence of others, will care to use it.
- deleted 3y ago[deleted]
- ralusek 3y agoGill got that from a commercial
- thsksbd 3y agoIts a good descriptor of what it is. And this will last a lot linger than fluorinates
- thsksbd 3y agoAsbestos is a forever chemical. One made naturally. Asbestos is an amazing. Im really annoyed I cant buy it - as a professional - to play with. But it's amazing because it is forever chemical.
- Intralexical 3y agoOn a serious note, since asbestos is fibrous, with asbestos it's the entire volume of the material that can be problematic, right? Adding a sub-micrometer thick layer of spikes probably isn't as bad.
- thsksbd 3y agoIm not worried about a spiky slab. Im worried when the spikes are sheared off and join nature. You can argue that the amounts would be minuscule since the spikes are only on a surface, but no one has.
- Latty 3y agoSilicon is hardly some wild exotic material, we are talking about 30% of the Earth's crust here. I can understand worrying if this could impact other things in this form, but I'm not sure why making it out of copper or steel instead would matter.
- flybrand 3y agoAgreed - we’ve got a lot of ‘forever materials’ out on the beach and converted into glass windows.
- thsksbd 3y agoHardly nano scale shaped fibers, are they? And btw, silicosis from weathering sand is a thing.
- thsksbd 3y agoBut the shape isn't that common. Except in things that are highly regulated materials, like asbestos, which is long fibers of SiO2. SiO2, which is exactly what these Si fibers will become as soon as it is in contact with air. A material that can puncture cell membranes and is almost certainly a catalyst.
- Latty 3y agoI don't really understand the focus on the material rather than the shape then, why would copper in this shape not be a problem?
- thsksbd 3y agoBecause SiO2 is one of the most stable minerals known, whereas copper and iron (and their oxides) are not; they readily chemically and biologically available and will be dealt with by the body. Keeping iron from dissolving is hard Dissolving SiO2 is nearly impossible (one of the many great advantages SiO2 brings in Si in lithograpjy). EDIT: You can do these experiment at home! Buy very fine iron wool and some fiber glass. The giber glass is a stand in for asbestos. Warning! these experiments involve fire or the evolution of corrosive fluids. Blow torch the iron and glass wool. How do they fare? WARNING! This fire is very hard to put out. Mix bleach with iron wool and glass wool. Mix vinegar. Note, for best results use organic apple vinegar with the mother, or a too shelf Japanese rice vinegar Mist the iron wool and the fiber glass with water. RESULT: In all these experiments glass was unfazed. Iron didn't make it in any. Sometimes violently.
- ben_w 3y agoWhy do you think the specific element matters? Why is this being made from silicon — one of the main elemental components of most rock and sand — something you denounce as a "forever material" when you're fine with copper and steel?
- lazide 3y agoI’m guessing because silicon is longer lasting? Essentially forever except for mechanical weathering. Diatomaceous earth, for example. Asbestos for another. Steel and even copper degrade much quicker.
- ben_w 3y agoDiatomaceous earth and asbestos are categorised as silicates, which is the oxide of silicon rather than the pure metal. Metallic silicon is different from silicon oxide in the way that water is different from hydrogen gas or that charcoal is different from carbon dioxide… or that steel is different from rust and copper different from verdigris. Also notable: some of the common forms of asbestos have almost as many iron atoms as silicon in the chemical formula, and all the ones I looked at have far more oxygen.
- lazide 3y agoGood points! I guess the big question would be if the oxidized form (the silicon oxide structure) would be safer (similar to rust) or dangerous. At least silicosis shouldn’t be a real risk at the quantity used I would hope?
- Cheer2171 3y agoSilicon is chosen precisely because it is much easier to turn into small fibers, literally just like asbestos. Silicon is the second most abundant material in asbestos, after oxygen.
- yread 3y agohttps://en.m.wikipedia.org/wiki/Silicosis https://en.m.wikipedia.org/wiki/Silicosis I hope it doesn't catch up
- flybrand 3y ago> the spike design to be extremely effective at damaging the virus’ external structure and piercing its membranes It’s always great to see more methods of microorganism control - but the challenge here is that the same mechanism likely kills many other microorganisms. Testing it to see that it is ‘safe’ in other settings is expensive and time consuming.
- fartcry2200 3y ago[dead]
- sleepingreset 3y agohttps://xkcd.com/1217/ https://xkcd.com/1217/
- denton-scratch 3y agoUm, title: the spikes take out 96% of virus particles that come into contact with them. So the next problem is: how do you make virus particles come into contact with this surface? If you wait for them to fall onto it, you could be waiting a very long time. Also, the virus has to be sitting on the spikes for several hours. This is very interesting work, but there's a lot to be done before there are practical applications, no?
- Solvency 3y agooh cool, a brand new way to cause lung cancer!
- hristov 3y agoThey did not mention whether it damages human skin. If it rips viruses apart how do skin cells fare? The way that researcher is gingerly holding the material with forceps without touching it does not inspire confidence. Furthermore i know the high level development of the integrated circuit industry inspires other industries to try to make things from silicon wafers, one should keep in mind that silicon wafers are still quite expensive and probably too expensive for human scale objects. The reason they work for chips is that the silicon part of chips (without the plastic and copper packaging) tends to be very small. These researchers should take a cue from the oled display industry and try to make their spikes in annealed amorphous silicon. That may be affordable enough to make stuff from.
- Retric 3y agoThe top layer of skin is several layers of dead cells. This might act like sandpaper, but the bumps are less than the width of a single cell they aren't going to reach living skin cells by just holding it. https://en.wikipedia.org/wiki/Epidermis https://en.wikipedia.org/wiki/Epidermis It's quite clever if you think about it. A virus can easily attack living cells but they aren't don't anything to a layer of dead cells. Similarly it doesn't need to be warm and moist to keep cells alive etc.
- deleted 3y ago[deleted]
- weare138 3y agoThe spikes would be so small they wouldn't affect your skin cells. Viruses are magnitudes smaller than cells and your skins cells have thick, durable cell walls to protect them. It's no different than other materials like copper and silver that also exhibit natural antiviral/antibiotic properties. A piece of polished copper would feel smooth to the touch but if you looked at it under a high power microscope the surface would appear rough and jagged like the silicon spikes.
- Retric 3y agoI wouldn’t assume the surface is going to maintain these precise nano structures after rubbing your finger across it. So yes it might feel smooth, but IMO it could also feel gritty from structures larger than a single spike breaking off. It really depending on how exactly it’s made/ what it’s applied to not just the initial shape.
- jmatthews 3y agoCopper and copper alloys are great antiviral and antimicrobial. Why not work out the minimum deposition required to create that mechanic?
- chasil 3y agoThis is due to the oligodynamic effect, and silver is equally potent. https://en.m.wikipedia.org/wiki/Oligodynamic_effect https://en.m.wikipedia.org/wiki/Oligodynamic_effect
- perihelions 3y agoHow does this material degrade? Do the spikes break off? If so, does the nanometer-size spiky silicon dust persist in the environment, or are they destroyed or neutralized somehow? late edit: I think it might (?) be functionally similar to fine silica dust, because (says the linked paper) the spiky surface is passivated with SiO2. ("...confirmed the presence of a thin SiO2 surface passivation layer on both planar and nanostructured Si surfaces...")
- blueflow 3y agoBut if you touch it, it will get human grease on it quickly. How will you clean it?
- burner420042 3y agoEveryone is stuck on their word choice and the associated mental imagery. How about: Two-dimensional silicon latices found affective at neutralizing virus particles
- binary132 3y agoAw sweet, nanotechnology horrors beyond my imagination
- mateo1 3y agoIt's really cool to be able to make a surface like this and prove it does kill viruses (even cooler since it exists in nature), but obviously it has no practical use. It would only work in a cleanroom for a little while until it clogs, and I don't see the benefit over a regularly sanitized surface. Also viri usually don't go floating about as singular particles, the associated snot would deactivate the surface's properties.
- Intralexical 3y agoSeems… Unnecessarily complicated: > Copper and its alloys (brasses, bronzes, cupronickel, copper-nickel-zinc, and others) are natural antimicrobial materials. > After incubation for one hour on copper, active influenza A virus particles were reduced by 75%. After six hours, the particles were reduced on copper by 99.999%. Influenza A virus was found to survive in large numbers on stainless steel. > In a recent study, 75% of adenovirus particles were inactivated on copper (C11000) within one hour. Within six hours, 99.999% of the adenovirus particles were inactivated. Within six hours, 50% of the infectious adenovirus particles survived on stainless steel. https://en.wikipedia.org/wiki/Antimicrobial_properties_of_copper https://en.wikipedia.org/wiki/Antimicrobial_properties_of_co... Though I guess it's probably faster if it physically punctures the virus, and two hours is still a significant amount of time for infection to occur with a regularly shared surface. Salt has a similarly fast effect on viruses: > Whitlock found that salt killed off the bug 20 to 30 times faster than the copper did, reducing MRSA levels by 85 percent after 20 seconds, and by 94 percent after a minute. https://www.theatlantic.com/health/archive/2017/03/salt-vs-superbugs/518427/ https://www.theatlantic.com/health/archive/2017/03/salt-vs-s... Other than osmosis dessicating the virus, when the moisture dissolves the salt and then dries in a minute or two, the salt crystals physically puncture the virus's envelope, IIRC. https://www.ualberta.ca/folio/2020/10/u-of-a-researcher-working-on-salt-coated-masks-that-can-kill-coronavirus.html https://www.ualberta.ca/folio/2020/10/u-of-a-researcher-work... Though having a water-soluble and electrolytic desiccant covering everything obviously raises its own problems, and having tried this at the very start of the pandemic, I can say you really don't want to be breathing in salt dust all day.
- Intralexical 3y ago> The result is a surface full of needles that are 2 nanometers thick – 30,000 times thinner than a human hair – and 290 nanometers high. Ooh. That's right around the correct range for structural colouration. You could draw designs with this, or utilitarian colour-coding. Red (700nm) means danger— The spikes will get bacteria, but are too big for viruses.