Forgot your password?
typodupeerror
Science

Mechanically-Created Frictionless Surface 27

Posted by michael
from the as-mu-goes-to-zero dept.
EoRaptor writes "How to enhance the properties of already low friction surfaces down to zero friction. Even water won't stick. I found this link over on Ars Technica. First, I'll build a black ship with black controls that light up black..."
This discussion has been archived. No new comments can be posted.

Mechanically-Created Frictionless Surface

Comments Filter:
  • I (largely) agree with you; I merely responded to the prevous posters suggestion that the lack of friction would prevent a wing from generating lift at all.

    As for the turbulent boundary, I seem to remember that this effect is independent of the friction against the surface, and that the best way to combat this would be managing the microstructure of the surface; making it bumby (in a controlled way), rather than getting it as smooth as possible. Now, IANAE, so please take this with a sack or two of salt.
  • It's not really due to friction; it's rather that the air on the upper side has longer to travel over the wing than the lower side. OTOH, this material won't help with vortex formation, which is (if I remember correctly) the largest part of the drag. OTTH, you need drag - not for generating lift, but for the craft to be stable.

    /Janne
  • I think it's time to take a college-level Intro to Physics course.
  • its not really the material thats innovative, its the process. the material thats 'frictionless' is just a normal non stick surfac (teflon) the difference is that the molecules are packed tighter because the substrate is stretched before the non stick coating is added (the innovation). to remove it from a surface you would remove the subrate from whatever it's attached to. to break it down you would do whatever they do to teflon currently.
  • like the article says it's not a new material, its just a new process for packing molecules tighter. the problem i see for using it in implants is that the substrate could potentially be removed from the surface it's coating, and get stuck somewhere. i don't believe this is really frictionless in the classical sense, just very very smooth. this is definately something worth researching though.
  • Speaking of such things, I just saw a Nova special on PBS the other night about artificial hearts and heart-assist devices. The latest appears to be variations on a thumb sized (well, maybe a fat person's thumb) cylinder that either fits into a heart valve or is attached through a tube near the pointy part of the left ventricle. Inside the cylinder is a 10k-rpm propeller (impeller?) shaped so that the red blood cells don't have a chance to get damaged and start a clotting reaction.
  • I don't think it's indestructable. Its surface is just packed together very tightly so it doesn't react with anything. Seems to me you could still pulverize it so that the uniformity is compromised, then decompose it further chemically.
  • That I'll never have to do dishes again?
    We could have slides that would accelerate toddlers to near mach speeds?
    If they could make this transparent, that I wouldn't have to scrape my windshield?
    If I had furniture made out of this stuff, that I wouldn't have to ever dust again?
  • It won't help with vortex formation. But it has the potential to nearly eliminate the turbulent boundary layer at the wing's surface. The boundary layer isn't the main part of drag, but rather the main obstacle to efficient lift. So a super-smooth coating will allow more lift on a smaller wing. Reducing the surface area should help drag quite a bit.

    As for stability, drag is only required when the craft is not pointing straight ahead. The idea is that as the craft drifts from a proper orientation, the back end begins to experience more drag than the front, pulling the craft back to where it belongs. The drag at the back is produced not by friction, but by a surface (rudder, elevators) which is not oriented parallel to the airflow. So covering the whole thing with super-teflon will not produce any big problems.

  • I'm getting a new one every time I load the page:
    HASH(0x1511df4)
    HASH(0x11f5624)
    HASH(0x1311844)
    ...
  • by MarkusH (198450)

    Now I can get that set of frictionless bedsheets I always wanted!

  • Granted, it would require an initial investment of KE but, if properly designed, then there need not be any extra sources of friction. True, placing the assembly in something like a vacuum chamber to eliminate air friction might be impractical, but I still think it might be possible.
  • IANAAE (I am not an aeronautical engineer) but...

    Lift is produced by differential in pressure between the upper and lower surfaces of the wing - it's shaped so that air meets more resistance on the underside of the wing than on the top of the wing. This means the air flows faster over the top, creating lower pressure there. Higher pressure underneath than above means the wing rises and takes whatever's attached up with it. That's Bernoulli's Principle (I think), and we all probably remember it from high-school science classes.

    BUT - that relies on resistance (friction). If you have a frictionless wing surface, then logically won't you lose the pressure differential that generates lift? And by consequence, won't you be stuck with an ice-proof plane that CAN'T FLY?

    Like I said, I'm not an engineer, but this seems to be a problem...



  • If I had furniture made out of this stuff, that I wouldn't have to ever dust again?

    Yeah, but you'd have to really watch your posture. Slouching could lead to the accelerating toddler effect...

    OK,
    - B
    --

  • I would be nice for a slide and non-electric air hockey.
  • The penultimate use for this stuff is coating the toilet bowl. The Tidy Bowl Man will be unemployed. Hooray!!

    To the Moon!
    http://www.beefjerky.com
  • Now we don't need better bananas to slip on the floor.
  • Not super well thought out, but... Having this stuff coated on the outside of a condom would effectively "lubricate" whatever you wanted to stick your d**k in. Once you have a condom on, and there is no direct skin-to-skin contact, you are not relying on "lack of lube" type of friction, but the sensations of changing pressure, which should not be affected. I think that this would improve the condom. Also, placing some of this on the INSIDE of the condom, (and not completely coating the outside) would allow the man to get a transfer of sensation, since the condom could slip a little more. Got to be carefull you do this in sections/patterns so that the whole thing doesn't slip right off, and you might need to preserve a little friction so that you can feel it! I'll buy them!
  • by Anonymous Coward
    uhh... no. If the polymer is truly 100% frictionless then it might be possible to violate the second law of thermodynamics(I would still doubt it though). But there is still no way to get infinite power (thus violating the first law)! Having no friciton doesn't mean that the generator won't take energy to move... it just means that it doesn't lose any to waste heat generated by friciton. Conservation of energy still applies, and while it might be possible to get a Carnot cycle (highest efficiency possible) going, I would still doubt it because of waste heat generated by other means. so in summary: There is no way this polymer could be used to generate infinite energy, but it could be used to improve efficiency of heat engines if it could stand the temperatures.
  • But can a gecko [slashdot.org] walk on it?
    -russ
  • Could the basic process they use for this
    (stretching a substrate, adding a coating
    and then allowing the substrate to contract) be
    used to create cheaper / smaller / faster chips?

    "The only reason for time is so that everything doesn't happen at once." - Buckaroo Banzai
  • I'm surprised that no one has offered the most obvious application of this product (if truly frictionless): perpetual motion. As I understand it, not having taken any thermodynamics courses, the only thing that stands in the way of perpetual motion is the loss of energy through frictional heat. Remove that energy loss, and something could go forever. Given that a moving magnetic field generates an electric field, then this substance could theoretically be applied to large magnet assemblies such as those in power plants, causing them to move indefinately, thus generating vast amounts of cheap power. I wonder if this will pan out?
  • Wow, something for bus stops and building siding that Grafiti Vandals couldn't spray paint. I wonder if it could be used to stop someone from scratching the paint job on my car.
  • Has anyone thought of how to get rid of this wonderfully inert material once it has out-lived its usefulness?? If it can't be scratched, etc, how can we pull it off something? If it turns out acids don't phase it, how do we break it down to dispose of it? Just a thought...
  • <grumble>the story submitter got to the pun before I could...<grumble>

    "Titanic was 3hr and 17min long. They could have lost 3hr and 17min from that."
  • by anvilmark (259376) on Tuesday January 09, 2001 @02:37PM (#519351)
    Wow. I can't believe that the moderators haven't put this one on the main page. This could change mechanical engineering like the transistor changed computing.
    Yes, I know it probably isn't magic, but think of all the things where friction is a limiting factor. Even if this type of coating only HALVES the friction force, the impact would be incredible. If it really is as non-reactive as they are saying, a whole new class of containers and transmission conduits would spring into being.
    What's more, this sounds like a relatively straight-forward manufacturing process and could probably be incorporated into almost anything where one part rubs on another or needs to be protected from the elements.
    I want more specs! How hard is this stuff, could it function as a cheap substitute for industrial diamond coatings? Is this stuff a conductor or insulator (either? semi?) At those densities, how does it bleed heat?
    Bond a coating of this stuff to ship hulls and watch those barnacles try and get a grip! That alone would revolutionize the costs of sea transport. Not to mention the reduction in friction effects for the hull itself. Anything that has to resist the effects of sea water would be transformed.
    Near frictionless bearings without magnetics or lubrication, now THAT would be cool...
  • by Bonker (243350) on Tuesday January 09, 2001 @01:09PM (#519352)
    One of the biggest problems facing medical researchers who have been trying to come up with a decent way to run a good artificial heart has been the lack of substances with which to build the thing.

    Barney Clark, the first artificial heart recipient, died of a stroke due to clotting in the device that eventually traveled to his brain. The new 'heart assist' pumps that are in use now that aid patients until their heart heals from an injury or disease, or until they can find a donor heart are made with certain ceramic materials that are so irregular that blood clots on them more rapidly than on smooth polymers and metals that were used in earlier devices.

    The theory behind these is that because the surface is so rough, the blood clots that do form are much less likely to break off and work their way into a critical artery blockage. It seems to work, but these devices are *Very* high maintenance and require tubes and/or wires to extend from the chest cavity to power them.

    This new material could have a profound effect on artificial organ research because, like the smooth muscle of the heart, blood won't clot on this stuff. If the research proves out, artificial heart devices can be made smaller, more powerful and less intrusive.

    I just hope these guys realize this and will provide samples to research hospitals...

You've been Berkeley'ed!

Working...