Slashdot Mirror


Plastic That Changes Shape In Light

JLavezzo writes "Picture a flower that opens when facing the sunlight. In work that mimics that sensitivity to light, MIT Engineer Robert Langer and his German colleagues have created the first plastics that can be deformed and temporarily fixed into shape by light. This material could one day lead to medical devices that build themselves inside a patient's body, or door latches that can be opened with a flashlight. Additional commentary available at The Science Blog"

23 of 123 comments (clear)

  1. Heat and Artificial Muscles? by Greg+Wright · · Score: 5, Informative

    They, the scientists, have been able to do this for some time with
    heat. The link below is to an article that shows a 30 gram weight
    being lifted and lowered by a type of polymer know as nematic
    elastomers.

    http://www.sciam.com/article.cfm?articleID=0007C 55 D-FA8F-1C5F-B882809EC588ED9F

    they also say in the above article(link) that, "..light can also induce
    shape changes anywhere from 10 to 400 percent [in the polymer]."
    However, it takes a hours for it to return to the original shape.

    One of the best applications,in my opinion, for any fast-acting shape
    changing polymer would be as artificial muscles. Not sure how
    practical or easy that might be. You would have to get the temperature
    range, where the shape changing takes place, down pretty low and find
    a way to control it outside of the body's heat influence. I am sure
    there are other problems as well.

    --
    --greg Vulcan quiescent... Q: What machine shutdown with this message?
  2. Light inside the body? by LiquidCoooled · · Score: 5, Funny

    I thought you couldn't light the inside your body.

    I was under the assumption that was the one place the sun don't shine.

    --
    liqbase :: faster than paper
  3. I can see the warning signs now by homer_ca · · Score: 5, Funny

    No Flash Photography Please

  4. doors? by Anonymous Coward · · Score: 2, Insightful

    Why would you want a door that opens to light?

    1. Re:doors? by BobPaul · · Score: 2, Insightful

      The plastic only reacts to certain frequencies, and this is better than an electronic solution since it'll work when the power's out.

      It won't automatically open the door when the sun shines on it...

      Anyway, the door thing really just sounds like a semi-cool idea, not anything really marketable or practical...

  5. Coming to a WalMart Near You! by ackthpt · · Score: 2, Funny
    This material could one day lead to medical devices that build themselves inside a patient's body, or door latches that can be opened with a flashlight.

    Yeah, like Shrinky Dinks this'll be a hit with the mail-order or discount store crowd before you know it.

    People tend to forget what cyanoacrylate's first purpose was.

    --

    A feeling of having made the same mistake before: Deja Foobar
    1. Re:Coming to a WalMart Near You! by mesach · · Score: 4, Informative

      One of the first widespread uses maybe but not first purpose. It was used in medical means over 20 years after its invention.

      Pasted from the straight dope

      "Super glue, Krazy glue, Eastman 910 and similar glues are all a special type of glue called cyanoacrylates. Cyanoacrylates were invented in 1942 by Dr. Harry Coover of Kodak Laboratories during experiments to make a special extra-clear plastic suitable for gun sights. He found they weren't suitable for that purpose, so he set the formula aside. Six years later he pulled it out of the drawer thinking it might be useful as a new plastic for airplane canopies. Wrong again--but he did find that cyanoacrylates would glue together many materials with incredible strength and quick action, including two very expensive prisms when he tried to test the ocular qualities of the substance. Seeing possibilities for a new adhesive, Kodak developed "Eastman #910" (later "Eastman 910") a few years later as the first true "super glue." In a now-famous demonstration conducted in 1959, Dr. Coover displayed the strength of this new product on the early television show "I've Got a Secret," where he used a single drop placed between two steel cylinders to lift the host of the show, Garry Moore, completely off of the ground.

      The use of cyanoacrylate glues in medicine was considered fairly early on. Eastman Kodak and Ethicon began studying whether the glues could be used to hold human tissue together for surgery. In 1964 Eastman submitted an application to use cyanoacrylate glues to seal wounds to the United States Food and Drug Administration (FDA). Soon afterward Dr. Coover's glue did find use in Vietnam--reportedly in 1966 cyanoacrylates were tested on-site by a specially trained surgical team, with impressive results."

      --
      moo.
    2. Re:Coming to a WalMart Near You! by cgenman · · Score: 2, Interesting

      I've had doctors tell me that if you have a bad wound in need of stitches but you don't have anything handy, superglue it. It dries fast and strong, and while it may not be terribly accurate it will stop the bleeding. And like the superglue that gets on your fingertips, it eventually goes away on it's own.

  6. WTF? by El · · Score: 2, Funny

    door latches that can be opened with a flashlight.
    Right... 'cause we all want a door that opens itself every morning when the sun comes up!

    --

    "Freedom means freedom for everybody" -- Dick Cheney

    1. Re:WTF? by Mavakoy · · Score: 3, Interesting

      Could be useful on farms, or if you have a dog in the house and don't want to crawl out of bed first thing!

  7. Reminds me of my old Speeder by YetAnotherName · · Score: 5, Funny

    I had one of those Star Wars Speeders that fit Luke and Ben Kenobi action figures as a kid. It was all plastic. I accidentally left it on the dashboard of my mom's car during a sunny day.

    Sure enough, light changed its shape irrevocably.

  8. clarfication by morcheeba · · Score: 5, Informative

    Just to clarify... this plastic changes shape in response to various wavelengths of light... not the quantity, as has been previously done. (Note - the older technology has been adapted for cell phones, too)

  9. For Slashdot Readers... by rookworm · · Score: 5, Funny

    This could be the ultimate cure for geeks. Simply wear special plastic goggles that restrict vision (and hence computer access) if wearer does not go outside.

    --
    The toad can't burp - and for some reason can't fart either, so it swells up and eventually explodes. --Anonymous Coward
  10. Sometimes the simplest things are the best... by Gadgetfreak · · Score: 5, Funny

    Personally, I'd like some self-adjusting miniblinds.

    --
    "No fair, you changed the outcome by measuring it!" - Professor Hubert J. Farnsworth
  11. Odd examples. by BigZaphod · · Score: 4, Interesting

    Why do these "gee whiz" stories about new tech or materials always have such strange example applications?

    "This material could one day lead to medical devices that build themselves inside a patient's body, or door latches that can be opened with a flashlight."

    Okay, the medical one isn't so bad (except, kinda dark in a body)... but a door latch that opens with a flashlight? Huh?

    How about...
    - Plastic flowers that open in the sunlight!
    - Sunglasses that automatically lower in front of your eyes!
    - Light-based transformer toys!
    - Gag sundials!

    Okay, maybe this is harder than it looks...

    1. Re:Odd examples. by rookworm · · Score: 2, Funny

      Chasitity belts!

      --
      The toad can't burp - and for some reason can't fart either, so it swells up and eventually explodes. --Anonymous Coward
    2. Re:Odd examples. by UserGoogol · · Score: 5, Funny

      You have to appreciate the mind of a scientist.

      Scientist1: Dude, look at this plastic. When it comes in contact with ultraviolet light, the plastic forms bonds with itself, causing it to change shape.

      Scientist2: Awesome! If you hit it with another frequency, the proccess reverses itself.

      Businessman: Hm. What sort of applications do you think this could have?

      Scientist2: App-li-kay-shuns?

      Scientist1: Uh, you could make toys out of it. Or... maybe like you could have it bend into... uh... medical things. For medicine.

      Businessman: I'm cutting your funding.

      Scientist1: WHY DON'T YOU LOVE ME?!?

      --
      "Never attribute to malice that which can be adequately explained by stupidity." -- Hanlon's Razor
  12. How about self tracking solar panels? by ZombieEngineer · · Score: 5, Interesting

    This could allow retail level solar panels to eek out the equivalent to an additional 2 hours of peak sunlight over a 12 hour period. Initially this would appear to be a 10% improvement but in reality it is closer to a 30% improvement (I will leave it as an exercise for the reader to integrate sin(x.pi/12) from 0 to 12 hours [flat panel on the ground with the sun passing directly overhead] to yield 6.28).

    I should imagine the cost of the plastic is going to be far less than the processed silicon for solar cells.

    da ZombieEngineer

  13. Other related work by karvind · · Score: 5, Informative
    Another field where MIT work can be useful is space antennae. Here an optical signal would initiate a sequence of changes in the shape, causing the antenna to refocus on a different point in space.

    OSU had developed light-tunable plastic magnets. Here the plastic material becomes 1.5 times more magnetic when blue light shines on it. Green light partially reverses that effect.

    Another interesting work is from PSU on PLZT, this new material shows a large piezoelectric effect in response to near-ultraviolet light. Piezoelectric materials convert electricity into mechanical energy -- movement. When an electric current is run through piezoelectric ceramic, the ceramic changes size -- it shrinks or expands. Certain ferroelectric materials exhibit stronger photovoltaic (light into electricity) effects. Combining these ferroelectrics with piezoelectrics (electricity into motion), researchers created a single material that would convert light directly into motion.

  14. perfect for the beach! by bobalu · · Score: 4, Funny

    They can stay smallish during the week so the lady doesn't get unwanted catcalls, then when she puts on a bikini - POP!

    Ah, plastics... truly better living through technology!

    --
    The revolution will NOT be televised.
  15. I have something similar. by KipCas · · Score: 3, Funny

    Well, my wife does. It can sort of shapeshift. It is plastic as well and if anybody but me or her see it it becomes a "Back Massager".

    --
    Turk: Let's play Steak. J.D.: What? Turk: Steak. The 1st person to finish their steak is the winner of Steak. -Scrubs
  16. So that explains it by _ph1ux_ · · Score: 4, Funny

    I have met some women who have faces made out of this stuff. Unfortunately I had to find out the hard way.

  17. Windows by phorm · · Score: 2, Interesting

    No, but we might want a window that does. Have it close up on a cold night and open to a warm summer morning to let the fresh air in...