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I Is there any smart material that gets lighter/heavier?

  1. Sep 15, 2016 #1
    Hi PF,

    This could possibly be through a change in size or density...Maybe even programmable matter. I've tried some googling but haven't found anything on actually changing the weight through putting a current through something. It would be extremely useful for my personal hobby. Even through a change in temperature, not necessarily a current would maybe be acceptable. It doesn't have to be anything too big, just a few millimeters/centimeters in size, but some sort of material or substance that can change its weight (preferably without expanding too much, but that would still be interesting to) when a current runs through it or the temp changes..
    If you guys have heard of anything like this, let me know!
    Thanks :)
     
  2. jcsd
  3. Sep 15, 2016 #2

    berkeman

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    Staff: Mentor

    You could use a solenoid to increase or decrease the volume of an enclosure, or you could use memory metal to do a similar thing. What is the application?

    https://en.wikipedia.org/wiki/Shape-memory_alloy

    :smile:
     
  4. Sep 15, 2016 #3

    jbriggs444

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    Science Advisor

    Hot air balloons.
     
  5. Sep 15, 2016 #4

    I'm looking to have some sort of material that I can make lighter/heavier on demand to create a weight imbalance in my device (it isn't very large-no more than a few centimeters).
     
  6. Sep 15, 2016 #5

    billy_joule

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    Science Advisor

    Many materials change density with current (eg a lightbulb filament) but changing weight would break the law of conservation of mass.
    https://en.m.wikipedia.org/wiki/Conservation_of_mass
    What you want can't be done.

    If you explain exactly what you are trying to do (with diagrams perhaps) and why, we may have more realistic solutions.
     
  7. Sep 15, 2016 #6

    berkeman

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    Staff: Mentor

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