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Objects floating in Ferrofluid

  1. Apr 18, 2013 #1
    Hi, Ive been thinking about ferroufluid and its application and whether anybody would be able to answer my questions.

    Is it denser or lighter than water. I know oil floats but it has iron in it.

    Surface tension of it. Reason I am asking about the surface tension is that I was wondering, if i managed to find an object that would float in the ferrofluid by being less dense and buoyant. And that I managed to suspend it in mid air using electromagnets( coils wrapping around it, and i placed this less dense object under neath the ferrofluid or in the side, would it float to the top.

    An example of this eqquipment would be a clear plastic container (size of a mug) with ferrofluid inside; with coils of wire hooked up to a battery, wrapped around the container. This container would have a closable hole in the bottom to place the object in. I belive when the coil is powered that the ferrofluid would hover. I would then open the hole in the bottom, push the object in and close the hole, then deactivating the coil, causing the object to float to the top.

    Thanks for reading. and appologies for any grammar mistakes.
  2. jcsd
  3. Apr 18, 2013 #2

    Simon Bridge

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    Depends - you can make a ferro-fluid with a wide range of materials and solid loadings. Densities usually run 0.81 to 3.4 g/cm^3. In the presence of a magnetic field effective densities as high as 20 g./cm^3 can be achieved.

    While magnetized, I'd imagine objects would be described as "bouncing off" most commercial ferro-fluids rather than "floating" in it.

    Is the idea that you levitate the fluid, leaving a gap under it, a hollow ball falls into the gap, you drop the fluid onto the ball, the ball floats to the surface, where is pops off to repeat the cycle?
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