Re: Electrostatic actuators to move robots legs...

On 9/12/24 12:34, Jeff Layman wrote:

On 12/09/2024 10:45, Cursitor Doom wrote:

On Thu, 12 Sep 2024 05:00:38 GMT, Jan Panteltje wrote:
>

Artificial muscles propel a robotic leg to walk and jump:
  https://www.sciencedaily.com/releases/2024/09/240909113111.htm
>
quote:
  "
  The actuators are oil-filled plastic bags, similar to those used to
  make ice cubes.
  About half of each bag is coated on either side with a black electrode
  made of a conductive material.
  Buchner explains that "as soon as we apply a voltage to the electrodes,
  they are attracted to each other due to static electricity.
  ...
  "
And press the fluid out....
So electrostatic actuators!

>
How does that not violate thermodynamics? You seem to be getting useful
power from zero energy.

 How do little pieces of paper defy gravity when you put a charged comb near them? Isn't the energy supplied by rubbing the comb against some material to give it the charge to attract the paper? Where does the voltage come from which is applied to the bag electrodes?
 Didn't we discuss something like this not too long ago, or was it in another NG?
<https://en.wikipedia.org/wiki/Electrostatic_motor>
 

That was right here in s.e.d in July. And no, thermodynamics, or
rather conservation of energy is not violated. It never is.
I don't think that they can get useful amounts of work out of these
things. The Science Daily article is useless, as always, and I did
not bother to read the paper.
Jeroen Belleman