Electrostatic actuators to move robots legs...

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!