Could a substance that looks a little bit like hair-gel be used to create artificial muscle in life-like robots? PhD student Daniel Hutchinson from the University of Otago thinks so, and is working on creating polymer gel actuators in the laboratory.
An actuator is any device which converts energy into motion. Many devices use actuators, such as fans, pumps and artificial muscles. For example, in an electric fan heater, the actuator is the electric motor which converts electricity into the rotational motion of the fan.
A polymer gel consists of a criss-cross network of long polymer strands, with cavities between them. Like a sponge, these cavities allow the gel to absorb liquid, causing the gel to expand in size. When the liquid is removed, the gel shrinks back to its original size. A polymer gel actuator is created when an expanding and contracting gel is connected to a device which allows work to be done to, such as a piston. Using chemical reactions, Daniel Hutchinson can expand and contract the polymer gels he has created, with potential for these gel actuators to be applied as artificial muscles or as chemical sensors.