By developing a new organic composite that changes shape with minimal electrical input, researchers at Penn State have overcome a barrier to artificial muscles and provided a candidate material for everything from smart skins to miniscule drug pumps.

“Electroactive polymers have been around for a long time, but the energy input required for them to do enough work to be of value was very high,” says Dr. Qiming Zhang, a professor of electrical engineering at Penn State. “With this new composite we have reduced the voltage to one tenth that previously needed.”

Electroactive polymers are simply polymers that can undergo controlled changes in such things as charge distribution and shape. This makes the materials ideally suited to form such things as actuators, sensors and flexible displays.

For such things as artificial muscles, electroactive polymers need high flexibility and low voltage — they should undergo large shape changes with minimal electrical input.

In the September 19, 2002 issue of the journal Nature, Zhang and colleagues report creating an electroactive polymer that fits the profile — low voltage, and nearly as flexible as a rigid plastic bag.

Artificial muscles could be made from thin, stacked layers of the material. For transportation and other applications, the polymer could allow for smart skin that reduces drag. And the material’s ability to pulse with an electric charge could allow for the production of miniscule drug pumps for people with diabetes and other conditions that require regular dosages of medication.