Enhancing the electromechanical behavior of a flexible polymer

Qiming Zhang, distinguished professor of electrical engineering, led a team of researchers to develop a robust piezoelectric material that can convert mechanical stress into electricity.
Credit: Tyler Henderson/Penn State

Piezoelectric materials convert mechanical stress into electricity, or vice versa, and can be useful in sensors, actuators and many other applications. But implementing piezoelectrics in polymers — materials composed of molecular chains and commonly used in plastics, drugs and more — can be difficult, according to Qiming Zhang, distinguished professor of electrical engineering.

Zhang and a Penn State-led team of interdisciplinary researchers developed a polymer with robust piezoelectric effectiveness, resulting in 60% more efficient electricity generation than previous iterations. They published their results today (Mar. 25) in Science. 

“Historically, the electromechanics coupling of polymers has been very low,” Zhang said. “We set out to improve this because the relative softness of polymers makes them excellent candidates for soft sensors and actuators in a variety of areas, including biosensing, sonar, artificial muscles and more.”

To create the material, the researchers deliberately implemented chemical impurities into the polymer. This process, known as doping, allows researchers to tune the properties of a material to generate desirable effects — provided they integrate the correct number of impurities. Adding too little of a dopant could prevent the desired effect from initiating, while adding too much could introduce unwanted traits that hamper the material’s function.