In the future, this elastic, organic, thin film, which produces electricity when stretched or compressed, could be used as a sensor, sewn into clothing, or even implanted in the human body. This would allow it to monitor activities, detect touches or power devices such as pacemakers.
The ability to convert mechanical movement into electrical charges is due to the rubber’s piezoelectric effect, a property long associated only with crystals. The trick behind it: the inner polarization of the rubber – a composite made of polar nanoparticles and an elastomer – changes as soon as it is mechanically deformed. In order to obtain a piezoelectric material, the Swiss EMPA researchers had to first give the rubber an internal polarization by means of a strong electric field. Once achieved, this orientation is "frozen" in place by cooling the material to room temperature.