Teijin and Yoshiro Prof. Tajitsu of Kansai University jointly developed a new plant-derived piezoelectric element expected to create a new and promising field in organic electronics. The new element can be mass produced more easily and at a lower cost than the existing elements based on ceramic materials. They put a thin film made of polylactate and a conductive resin to be used as electrode alternately. The new element extends about 2.5 times longer than lead zirconate titanate if the same voltage is applied. It is also rather suitable to create a large sheet. In addition, it is environment-friendly because it does not contain lead.
The new piezoelectric element will have a variety of new applications because it is thinner and softer than the existing piezoelectric elements besides being transparent. Wrapping a sheet made of the new element around the knee of an elderly person and changing the voltage applied to the sheet helps him walk comfortably. This is a new concept of walking aid device. Should it be stuck to a human body, it is possible to develop a system to charge a cardiac pacemaker using electricity created by the movements of breathing and walking. Should it be applied to a touch panel, the user can change the screen simply by changing the pressure to touch it. Teijin and the professor plan to put the new piezoelectric element into practical use in a few years.
A photo of the existing piezoelectric element. The newly-developed piezoelectric element is plant-derived. It is thinner and softer than the existing piezoelectric elements besides being environmentally friendly.