Piezoelectric polymer films as power converters for human powered electronics

Piezoelectric polymer film material allows for conversion of mechanical energy into electrical energy that can be used for supplying electronic devices. While this method does not allow obtaining large useful power, recent advances in electronic technology, in particular wide availability of submicron low-power CMOS processes, have made feasible the idea of using piezoelectric polymers as power converters for human powered electronics. This concept allows to overcome the necessity of using battery as a power source, which is one of the main obstacles to widespread adoption of wearable computing devices. Of particular interest is harvesting energy from walking, which can be achieved by using piezoelectric polymers. In this paper maximum power has been calculated that can be drawn from walking energy owing to application of the copolymer polyethylene–polypropylene (PE–PP) shoe insole. The amount of electric energy obtained from a PE–PP foil of a thickness of 11 μm for a single step of a duration of 1 s – that is equivalent to a frequency of 1 Hz – amounts to 340 nJ.