Large area piezoelectric impact sensors

Printed electronics is an active area of research which enables production of electrical devices on various substrates. The use of highly insulating materials and the employment of dielectric phenomena based on the piezo- and pyroelectric effect in polar insulators promise large area sensors useful in protection sensor systems to save pedestrians. In this paper we propose a car safety system based on printed piezo- and pyroelectric sensors. Their use in pedestrian saving systems is exemplified by a toy-car-demonstrator. The sensors are based on ferroelectric polymers, printed on flexible PET substrates. The piezoelectric coefficients of the printed ferroelectric polymer film are typically 25 pC/N, sufficient for impact detection in car crash situations. The sensor speed is very fast, enabling efficient protection mechanisms to safe the life of pedestrians. The simple and potentially low cost fabrication is advantageous in comparison to systems currently available on the market.