Measurement method for assessing the power generation characteristics of piezoelectric energy transducers

摘要

There has been an increasing necessity for the development of power supply technologies for user-wearable subsystems, e.g., mobile phones and portable electronics. In particular, it is useful for these systems to use electrical power generated by human activities, e.g., walking [1] and thermal energy [2]. Some of these mechanisms have already been put into practical use as a power source for watches [3]. Piezoelectrics have been used for an ignition system in which input mechanical stress can generate high electric voltages. Piezoelectric materials could be, therefore, some of the most promising candidates for micro-device power generation. Mechanical-electrical transducer properties have yet not been fully clarified. Only qualitative comparisons between ceramic and polymer transducers have so far been reported [1], and the ceramic transducers were found to have some advantages in out-put power. Therefore our first objective was to build up a power transducer device using piezoelectric ceramics and also to measure its energy conversion efficiency.