First autonomous wireless sensor node powered by a vacuum-packaged piezoelectric MEMS energy harvester

This paper describes the experimental characterization of piezoelectric harvesters with different dimensions. We present a record level of generated power of 85 ¿W obtained from an unpacked device. We have developed a wafer-scale vacuum package which shows a 100-200 fold increase in power output compared with packaged devices under atmospheric pressure. A wireless sensor node was fully powered by a piezoelectric harvester. The average power consumption was less than 10 ¿W while it was operating at 15 seconds duty cycle.