Micro-Power Scavenging from Multiple Heterogeneous Piezoelectric and RF Sources

摘要

Since power harvesting applications are often constrained by the low levels of power available from individual energy transducers, it is essential for energy converters to efficiently deal with multiple independent and heterogeneous sources. This paper will present two actively controlled power conversion schemes able to deal with multiple piezoelectric and radio-frequency (RF) energy sources. Both converters are based on active control and make use of an ultra-low power standard microcontroller unit. The intrinsic power consumption of the harvesters are respectively 5.5 and 6.8 μW per source. The power harvesters were characterized with commercial piezoelectric transducers and with a custom designed rectenna. The achieved values of harvested power of tens of μW show that active control boosts performance of at least +41% as a worst case at the expense of a negligible intrinsic power consumption.