Harvesting Ambient Environmental Energy for Wireless Sensor Networks: A Survey

Table 5

The structures and characteristics of piezoelectric transducers.

Piezoelectric transducers	Characteristics
	A highest power can be generated under lower excitation frequencies and load resistances, widely used in cantilever beam structure
	Variable range of resonant frequency: 5 Hz~100 Hz, can be used in various configuration such as cantilever beam and end-end clamped beam
	Similar to bimorph but easier mounting, suitable for wide bandwidth, and widely used in cantilever beam structure
	Flexible, both d31 and d33 modes practicable, suitable for low strain and high frequency application, large area coverage, and can be used as a bimorph component
	Suitable for the application of low frequency (~10 Hz) and large uniaxial stress, easy mounting
	Ability to generate a higher output voltage in the given stress level, can be stacked to amplify output voltage
	Ability to withstand high stress, high output charge level, and adjustable resonance frequency