Piezoelectric energy microgenerators are devices that generate continuously electricity when they are subjected to varying mechanical strain due to e.g. ambient vibrations. This paper presents the mathematical analysis, modelling and validation of a miniaturized piezoelectric energy harvester based on ambient random vibrations. Aluminium nitride as piezoelectric material is arranged between two electrodes. The device design includes a silicon cantilever on which AlN film is deposited and which features a seismic mass at the end of the cantilever. EulerBernoulli energy approach and Hamilton's principle are applied for device modeling and analysis of the operation of the device at various acceleration values. The model shows good agreement with the experimental findings, thus giving confidence into model. Both mechanical and electrical characteristics are considered and compared with the experimental data, and good agreement is obtained. The developed analytical model can be applied for the design of piezoelectric microgenerators with enhanced performance.
List of symbolsL Length of cantilever beam (m) B Width of cantilever beam (m) H Thickness of structural layer (m) T Thickness of piezoelectric layer (m) V Voltage across piezoelectric element (m) Z Coordinate parallel to beam thickness (m) X Coordinate parallel to beam length or axial coordinate (m) T k Kinetic energy (J) U Internal energy (J) W e Electrical work (J) W External work (J) q s Density of structural layer (kg m -3 ) q p Density of piezoelectric layer (kg m -3 ) U Displacement (M) S Applied strain (None) T Developed stress (Pa) EElectric field (V m -1 ) DElectric displacement (C m -2 ) dV s Differential volume of structural layer (m 3 ) dV p
We demonstrate multi-layer silicon-oxy-nitride (SiON) waveguides as a platform for broadband tunable phase-matching of second-order nonlinear interactions arising at material interfaces. Second-harmonic generation (SHG) is measured with a 2 ps pulsed pump of 1515-1535 nm wavelength, where 6 nW power is generated by an average pump power of 30 mW in a 0.92 mm long device. The wavelength acceptance bandwidth of the SHG is as broad as 20 nm due to the low material dispersion of SiON waveguides. The waveguide structure provides a viable method for utilizing second order nonlinearity for light generation and manipulation in silicon photonic circuits. V
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.