A micromachined low-frequency piezoelectric harvester for vibration and wind energy scavenging

Abstract

To efficiently scavenge ambient vibration energy and wind energy at the same time, a low-frequency piezoelectric harvester was designed, fabricated and tested. A lumped-parameter model of the cantilevered piezoelectric energy harvester with a proof mass was established and the closed-form expressions of voltage and power on a resistance load under base acceleration excitation were derived. After effects of the lengths of the proof mass and electrodes on output power were analyzed, a MEMS harvester was optimally designed. By using aluminum nitride as piezoelectric layer, a MEMS energy harvester was fabricated with bulk micromachining process. Experimental results show that the open-circuit frequency of the MEMS harvester is about 134.8 Hz and the matched resistance is about 410 k . Under the harmonic acceleration excitation of ± 0.1 g, the maximum output power is about 1.85 μW, with the normalized power density of about 6.3 mW cm −3 g −2 . The critical wind speed of the device is between 12.7 and 13.2 m s −1 when the wind direction is from the proof mass to the fixed end of the cantilever. The maximum output power under 16.3 m s −1 wind is about 2.27 μW.

Energy Harvesting Research: The Road from Single Source to Multisource

“…The contact/impact and contactless configurations adopt similar concepts of conventional wind turbines while replacing the electromagnetic generator with piezoelectric energy harvesters. Beside these, there are other configurations of galloping and piezoelectric polymers/films/cantilevers/membrane excited by the direct blowing force or vortex induced by wind. These configurations introduce some novel concepts such as energy harvester trees or grass .…”

Impact-Based Electromagnetic Energy Harvester with High Output Voltage under Low-Level Excitations

“…The electromagnetic, piezoelectric, or electrostatic transduction mechanisms have been used by VEHs to convert mechanical energy into electricity [17][18][19][20][21][22][23][24]. The advantages of EMVEHs, such as high power density and high reliability, make them attractive in real applications.…”

A Wind Energy Powered Wireless Temperature Sensor Node

“…In recent years, a variety of energy harvesters have been developed to scavenge ambient energy sources, such as solar, vibration or wind energy, to power wireless sensor nodes. Vibration energy harvesters have received much attention due to the ubiquitous presence of the vibration in the environment [ 1 , 2 , 3 , 4 , 5 ]. In the past few years, more and more efforts have been devoted to wind energy harvesters [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ].…”

“…It is difficult to miniaturize these devices by MEMS technology. The other is flow-induced vibration or wind-induced vibration energy harvesters [ 1 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ], whose structures are relatively simple and can be miniaturized by micromachining process. The airflow causes beams or diaphragms to vibrate, and the vibration energy is then converted into electrical energy based on mechanical-to-electrical conversion mechanisms such as piezoelectric effect, electromagnetic induction or electrostatic induction.…”