Piezoelectric MEMS generators fabricated with an aerosol deposition PZT thin film

Abstract

In this paper, we present the development of two piezoelectric MEMS generators, {3-1} mode and {3-3} mode, which have the ability to scavenge mechanical energy of ambient vibrations and transform it into useful electrical power. These two piezoelectric MEMS generators are of cantilever type made by a silicon process and which can transform mechanical energy into electrical energy through its piezoelectric PZT layers. We developed a PZT deposition machine which uses an aerosol deposition method to fabricate the high-quality PZT thin film efficiently. Our experimental results show that our {3-1} mode device possesses a maximum open circuit output voltage of 2.675 V P-P and a maximum output power of 2.765 μW with 1.792 V P-P output voltage excited at a resonant frequency of 255.9 Hz under a 2.5 g acceleration level. The {3-3} mode device possessed a maximum open circuit output voltage of 4.127 V P-P and a maximum output power of 1.288 μW with 2.292 V P-P output voltage at its resonant frequency of 214 Hz at a 2g acceleration. We also compared the output characteristics of both the {3-1} mode and the {3-3} mode piezoelectric MEMS generators which were both excited at a 2g acceleration level.

Characterizing Effective d31 Values for PZT from the Nonlinear Oscillations of Clamped-Clamped Micro- Resonators

“…With the ability to transform strain into an electric current through the direct piezoelectric effect and, by way of the converse piezoelectric effect, convert an applied electric field into stress, piezoelectric material is used to provide both sensing and actuation capabilities. Some examples of MEMS devices which utilize piezoelectric material that have recently been developed include contour-mode microresonators [1], shunt-type ohmic RF MEMS switches [2], MEMS generators [3], nano-robotics [4], and three-dimensional valveless micro-pumps [5].…”

Piezoelectric Thick Film Based on Bonding technologies for Energy Harvester

“…(14) A 5 μm PZT film for d 31 and d 33 mode MEMS generators was prepared by an aerosol deposition process. (23) The fabricated device under the d 31 mode generated a maximum output power of 2.765 μW at 255.9 Hz at an acceleration of 2.5g. In addition, a hydrothermal method (24) and a screen printing process (25) have been developed for thick films over 5 μm in thickness.…”

“…However, micro-energy harvesters are an alternative to solve this problem. They convert external mechanical energy into electrical energy by different conversion mechanisms, such as electrostatic, (1)(2)(3) electromagnetic, (4)(5)(6) triboelectric, (7)(8)(9) thermoelectric, (10)(11)(12) and piezoelectric (13)(14)(15)(16) mechanisms. Because piezoelectric harvesters have a simple structure, a high electromechanical coupling coefficient, no requirement for an external voltage source, and a long lifetime, they have been used in volume-limited wireless sensor nodes.…”

“…Many microfabrication processes for PZT thin or thick films for harvesters have been reported. (13,14,23) The common deposition processes for PZT and AlN using sol-gel and sputtering methods limit the thin-film thickness to within 1-2 μm. Liu et al demonstrated a MEMS microgenerator with a 3 μm PZT film deposited by the sol-gel process, which generated a power of 19.4-51.3 nW from 30 to 47 Hz at 1.0g.…”

Fabrication and Characterization of d33 Mode (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) Energy Harvester

“…Compared with other materials, the PMN-PT material exhibits outstanding piezoelectric properties that considerably surpass those of PZT ceramics by a factor of 4 to 5. (18) In addition to the optimization and selection of piezoelectric materials, some micromachining processes for thin and thick piezoelectric films have been proposed and developed, such as solgel, (5) aerosol, (19) and screen-printing (20) techniques. The thickness or piezoelectricity of the films formed by these methods is limited and very poor.…”