Fully Integrated High-Performance MEMS Energy Harvester for Mechanical and Contactless Magnetic Excitation in Resonance and at Low Frequencies

Abstract

Energy harvesting and storage is highly demanded to enhance the lifetime of autonomous systems, such as IoT sensor nodes, avoiding costly and time-consuming battery replacement. However, cost efficient and small-scale energy harvesting systems with reasonable power output are still subjects of current development. In this work, we present a mechanically and magnetically excitable MEMS vibrational piezoelectric energy harvester featuring wafer-level integrated rare-earth micromagnets. The latter enable harvesting of energy efficiently both in resonance and from low-g, low-frequency mechanical energy sources. Under rotational magnetic excitation at frequencies below 50 Hz, RMS power output up to 74.11 µW is demonstrated in frequency up-conversion. Magnetic excitation in resonance results in open-circuit voltages > 9 V and RMS power output up to 139.39 µW. For purely mechanical excitation, the powder-based integration process allows the realization of high-density and thus compact proof masses in the cantilever design. Accordingly, the device achieves 24.75 µW power output under mechanical excitation of 0.75 g at resonance. The ability to load a capacitance of 2.8 µF at 2.5 V within 30 s is demonstrated, facilitating a custom design low-power ASIC.

Emerging low-cost, large-scale photonic platforms with soft lithography and self-assembly

“…Furthermore, this has also been proven in integrated circuits and microelectromechanical systems (MEMS) [269,270] . Nanotechnology combined with MEMS has been widely used in optical devices [271,272] , portable electronic devices [273] , and energy [274,275] , leading to the development of new devices such as zero-power sensors.…”

Towards Robust Thermal MEMS: Demonstration of a Novel Approach for Solid Thermal Isolation by Substrate-Level Integrated Porous Microstructures

“…To achieve a stable vacuum inside the porous microstructure, films having a thickness of several micrometers can be deposited by standard MEMS chemical and physical vapor deposition processes. It has already been shown that, for example, silicon oxide can be deposited pinhole-free by PECVD on top of a porous 3D microstructure [ 19 , 21 ]. However, the (long-term) hermeticity of such sealings remains to be investigated.…”

“…Finally, the wafers are cleaned of any unwanted powder residues and are ready for further processing under standard MEMS cleanroom conditions. In previous work, the use of PowderMEMS structures for energy harvesting and zero-powder wakeup [ 18 , 19 ], permanent micromagnets and magnetic position detection [ 20 , 21 ], and the creation of liquid-cooled microscale inductor cores [ 22 ] has been presented.…”

A Review of Nonlinear Mechanisms for Frequency Up-Conversion in Energy Harvesting

“…The magnetic plucking principle has also been applied in electromagnetic [77] and mixed piezo-magnetic transduction [136], leading to patented ideas as well [137,138]. Additionally, Bodduluri et al [139] implemented magnetic plucking at the MEMS scale with an integrated process of the magnetic material deposition. [125] with the permission of Elsevier.…”