Distributed electronics for improving the accuracy of sensing in harsh high temperature environments, such as aero-engine and down-well is a growing field, where reduced power input requirements in cabling and batteries is viewed a key enabler for accelerating the adoption of high temperature electronics. Although batteries are available that can operate up to 200°C, they offer limited life at high temperatures and are bulky, increasing the costs of deployment and maintenance. Cabling also adds weight and takes up space in limited access applications. Energy harvesting in-situ offers the opportunity to make a step change in the design of high temperature electronics modules and in expanding their possible range of applications; for example, in sensor systems for combustor and turbine monitoring in aero-engines.
This paper covers an assessment of MEMS vibration energy harvesting technology for high temperature sensing applications. MEMS devices based on the principle of parametric resonance, using AlN on Silicon have been designed and fabricated, along with sourcing of high temperature components for rectification, impedance matching and energy storage. The MEMS devices have been packaged into ceramic chip carriers and measured for energy output from a random vibration profile representative of an aerospace application. The measured output from the MEMS vibration energy harvester is capable of providing sufficient power to be of interest for autonomous sensing applications.
This paper reports on the performance of the MEMS vibration energy harvesting devices and their associated circuitry at room temperature and at temperatures of up to 150°C. The challenges remaining to develop robust energy harvesting devices that could be applied in aero-engine, down-well and other high temperature applications are described.
This work has been carried out under the Innovate UK supported project HI-VIBE, in a collaboration between GE Aviation Systems – Newmarket and the University of Cambridge.
Finite element based system simulation for piezoelectric vibration energy harvesting devices
