Title:

Micro Piezoelectric Energy Harvester Fabricated with PZT Thin-film Using Aerosol Deposition Method

Abstract

Internet of Thing (IoT) devices has been recognized as next thing big in semiconductor
industry. Before 2020, there will be billions of connected intelligent devices linked with
internet and interact with internet of people. For mobile devices and IoT devices in remote
area or installed in difficult to access locations, battery is usually the only solution to power
this kind of devices. However, the service and matainanace costs for battery operated devices
are usually high. Nevertheless, energy harvesting technologies to havest energy from ambient
enviroment is therefore promising to replace batteris in these devices.
The piezoelectric micro energy harvesters (PMEH) or so called MEMS generators which can
scanvege power from ambient vibrations has been an important research topic in the past
decade. With the advancement of PMEH and with the SOC (system on chip) or SIP (system
in package) technologies, it is possible to see a self-powered IC (integrated circuit) in near
future. The performance, including the output votlage and output power for PMEHs has been
steadily improved in the last decade. With the high quality PZT (lead zirconate titanate) thinflrm
deposited with a home-made aerosal deposition chamber and the stainless subtrated
based micro fabrciation processes, high output power with highly reliable PMEHs has been
succesfully fabricated. The output power of a cantilever type bi-morph PMEHs with a
dimension of 9×6 mm chip aera has been acheived 425μW under a 1g vibration level at
143.25Hz.
In this presenation, the aerosal deposition method and the analsysis of the PZT thin-films
deposited will be detailed. The fabrication process and design consideration of using stainless
steel substrates instead of conventional silicon substrates will also be presented. The failure
modes of PMEHs under high vibration levels will also be discussed. A self-powered SSHI
(synchoronized swichting on inductors) non-linear interafacing circuit has also been sucefully
integrated with the PMEH. The results and considerations of the non-linear interafcing circuit
and PMEH integration will also be presented.

Biography

Wen-Jong Wu is currently Professor with Department of Engineering Science and Ocean Engineering, National Taiwan University, Taipei, Taiwan.  Wen-Jong Wu got his Ph.D degree in Institute of Applied Mechanics from National Taiwan University.  He joined Department of Engineering Science and Ocean Engineering, National Taiwan University as Assistant Professor since 2003, has been Associate Professor since 2010, and has been Professor since 2014.  From 2007 to 2008, he was with Department of Mechanical and Aerospace Engineering, Cornell University, NY USA as a visiting assistant professor.  He is currently associate editor of Smart Materials and Structures and International Journal of Distributed Sensor network. His research interests are in piezoelectric power transducer, vibration energy harvesting, wireless sensor networks, and flexible electronics.