Resonant Varifocal Micromirror with Piezoresistive Focus Sensor

Autor: Kenta Nakazawa, Takashi Sasaki, Hiromasa Furuta, Jiro Kamiya, Hideki Sasaki, Toshikazu Kamiya, Kazuhiro Hane
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Micromachines, Vol 7, Iss 4, p 57 (2016)
Druh dokumentu: article
ISSN: 2072-666X
DOI: 10.3390/mi7040057
Popis: This paper reports a microelectromechanical systems (MEMS) resonant varifocal mirror integrated with piezoresistive focus sensor. The varifocal mirror is driven electrostatically at a resonant frequency of a mirror plate to obtain the wide scanning range of a focal length. A piezoresistor is used to monitor the focal length of the varifocal mirror. The device is made of a silicon-on-insulator (SOI) wafer and a glass wafer. A mirror plate and a counter electrode are fabricated by a top silicon layer of the SOI wafer and on the glass wafer, respectively. The piezoresistor is fabricated by ion implantation on a supporting beam of the mirror plate. The stress variation of the beam, which is detected by the piezoresistor, correspond the focal length of the varifocal mirror. The focus length varies from −41 to 35 mm at the resonant frequency of 9.5 kHz. The focal length of the varifocal mirror is monitored by the piezoresistor in real time.
Databáze: Directory of Open Access Journals