Hydraulic controlled polyester-based micro adaptive mirror with adjustable focal length
Currently micro-electromechanical systems (MEMS) technology is creating micro-mirrors for applications such as scanning and adaptive optics. A 0.5 mu m thin, reflective polyester sheet is used to create a 950 mu m diameter flexible mirror that is capable of changing its concavity. A system that consists of electrical circuits and LabVIEW interfaces were used to control the mirror. This paper presents a micro-mirror that is fabricated from a 0.5 pm thin, reflective polyester sheet clamped with aluminum disks. An electromagnetic plunge actuator controls the pressure beneath the mirror to change the curvature of the mirror. The focal point of the micro-mirror ranges from approximately infinity to 3.5 turn. This range is much wider than the ranges that are typical of MEMS mirrors. The curvature of the micro-mirror can be altered at a maximum observable frequency of about 15 Hz. The micro-mirror center depth movement is at increments of approximately 2 mu m and the focal length increment of change is approximately 5 mm. The mirror is capable of dynamically focusing on objects at a distance of 6 cm to longer than 7 m away from the mirror. (c) 2007 Elsevier Ltd. All rights reserved.
hydraulic control micro-mirror adaptive optics micro devices electro-mechanical systems polyester reflective film piezoelectric electromagnetic actuation and image focusing