Abstract
Low-cost automotive laser scanners for environmental
perception are needed to enable the integration of
advanced driver assistant systems into all automotive
vehicle segments, which is a key to reduce the number of
traffic accidents on roads. Within the scope of the
Europeanfunded project MiniFaros, partners from five
different countries have been cooperating in developing a
small-sized low-cost time-of-flight-based range sensor.
An omnidirectional 360-deg laser scanning concept has
been developed based on the combination of an
omnidirectional lens and a biaxial large aperture MEMS
mirror. The concept, design, fabrication, and first
measurement results of a resonant biaxial 7-mm
gimbal-less MEMS mirror that is electrostatically
actuated by stacked vertical comb drives is described.
Identical resonant frequencies of the two orthogonal axes
are necessary to enable the required circle scanning
capability. A tripod suspension was chosen, since it
minimizes the frequency splitting of the two resonant
axes. Low-mirror curvature is achieved by a thickness of
the mirror of more than 500 ìm. Hermetic wafer-level
vacuum packaging of such large mirrors based on multiple
wafer bonding has been developed to enable a large
mechanical tilt angle of 6.5 deg in each axis. Due to the
large targeted tilt angle of 15 deg and because of the
MEMS mirror actuator having a diameter of 10 mm, a cavity
depth of about 1.6 mm has been realized.
Original language | English |
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Number of pages | 12 |
Journal | Journal of Micro/ Nanolithography, MEMS, and MOEMS |
Volume | 13 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2014 |
MoE publication type | A1 Journal article-refereed |
Keywords
- lidar
- microelectromechanical systems
- mirrors
- opticaldevices
- scanners
- scanning