Shock caging features for MEMS actuator structures
Caging structures are disclosed for caging or otherwise reducing the mechanical shock pulse experienced by MEMS device beam structures during events that may cause mechanical shock to the MEMS device. The caging structures at least partially surround the beam such that they limit the motion of the beam in a direction perpendicular to the beam's longitudinal axis, thereby reducing stress on the beam during a mechanical shock event. The caging structures may be used in combination with mechanical shock-resistant beams.
1. A microelectromechanical systems (MEMS) actuator, comprising:
a plurality of silicon beams; and
a silicon caging structure at least partially surrounding each of the plurality of silicon beams, wherein the silicon caging structure limits a maximum displacement of each of the plurality of silicon beams in a direction perpendicular to the silicon beam's length.
2. The MEMS actuator of claim 1 , wherein each of the plurality of silicon beams is between 1 and 7 millimeters long and between 10 and 70 micrometers wide.
3. The MEMS actuator of claim 1 , further comprising: a moving frame, the moving frame comprising at least a portion of the silicon caging structure; and wherein at least some of the plurality of silicon beams are directly coupled to the moving frame.