Microelectromechanical system with balanced center of mass
View Patent ↗MEMS and fabrication techniques for positioning the center of mass of released structures in MEMS are provided. A MEMS device includes a substrate and a released structure connected to the substrate via a flexure. The released structure includes a frame rotatable with respect to the substrate, and an elongate first member having a longitudinal axis extending perpendicularly from an undersurface of the frame and a free end remote from the frame. A recess is formed in an end face of the free end. The recess has a longitudinal axis substantially parallel to the longitudinal axis of the first member and a transverse area smaller than an area of the end face.
1. A MEMS, comprising:
a substrate; and
a released structure connected to the substrate via a flexure, the released structure comprising:
a frame rotatable with respect to the substrate, and
an elongate first member having a longitudinal axis extending perpendicularly from an undersurface of the frame and a free end remote from the frame,
wherein the first member comprises a recess formed in an end face of the free end, the recess having a longitudinal axis substantially parallel to the longitudinal axis of the first member, and the recess having a transverse area smaller than an area of the end face.
2. The MEMS of claim 1 , wherein the recess has a longitudinal length equal to at least 10% of the first member's longitudinal length.
3. The MEMS of claim 2 , wherein a sidewall defining the first member's longitudinal length is independent of the longitudinal length of the recess.
4. The MEMS of claim 1 , wherein the released structure further comprises a stage pivotally coupled to the frame, the stage comprising a second member extending perpendicularly from an undersurface of the stage and having a free end remote from the stage.
5. The MEMS of claim 4 , wherein a second recess is formed in a face of the free end of the second member, the second recess having a longitudinal axis substantially parallel to a longitudinal axis of the second member, and the second recess having a transverse area smaller than an area of the face the free end of the second member.
6. The MEMS of claim 5 , wherein a surface area between the first member and the second member is independent of the longitudinal length of either the first or second recess.
7. The MEMS of claim 1 , wherein the first member comprises a plurality of recesses in the face of the free end.
8. The MEMS of claim 7 , wherein each of the plurality of recesses has a longitudinal axis substantially parallel to a longitudinal axis of the first member.
9. The MEMS of claim 1 , wherein the recess is tapered along the longitudinal axis.