Microfabricated torsional cantilevers for sensitive force detection
First Claim
Patent Images
1. A compact, low mass force detector, comprising:
- a microfabricated support beam having first and second ends mounted to a substrate;
a moment arm extending from said support beam, said moment arm and said support beam being generally perpendicular to each other and coplanar, said moment arm being comprised of a rigid grid of microfabricated beams and being responsive to a force applied thereto to produce a corresponding torsional force on said support beam;
motion control means for said moment arm; and
means for measuring said force applied to said moment arm.
7 Assignments
0 Petitions
Accused Products
Abstract
A torsional cantilever is microfabricated for reduced size to increase its resonance frequency, increase its scanning speed, and permit fabrication of large numbers in an array to provide parallel scanning. The cantilever may incorporate a tip for highly sensitive force detection. The device preferably includes a cantilever arm and a counterbalance mounted on opposite sides of a laterally extending torsional beam fixed at its outer ends. Sensors detect rotation of the cantilever arm and may provide control of sensor locator through a feedback loop.
138 Citations
35 Claims
-
1. A compact, low mass force detector, comprising:
-
a microfabricated support beam having first and second ends mounted to a substrate; a moment arm extending from said support beam, said moment arm and said support beam being generally perpendicular to each other and coplanar, said moment arm being comprised of a rigid grid of microfabricated beams and being responsive to a force applied thereto to produce a corresponding torsional force on said support beam; motion control means for said moment arm; and means for measuring said force applied to said moment arm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
-
-
17. A force sensor, comprising:
-
a single-crystal silicon substrate; a torsionally-mounted cantilever including a moment arm and a support beam formed from said substrate and integral therewith, said cantilever moment arm being moved about said support beam with respect to said substrate in response to a force to be measured; and detector means including plural stationary electrode fingers on said substrate capacitively coupled to plural movable electrode fingers on said moment arm and interleaved with said stationary fingers for detecting motion of said moment arm. - View Dependent Claims (18, 19, 20, 21, 22)
-
-
23. A force sensor comprising:
-
a single-crystal silicon substrate; a torsionally-mounted cantilever including a moment arm, a counterweight, and a support beam formed from and integral with said substrate, said moment arm and said counterweight being coplanar with, perpendicular to, and extend in opposite directions from said support beam, and are movable with respect to said substrate, said cantilever arm being movable with respect to said substrate in response to a force to be measured to twist said support beam and wherein said cantilever is fabricated from said substrate in the form of single crystal silicon beams having cross-sectional aspect ratios of about 10 to 1, to provide mechanical rigidity in the direction of forces applied to said moment arm; and
detector means for detecting said motion. - View Dependent Claims (24, 25, 26, 27)
-
-
28. A force sensor, comprising:
-
a single-crystal silicon substrate; a movable frame carried by said substrate; a torsionally-mounted cantilever including a moment arm and a support beam, said support beam including first and second ends secured to said frame, said cantilever moment arm being moved about said support beam with respect to said frame in response to a force to be measured; and detector means for detecting motion of said moment arm. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35)
-
Specification