Microelectromechanical system sensor and method for using
View Patent ↗According to some embodiments, an apparatus includes a movable portion through which a sensing current is to be conducted. The movable portion might comprise, for example, a beam or plate suspended above a well in a Microelectromechanical System (MEMS) substrate. The apparatus may also include a sensing portion coupled to the movable portion, and the movable portion and/or sensing portion may move in a direction normal to the substrate in response to a magnetic field.
1. An apparatus, comprising:
a substrate having a surface;
a fixed comb mounted to the substrate and disposed generally parallel to the substrate surface;
a movable portion through which a sensing current is to be conducted; and
a comb-like sensing portion coupled to the movable portion and interleaved with the fixed comb, wherein the movable portion moves in a direction normal to the substrate surface in response to a magnetic field to produce a measurement resulting from movement of fingers of the sensing portion with respect to the fixed comb in the normal direction.
2. The apparatus of claim 1 , wherein the substrate is associated with a microelectromechanical system wafer and the movable portion is positioned substantially parallel to the substrate surface.
3. The apparatus of claim 1 , wherein the strength of the magnetic field is to be measured based on a piezoresistance change associated with the sensing portion.
4. The apparatus of claim 1 , wherein the apparatus is a sensor in an array of sensors.
5. The apparatus of claim 1 , wherein the apparatus is at least one of: (i) a magnetic field sensor, and (ii) an electrical current sensor.
6. The apparatus of claim 1 , wherein the suspended plate has a first conducting path and a second conducting path.
7. The apparatus of claim 6 , wherein the sensing current is to move through the two paths in a single direction.
8. The apparatus of claim 6 , wherein the sensing current is to move through the two paths in opposite directions.
9. The apparatus of claim 1 , wherein the strength of the magnetic field is to be measured based on a change in capacitance between the sensing comb and the fixed comb.
10. The apparatus of claim 1 , wherein the strength of the magnetic field is to be measured based on a quality factor change between the sensing comb and the fixed comb.
11. The apparatus of claim 10 , wherein the change in quality factor is determined in connection with at least one of: (i) a resonant frequency, (ii) mutual inductance coupling, and (iii) a mutually inductive voltage.
12. An apparatus, comprising:
a fixed comb;
a movable portion through which a sensing current is to be conducted; and
a comb-like sensing portion coupled to the movable portion and interleaved with the fixed comb, wherein the movable portion moves in response to a magnetic field in two orthogonal directions including a direction normal to a substrate to produce a measurement resulting from movement of fingers of the sensing portion with respect to the fixed comb in the normal direction.
13. The apparatus of claim 12 , wherein the substrate is associated with a microelectromechanical system wafer.
14. The apparatus of claim 12 , wherein the strength of the magnetic field is to be measured based on at least one of: (i) a change in capacitance, (ii) a quality factor change, and (iii) a piezoresistance change.
15. The apparatus of claim 14 , wherein the apparatus is at least one of: (i) a magnetic field sensor, and (ii) an electrical current sensor.
16. A method of sensing an electromagnetic value, comprising:
providing a sensing current through a movable portion of a sensor, the movable portion comprising a comb-like portion interleaved with a fixed comb that is mounted to a substrate and generally parallel to a surface of the substrate; and
measuring an electrical characteristic of the sensing portion coupled to the movable portion when the movable portion moves in a direction normal to the substrate surface in response to a magnetic field to produce a measurement resulting from movement of fingers of the sensing portion with respect to the fixed comb in the normal direction.
17. The method of claim 16 , wherein electrical characteristic is associated with at least one of: (i) a change in capacitance, (ii) a quality factor change, and (iii) a piezoresistance change.
18. The method of claim 17 , further comprising:
determining, based on the measured electrical characteristic, at least one of: (i) a magnetic field value, and (ii) an electrical current value.
19. A system, comprising:
a substrate having a surface;
a fixed comb mounted to the substrate and disposed generally parallel to the substrate surface;
a microelectromechanical system sensor, including:
a movable portion through which a sensing current is to be conducted, and
a comb-like sensing portion coupled to the movable portion and interleaved with the fixed comb, wherein the movable portion moves in a direction normal to the substrate surface in response to a magnetic field to produce a measurement resulting from movement of fingers of the sensing portion with respect to the fixed comb in the normal direction; and
a sensor dependent device.
20. The system of claim 19 , wherein the sensor dependent device is associated with at least one of: (i) a security device, (ii) a medical device, (iii) an electrical controller, (iv) a power distribution device, (v) a power meter, (vi) a circuit breaker, (vii) a consumer device, and (viii) a motor control device.