Magnetofluidic accelerometer with capacitive sensing of inertial body position
First Claim
1. A method of measuring acceleration comprising:
- suspending an inertial body using a magnetized magnetic fluid, wherein the inertial body is disk-shaped and includes two electrodes that cover substantially the entire upper and lower surfaces of the disk respectively, and additional electrodes on a curved side surface of the disk that have the shape of a curved surface,wherein the magnetic fluid is magnetized using a plurality of magnets oriented generally along an axis of symmetry of the inertial body;
measuring a change in capacitance generated by displacement of the inertial body due to acceleration; and
calculating the acceleration based on the capacitive voltage change between the two electrodes and the additional electrodes, and external electrodes.
4 Assignments
0 Petitions
Accused Products
Abstract
An accelerometer includes an inertial body; a magnetized fluid holding the inertial body in suspension; and a plurality of capacitive elements, each forming a capacitor with the inertial body. A displacement of the inertial body produces a change of capacitance of the capacitive elements that is indicative of acceleration. The capacitive elements include at least two capacitive elements per side of the accelerometer. A housing encloses the inertial body and the magnetized fluid, and the plurality of capacitive elements are mounted on the housing. The housing can be cylindrical shaped, rectangular shaped and tetrahedral-shaped. The inertial body can include a disk-shaped magnet, an annular-shaped magnet, or be non-magnetic, or be weakly magnetic. The acceleration can be linear acceleration, angular acceleration, or three components of angular acceleration and three components of linear acceleration. A plurality of magnets magnetize the magnetic fluid.
-
Citations
27 Claims
-
1. A method of measuring acceleration comprising:
-
suspending an inertial body using a magnetized magnetic fluid, wherein the inertial body is disk-shaped and includes two electrodes that cover substantially the entire upper and lower surfaces of the disk respectively, and additional electrodes on a curved side surface of the disk that have the shape of a curved surface, wherein the magnetic fluid is magnetized using a plurality of magnets oriented generally along an axis of symmetry of the inertial body; measuring a change in capacitance generated by displacement of the inertial body due to acceleration; and calculating the acceleration based on the capacitive voltage change between the two electrodes and the additional electrodes, and external electrodes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method of measuring acceleration comprising:
-
suspending a non-magnetic object using a fluid, wherein the non-magnetic object is disk-shaped and includes two electrodes that cover substantially the entire upper and lower surfaces of the non-magnetic object respectively, and additional electrodes on a curved side surface of the non-magnetic object that have the shape of a curved surface; generating a magnetic field within the fluid using a plurality of magnets oriented generally along an axis of symmetry of the non-magnetic object; detecting a capacitance change between the two electrodes and the additional electrodes and external electrodes due to a change in position of the object as a result of acceleration; and calculating the acceleration as a function of the control of the magnetic field.
-
-
11. An accelerometer comprising:
-
an inertial body that is disk-shaped and includes two electrodes that cover substantially the entire upper and lower surfaces of the disk respectively, and additional electrodes on a curved side surface of the disk that have the shape of a curved surface; a magnetized fluid holding the inertial body in suspension, wherein the fluid is magnetized using a plurality of magnets oriented generally along an axis of symmetry of the inertial body; and a plurality of external electrodes, each forming a capacitor with the electrodes of the inertial body, wherein a displacement of the inertial body produces a change in capacitance of the capacitors, the change being indicative of acceleration. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
-
-
26. An accelerometer comprising:
-
a magnetic inertial body that is disk-shaped and includes conductive coatings that cover substantially the entire upper and lower surfaces of the disk respectively, and additional separate conductive coatings on a curved side surface of the disk that have the shape of a curved surface; a magnetic fluid in contact with the inertial body, wherein the magnetic fluid is magnetized using a plurality of magnets oriented generally along an axis of symmetry of the inertial body; and a plurality of external electrodes arranged around the inertial body, each forming a capacitor with the respective conductive coating on the inertial body, wherein a displacement of the inertial body changes a capacitive reactance of the capacitors, the change being indicative of acceleration.
-
-
27. An accelerometer comprising:
-
a housing incorporating a stretchable membrane; an inertial body within the housing, the inertial body being disk-shaped and includes conductive coatings that cover substantially the entire upper and lower surfaces of the disk respectively, and additional separate conductive coatings on a curved side surface of the disk that have the shape of a curved surface; a magnetic fluid in contact with the inertial body, wherein the magnetic fluid is magnetized using a plurality of magnets positioned generally around an axis of symmetry of the inertial body; a plurality of sensors sensing a change in position of the inertial body due to acceleration, the sensors sensing a change in capacitance of capacitors formed by the conductive coatings and external electrodes.
-
Specification