Abstract: A method of measuring acceleration includes suspending an inertial body using a magnetic fluid; generating a magnetic field within the magnetic fluid; modulating the magnetic field to counteract a change in position of the inertial body relative to sources of the magnetic field due to acceleration; and calculating the acceleration based on the modulation. The calculating step derives the acceleration based on an amount of current through drive coils required for the modulation. The acceleration includes linear acceleration and/or angular acceleration. The drive coils include permanent magnets, electromagnets, or a combination of a permanent magnet and an electromagnet. Sensing coils can be used for detecting the displacement of the inertial body. Each sensing coil can be positioned substantially within a corresponding drive coil. The inertial body can be non-magnetic, weakly magnetic, or have a ferromagnetic coating.

Abstract: A computer input device includes a magnetized fluid and an inertial body within the magnetized fluid. A signal converter provides angular acceleration information based on behavior of the inertial body. The computer input device can be attached to a Virtual Reality Suit, or can be used to control computer-generated graphical objects. The inertial body can be non-magnetic. The body can be solid or hollow. Electromagnets and/or permanent magnets can be used for magnetizing the fluid. Magnetic coils sense the changes in the magnetic flux lines. Signals from the magnetic coils are used by the signal converter to calculate the angular acceleration. A housing encloses the magnetized fluid and the inertial body.

Abstract: A sensor includes a housing and a magnetic fluid within the housing that incompletely fills the housing. An inertial body is in contact with the magnetic fluid. Displacement of the inertial body relative to the magnetic fluid is indicative of acceleration on the housing. The acceleration includes linear and/or angular acceleration. The inertial body can be an air bubble, or a dissimilar liquid. A plurality of magnets are mounted on the housing, wherein the magnetic fluid is positioned in droplets between the magnets and the inertial body. The magnetic fluid can be a single droplet between each magnet and the inertial body, or multiple droplets between each magnet and the inertial body. The remaining volume in the housing can be filled with a non-magnetic fluid.

Abstract: A housing for a magnetofluidic sensor where the sensor has a plurality of drive magnet assemblies, magnetic fluid and an inertial body. The housing has a plurality of ports for securing respective drive magnet assemblies, such that a portion of each drive magnet assembly is positioned within the housing proximate the magnetic fluid. Each drive magnet assembly includes a magnetic field source for creating a magnetic field within the magnetic fluid for acting upon the inertial body. Each drive magnet assembly also includes a sensing element for sensing movement of the inertial body within the magnetic fluid.

Abstract: A computer input device used to input coordinates and three-dimensional graphical information into a computer. The device includes an acceleration sensor that has a fixed volume vessel containing a magnetic fluid. A non-magnetic inertial body is located in the magnetic fluid. Three magnetic field source are located on three perpendicular axes where each magnetic field source has an output for connection to a computer.