Analog floating-gate inclinometer
AssigneeTexas Instruments Incorporated
InventorMark Eskew
Life of this patent
Estimating the term…
Abstract
An analog floating-gate (AFG) inclinometer where a plurality of AFG sensors are provided to detect the presence of a discharge caused by settling of a conductive liquid droplet contained in a sealed microchannel under gravity. A plurality of sensor port electrodes associated with the AFG sensors are placed along the length of a curved sealed microchannel of the inclinometer at specific positions calibrated to corresponding angular inclinations. Discharge detected at a specific AFG sensor port during measurement due to the movement of the conductive liquid droplet under gravity is used in determining a surface inclination being measured.
Claims20
An inclinometer, comprising:
- a semiconductor substrate;
- a dielectric layer over the semiconductor substrate, the dielectric layer defining a sealed arcuate microchannel containing a conductive liquid droplet;
- access port electrodes in the sealed arcuate microchannel, each of the access port electrodes associated with a reference electrode within a proximity of the respective access port electrode and disposed along a curvature of the sealed arcuate microchannel, the access port electrodes spaced from one another with an arc length that is calibrated to an angular inclination resolution;
- and
- analog floating-gate (AFG) devices in the semiconductor substrate, each corresponding to one or access port electrodes, wherein each of the AFG devices comprises a first conductor electrically coupled to the corresponding access port electrode and a second conductor electrically coupled to the reference electrode associated with the corresponding access port electrode.
A method of fabricating an analog floating-gate inclinometer, the method comprising:
- forming analog floating-gate (AFG) devices in a semiconductor substrate, wherein each of the AFG devices comprises a first conductor and a second conductor;
- defining an arcuate microchannel in a dielectric layer disposed over the semiconductor substrate, the arcuate microchannel including access port electrodes, each of the access port electrodes associated with a reference electrode formed within a proximity of the respective access port electrode and disposed along a curvature of the arcuate microchannel, the access port electrodes spaced from one another with an arc length that is calibrated to an angular inclination resolution;
- providing an electrical connection path coupling each access port electrode to the first conductor of a corresponding AFG device and an electrical connection path coupling the reference electrode associated with the access port electrode to the second conductor of the corresponding AFG device;
- injecting a conductive liquid droplet into the arcuate microchannel;
- and
- sealing the arcuate microchannel with a cap structure to form a sealed arcuate microchannel in the dielectric layer.
Dependencies are inferred from the claim text.