High sensitivity integrated micromechanical electrostatic potential sensor
US5517123A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1994 |
| Grant date | May 14, 1996 |
| Priority date | — |
| Expiry date | Aug 26, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R29/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention is a method and apparatus for electrostatic potential sensing by using electromechanical microstructures. The mechanical microstructure may be fabricated by either surface micromachining or bulk-micromachining. The sensor comprises a movable plate which is movable in the lateral dimension and which is suspended from and above a substrate bearing an isolated electrically conductive layer. The layer acts as the sensor electrode and is brought in contact with or near the object the electrostatic potential of which is to be sensed. The movable plate is suspended between two fixed, suspended and cantilevered plates. The three suspended plates collectively form two capacitors with the two fixed plates comprising the first plate of first and second capacitors and the movable plate comprising the second plate of both capacitors. A potential differential between the movable plate and the conductive layer causes lateral movement of the movable plate, resulting in a change in the capacitance of the two capacitors. Resolving circuitry converts the change in capacitance into an output signal indicative of the electrostatic difference between the movable plate and the conductive la…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.