High sensitivity passive wireless strain sensor
US8104358B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 23, 2007 |
| Grant date | Jan 31, 2012 |
| Priority date | — |
| Expiry date | Jul 26, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0072
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A high sensitivity strain sensor that utilizes a micro-scale cavity built in a multi-layer structure, with a pair of interdigitalized capacitor incorporated on one of the layers, is described in this document. The device's capacitance changes produced by unattended deformations of the cavity can be used to measure the associated strain without using any movable electrodes. The sensor can be remotely energized from a radio frequency wave sent by a reader antenna to construct a battery-free wireless instrument. Changes on the sensor's resonant frequency are remotely detected so that a strain level is measured from fluctuations in the received signal. This detection method provides a simple, reliable and sensitive technique to measure small strain changes down to the pico-scale. Materials with a highly strain-dependant permittivity are integrated in the sensor to enhance its sensitivity. The proposed sensor consists of a simple planar structure. It can be used as the main component on low-cost, accurate and highly stable strain measuring instruments capable of monitoring very small strain levels. Furthermore, the sensor is passive, may be operated wirelessly, and can, thus, be used fo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.