Sensor having improved selectivity
US6864692B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 2002 |
| Grant date | Mar 8, 2005 |
| Priority date | — |
| Expiry date | Dec 22, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/227
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sensor for determining the presence of an analyte is disclosed comprising a reactive layer disposed between a base plate and a movable plate. The reactive layer is configured to interact with an analyte effecting a change in capacitance between the base plate and movable plate. When the analyte has a polarity or overall Hildebrand solubility parameter that is similar to the reactive layer, the change in capacitance is caused by a swelling of the reactive layer as analyte is absorbed into the reactive layer. This results in a decrease in capacitance. When the analyte has a solubility parameter not near the reactive layer, the absorbed analyte causes the reactive layer's total polarity to increase, an effect that dominates swelling. This causes an increase in capacitance. A capacitive sensing circuit is included for measuring the change in capacitance which is indicative of the analyte exposed to the sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.