Chemical sensor and coating for same
US6237397A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1999 |
| Grant date | May 29, 2001 |
| Priority date | — |
| Expiry date | Oct 6, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/0427
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An acoustic wave based-chemical sensor containing a crystal substrate and a coating of small particulate matter is disclosed. The small particulate matter can be graphite particles. Transducers are connected to the crystal substrate to generate an alternating potential across the crystal substrate, which in turn causes the crystal to resonate due to the converse piezoelectric effect. The coating absorbs the analyte, thus changing the mass of the sensor, and accordingly changing its resonant frequency. The transducers detect this change in resonant frequency to indicate that the analyte is present. The use of small particulate matter results in a coating having a large surface area which facilitates mass uptake of large amounts of VOCs, improved acoustic properties even with relatively thick coatings, and a high operational temperature range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.