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Chemical vapor detection using a capacitive micromachined ultrasonic transducer.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Lee, Hyunjoo Jenny Park, Kwan Kyu Kupnik, Mario Oralkan, Omer Khuri-Yakub, Butrus T. |
| Copyright Year | 2011 |
| Abstract | Distributed sensing of gas-phase chemicals using highly sensitive and inexpensive sensors is of great interest for many defense and consumer applications. In this paper we present ppb-level detection of dimethyl methylphosphonate (DMMP), a common simulant for sarin gas, with a ppt-level resolution using an improved capacitive micromachined ultrasonic transducer (CMUT) as a resonant chemical sensor. The improved CMUT operates at a higher resonant frequency of 47.7 MHz and offers an improved mass sensitivity of 48.8 zg/Hz/μm(2) by a factor of 2.7 compared to the previous CMUT sensors developed. A low-noise oscillator using the CMUT resonant sensor as the frequency-selective device was developed for real-time sensing, which exhibits an Allan deviation of 1.65 Hz (3σ) in the presence of a gas flow; this translates into a mass resolution of 80.5 zg/μm(2). The CMUT resonant sensor is functionalized with a 50-nm thick DKAP polymer developed at Sandia National Laboratory for dimethyl methylphosphonate (DMMP) detection. To demonstrate ppb-level detection of the improved chemical sensor system, the sensor performance was tested at a certified lab (MIT Lincoln Laboratory), which is equipped with an experimental chemical setup that reliably and accurately delivers a wide range of low concentrations down to 10 ppb. We report a high volume sensitivity of 34.5 ± 0.79 pptv/Hz to DMMP and a good selectivity of the polymer to DMMP with respect to dodecane and 1-octanol. |
| File Format | PDF HTM / HTML |
| DOI | 10.1021/ac201626b |
| PubMed reference number | 22124375 |
| Journal | Medline |
| Volume Number | 83 |
| Issue Number | 24 |
| Alternate Webpage(s) | http://stanford.edu/group/khuri-yakub/publications/11_HJLee_01.pdf |
| Alternate Webpage(s) | http://www-kyg.stanford.edu/khuriyakub/opencms/Downloads/11_HJLee_01.pdf |
| Alternate Webpage(s) | https://doi.org/10.1021/ac201626b |
| Journal | Analytical chemistry |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
