Abstract
The use of chemically selective thin-film coatings has been shown to enhance both the chemical selectivity and sensitivity of microcantilever (MC) chemical sensors. As an analyte absorbs into the coating, the coating can swell or contract causing an in-plane stress at the associated MC surface. However, much of the stress upon absorption of an analyte may be lost through slippage of the chemical coatings on the MC surface, or through relaxation of the coating in a manner that minimizes stress to the cantilever. Structural modification of MC chemical sensors can improve the stress transduction between the chemical coating and the MC. Surfaces of silicon MC were modified with focused ion beam milling. Sub-micron channels were milled across the width of the MC. Responses of the nanostructured, coated MCs to 2,3-dihydroxynaphthalene and a series of volatile organic compounds (VOCs) were compared to smooth, coated MCs. The analytical figures of merit for the nanostructured, coated MCs in the sensing of VOCs were found to be better than the unstructured MCs. A comparison is made with a previously reported method of creating disordered nanostructured MC surfaces.
Original language | English |
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Pages (from-to) | 417-424 |
Number of pages | 8 |
Journal | Ultramicroscopy |
Volume | 97 |
Issue number | 1-4 |
DOIs | |
State | Published - 2003 |
Funding
This research was supported by the US Department of Energy, Environmental Management Program under Grant DOE DE-FG07-98ER62718 and by DOE Basic Energy Sciences under Grant DE-FG02-96ER14609. Oak Ridge National Laboratory is operated for the US Department of Energy by UT-Battelle under Contract DE-AC05-96OR22464.
Keywords
- Chemical sensors
- Microcantilevers
- Selective coatings
- Surface modification