Design and performance of a microcantilever-based hydrogen sensor
2002; Elsevier BV; Volume: 88; Issue: 2 Linguagem: Inglês
10.1016/s0925-4005(02)00315-5
ISSN1873-3077
AutoresDavid R. Baselt, Bernd Frühberger, E.H. Klaassen, Sabina Cemalovic, C.L. Britton, Sanjay V. Patel, Todd Mlsna, D.L. McCorkle, Bruce Warmack,
Tópico(s)Advanced MEMS and NEMS Technologies
ResumoThis paper describes the design of, and the effects of basic environmental parameters on, a microelectromechanical (MEMS) hydrogen sensor. The sensor contains an array of 10 micromachined cantilever beams. Each cantilever is 500 μm wide×267 μm long×2 μm thick and has a capacitance readout capable of measuring cantilever deflection to within 1 nm. A 20-nm-thick coating of 90% palladium–10% nickel bends some of the cantilevers in the presence of hydrogen. The palladium–nickel coatings are deposited in ultra-high-vacuum (UHV) to ensure freedom from a “relaxation” artifact apparently caused by oxidation of the coatings. The sensor consumes 84 mW of power in continuous operation, and can detect hydrogen concentrations between 0.1 and 100% with a roughly linear response between 10 and 90% hydrogen. The response magnitude decreases with increasing temperature, humidity, and oxygen concentration, and the response time decreases with increasing temperature and hydrogen concentration. The 0–90% response time of an unheated cantilever to 1% hydrogen in air is about 90 s at 25 °C and 0% humidity.
Referência(s)