Stress-based vapor sensing using resonant microbridges

D. R. Southworth, L. M. Bellan, Y. Linzon, H. G. Craighead, J. M. Parpia
2010 Applied Physics Letters  
We demonstrate that silicon-polymer composite microbridges provide a robust means of water vapor detection at ambient pressure. Volumetric changes in the reactive polymer alter the tension in a doubly clamped structure leading to large and rapid changes in the resonance frequency. We demonstrate stress-based sensing of water vapor in ambient pressure nitrogen using doubly clamped buckled beams coated with a hygroscopic polymer. We show stress sensitivity of around 20 kPa ͑ϳ170 ppb of water
more » ... ͒ and subsecond response time for coated microbridges.
doi:10.1063/1.3393999 fatcat:u5de7p65jfdejc7jxxeenly534