Detection of volatile organic compounds (VOCs) with polymer-coated cantilevers

Abstract Changes in the resonance frequency of polymer-coated cantilevers due to gas absorption is shown to be a promising detection mechanism for gases. We prepared SiNx cantilevers based on micromachined Si wafers and used polydimethylsiloxane (PDMS) as polymeric prototype coating. We measured the resonance frequency response of cantilevers end-coated with polymer on exposure to different vapor concentrations of n-octane, toluene, and n-butanole and determined high sensitivities with respect to cantilevers without polymer coating. By using the first higher resonance mode, we found with our configuration sensitivities up to −0.0988 Hz/ppm for small concentrations of n-octane. It is demonstrated here how the sensitivity of the chemical sensor can be improved by varying the deposited polymer mass.

[1]  Panos G. Datskos,et al.  Uncooled thermal imaging using a piezoresistive microcantilever , 1996 .

[2]  Thomas Thundat,et al.  Vapor detection using resonating microcantilevers , 1995 .

[3]  Peter Vettiger,et al.  Sequential position readout from arrays of micromechanical cantilever sensors , 1998 .

[4]  James K. Gimzewski,et al.  A femtojoule calorimeter using micromechanical sensors , 1994 .

[5]  Thomas Thundat,et al.  Thermal and ambient-induced deflections of scanning force microscope cantilevers , 1994 .

[6]  Henry Baltes,et al.  IC microtransducers: new components with old materials? , 1997, Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components.

[7]  A. Hierlemann,et al.  Chiral discrimination of inhalation anesthetics and methyl propionates by thickness shear mode resonators: new insights into the mechanisms of enantioselectivity by cyclodextrins. , 1997, Analytical chemistry.

[8]  Thomas Thundat,et al.  Micromechanical radiation dosimeter , 1995 .

[9]  Arun Majumdar,et al.  Photothermal measurements at picowatt resolution using uncooled micro-optomechanical sensors , 1997 .

[10]  Henry Baltes,et al.  The CMOS MEMS nose-fact or fiction? , 1997, ISIE '97 Proceeding of the IEEE International Symposium on Industrial Electronics.

[11]  W. Göpel.  Sensoren und Physikalische Chemie , 1993 .

[12]  Panos G. Datskos,et al.  Remote infrared radiation detection using piezoresistive microcantilevers , 1996 .

[13]  P. Hansma,et al.  A nondestructive method for determining the spring constant of cantilevers for scanning force microscopy , 1993 .

[14]  W. Göpel,et al.  Chemical sensors based upon polysiloxanes: comparison between optical, quartz microbalance, calorimetric, and capacitance sensors , 1993 .

[15]  Wolfgang Göpel,et al.  Supramolecular and polymeric structures for gas sensors , 1995 .

[16]  James K. Gimzewski,et al.  Observation of a chemical reaction using a micromechanical sensor , 1994 .

[17]  James K. Gimzewski,et al.  Thermal analysis using a micromechanical calorimeter , 1996 .

[18]  Panos G. Datskos,et al.  Remote optical detection using microcantilevers , 1996 .

[19]  Thomas Thundat,et al.  Adsorption-induced surface stress and its effects on resonance frequency of microcantilevers , 1995 .

[20]  E. A. Wachter,et al.  Detection of mercury vapor using resonating microcantilevers , 1995 .

[21]  Thomas Thundat,et al.  Viscous drag measurements utilizing microfabricated cantilevers , 1996 .