Abstract
Monolithically clamped bridge-on-diaphragm (BOD) structures for pressure sensor applications were fabricated by means of Nd: YAG-laser micromachining and anisotropic KOH-etching techniques. The pressure/frequency-dependence of the BOD structures was measured by acoustical resonance excitation and optical detection of the microbridge and applying an external pressure between-0.8 bar and+1 bar to the diaphragm. In this vacuum/atmospheric pressure range the pressure/frequency-characteristic is quite linear with a sensitivity of about 4.5 kHz/bar and a fundamental bridge resonance frequency of 82 kHz. Extensive finite-element modelling has been carried out to optimize the geometrical dimensions of the BOD structures with respect to maximum sensitivity and pressure range. Using the same BOD structure layout it is possible to realize pressure sensors with applications ranging from 0.5 to 12 bar by only varying the thickness of the diaphragm. Varying the BOD structure layout to smaller dimensions the pressure sensors can be operated up to 100 bar with sensitivities of about 141 Hz/bar.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Alavi, M.; Büttgenbach, S.; Schumacher, A.; Wagner, H.-J.: (1991) New microstructures in silicon using laser machining and anisotropic etching. Proc. Micro System Technologies'91, Berlin, Oct. 29-Nov. 1, pp. 322–324
Alavi, M.;Fabula T.;Schumacher, A.;Wagner, H.-J.: (1993) Monolithic microbridges in silicon using laser machining and anisotropic etching. Sensors and Actuators A, 37–38, pp. 661–665
Buser, R.A.;Schultheis, L.;de Rooij, N.F.: (1991) Silicon pressure sensor based on a resonating element. Sensors and Actuators A, 25–27, pp. 717–722
Fabula, T.;Wagner, H.-J.;Schmidt, B.;Büttgenbach, S.: (1994) Triple-beam resonant silicon force sensor based on piezoelectric thin films. Sensors and Actuators A, 41–42, pp. 375–380
Greenwood, J.C.;Satchell, D.W.: (1988) Miniature silicon resonant pressure sensor. IEE Proc., 135 (5), pp. 369–372
Ikeda, K.;Kuwayama, H.;Kobayashi, T.;Watanabe, T.;Nishikawa, T.;Yoshida, T.;Harada, K.: (1990) Silicon pressure sensor integrates resonant strain gauge on diaphragm. Sensors and Actuators, A21–A23, pp. 146–150
Prak, A.;Fabula, T.;Wagner, H.-J.;Elwenspoek, M.: (1994) Resonant microsensors. Techn. Digest of the UETP-MEMS Course, ed. FSRM, Neuchâtel, Switzerland
Schumacher, A.; Alavi, M.; Fabula, T.; Schmidt, B.; Wagner, H.-J.: (1994) Monolithic bridge-on-diaphragm microstructure for sensor applications. Proc. Micro System Technologies '94, Berlin, Germany, Oct. 19–21, pp. 309–316
Tilmans, H.A.C.;Elwenspoek, M.;Fluitman, J.H.J.: (1992) Micro resonant force gauges. Sensors and Actuators A, 30, pp. 35–53
Thornton, K.E.B.;Uttamchandani, D.;Culshaw, B.: (1990) A sensitive optically excited resonator pressure sensor. Sensors and Actuators A, 24, pp. 15–19
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wagner, H.J., Schumacher, A., Alavi, M. et al. Monolithic bridge-on-diaphragm structure for pressure sensor applications. Microsystem Technologies 1, 191–195 (1995). https://doi.org/10.1007/BF01371494
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01371494