Abstract
Micro electro mechanical systems (MEMS) frequently require displacement measurements with high accuracy, a high sampling rate, and a long sensing travel. However, the available methods for measuring displacements of micro devices are typically limited in terms of at least one of these figures of merit. In this paper, we present a novel implementation of an optical encoding method for measuring displacements of micro devices that provides good capabilities in all of these figures of merit. The optical encoding system combines a commercial reading apparatus with a custom-made metal grating that can be easily produced during MEMS fabrication. Experimental tests demonstrate the ability of the system to measure displacements with a resolution of 25 nm and sampling rate of 1 MHz, under a variety of displacement rate functions.
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References
O’Shea SJ, Ng CK, Tan YY, Xu Y, Tay EH, Chua BL, Tien NC, Tang XS, Chen WT (2001) Force based displacement measurement in micromechanical devices. Applied Physics Letters 825:4031–4033. doi:10.1063/1.1380398.
Emery RD, Povirk GL (2003) Tensile behavior of free-standing gold films. Part I. Coarse-grained films. Acta Materialia 51:2067–2078. doi:10.1016/S1359-6454(03)00006-5.
Sharpe WN, Bin Yuan Vaidyanathan R Jr., Edwards RL (1997) Measurements of Young's modulus, Poisson's ratio, and tensile strength of polysilicon. IEEE 424–429
Lee CW, Zhang XM, Tjin SC, Liu AQ (2004) Nano-Scale displacement measurement of MEMS device using fiber optic interferometry. Journal of the Institution of Engineers 445:1–8.
Zhang XJ, Zappe S, Bernstein RW, Sahin O, Chena CC, Fish M, Scott MP, Solgaard O (2004) Micromachined silicon force sensor based on diffractive optical encoders for characterization of microinjection. Sensors and Actuators 114:197–203. doi:10.1016/j.sna.2003.11.028.
Fourment S, Arguel P, Noullet JL, Lozes F, Bonnefont S, Sarrabayrouse G, Jourlin Y, Jay J, Parriaux O (2004) A silicon integrated opto-electro-mechanical displacement sensor. Sensors and Actuators 110:294–300. doi:10.1016/j.sna.2003.10.067.
Alciatore DG, Histand MB (1999) Introduction to mechatronics and measurement systems. McGraw-Hill, NY
Cloud G (1995) Optical methods of engineering analysis. Published Cambridge, University Press
Ohring M (1992) The Materials Science of Thin Films. Academic, Boston.
Brantley WA (1973) Calculated elastic constants for stress problems associated with semiconductor devices. Journal of Applied Physics 44:534–535. doi:10.1063/1.1661935.
Rapp D Thermo-optical properties of silicon. Available from: www.gps.caltech.edu/genesis/Thermal-Coll.html
Bartl J, Baranek M (2004) Emissivity of aluminium and its importance for radiometric measurement. Measurement of Physical Quantities 43:31–36.
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Ben-David, E., Kanner, O. & Shilo, D. A New Method for Measuring Displacements of Micro Devices by an Optical Encoding System. Exp Mech 49, 823–827 (2009). https://doi.org/10.1007/s11340-008-9218-1
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DOI: https://doi.org/10.1007/s11340-008-9218-1