%0 Journal Article %J (IEEE) Transactions on Instrumentation and Measurement %D 2001 %T Micromechanical voltage reference using the pull-in of a beam %A Cretu, E %A Rocha, L A %A Wolffenbuttel, R F %K bifurcation capacitive sensors electrostatic actuators finite element analysis mechanical stability micromachining microsensors semiconductor device models transfer standards voltage measurement 200 micron 9.1 to 9.5 V DC voltage reference bifurcati %P 1504-1507 %U http://ieeexplore.ieee.org/search/srchabstract.jsp?arnumber=982935&isnumber=21177&punumber=19&k2dockey=982935 %V 50 %X The pull-in voltage of a single-side anchored freestanding beam, under lateral deflection, has been investigated for application as a DC voltage reference. Two sets of electrodes, along side the tip, are used for parallel-plate type of electrostatic actuation of the 200 ?m long beam in the plane of the wafer. Another set of buried electrodes is aligned with the plate electrode at the free-standing tip and is used as a differential capacitor for the simultaneous detection of the displacement, with the purpose to determine the stability border and thus the pull-in voltage. The single-end clamping ensures that the pull-in voltage is insensitive to technology-induced stresses. A 2D energy-based analytical model for the static pull-in is compared with measurements. Bifurcation diagrams are computed numerically, based on a local continuation method. Devices have been designed and fabricated in an epi-poly process. Measurements are in agreement with modeling and confirm a pull-in voltage in the 9.1-9.5 V range. Reproducibility is limited by hysteresis and charging of the dielectric layer in between the electrodes. The device can be operated in feedback or as a seesaw, by using the two sets of electrodes %Z E. Cretu, L.A. Rocha, and R.F. Wolffenbuttel [2001] - %8 Dec. %9 article