Title :
Displacement Sensing With Silicon Flexures in MEMS Nanopositioners
Author :
Bazaei, Ali ; Maroufi, Mohammad ; Mohammadi, Arash ; Moheimani, S.O.R.
Author_Institution :
Sch. of Electr. Eng. & Comput. Sci., Univ. of Newcastle, Newcastle, NSW, Australia
Abstract :
We report a novel piezoresistive microelectromechanical system (MEMS) differential displacement sensing technique with a minimal footprint realized through a standard MEMS fabrication process, whereby no additional doping is required to build the piezoresistors. The design is based on configuring a pair of suspension beams attached to a movable stage so that they experience opposite axial forces when the stage moves. The resulting difference between the beam resistances is transduced into a sensor output voltage using a halfbridge readout circuit and differential amplifier. Compared with a single piezoresistive flexure sensor, the design approximately achieves 2, 22, and 200 times improvement in sensitivity, linearity, and resolution, respectively, with 1.5-nm resolution over a large travel range exceeding 12 μm.
Keywords :
differential amplifiers; displacement measurement; microfabrication; microsensors; nanopositioning; piezoresistive devices; readout electronics; resistors; silicon-on-insulator; MEMS fabrication process; MEMS nanopositioners; beam resistances; differential amplifier; half-bridge readout circuit; microelectromechanical system; piezoresistive MEMS differential displacement sensing; piezoresistive flexure sensor; piezoresistors; sensor output voltage; silicon flexures; Bridge circuits; Micromechanical devices; Nanopositioning; Piezoresistance; Piezoresistive devices; Sensors; Suspensions; Displacement sensor; SOI-MEMS; nanopositioning; piezoresistivity; piezoresistivity.;
Journal_Title :
Microelectromechanical Systems, Journal of
DOI :
10.1109/JMEMS.2014.2316325
