Contact Mode MEMS Position Sensors with Piezoresistive Detection.

Measuring of linear position with contact MEMS sensors is a promising option for achieving sub-nm resolution, as demanded by micro-/nanotechnology community [1] . The position of specific point of interest can be calculated by bending detection of cantilevers or more complex MEMS flexures via different techniques: optical, capacitive, piezoelectric, etc. Prototyping of strain sensing devices with sidewall piezoresistors has been preferred in the present study due to multiple advantages, like: very few restrictions in flexures design, very high signal sensitivity and linearity, temperature and noise stability and CMOS compatibility. Comprehensive results obtained at characterization of contact MEMS position sensors, comprising two rigid members, monolithic flexures with various layouts and electrically identical piezoresistors for strain detection, are presented. Design approach for setting the sensitivity in the range from 20 μV/μm.V to 2 mV/μm.V has been demonstrated. Recently achieved results report extremely high temperature immunity of the sensor signal. [ABSTRACT FROM AUTHOR]