Enabling Improved Performance from MEMS Chemical Microsensors

 

Phillip H. Rogers, Steve Semancik

 

The work to be discussed involves efforts in three areas that were motivated by the desire to enhance the measurement capabilities of MEMS-based chemical microsensors.  Devices fabricated using a NIST design and wafer runs at MIT-Lincoln Labs have been utilized in studies to improve sensor stability and the repeatability of analyte recognition.  A temperature feedback routine developed for more reliable temperature programmed operation has been shown to improve discrimination and recognition of test analytes.  Further improvements in performance and in the understanding of transduction pathways have been achieved through a new method for processing raw temperature programmed sensing signal. Additionally, improvements in microsensor design have been made in the way of designing, modeling and fabrication of single-layer silicon nitride membrane deposited Pt heater and Pt electrode microsensor chemical sensing elements. These devices are predicted to have improved temperature uniformity across the sensing film and minimal optical interferences from contaminants that can be left behind due to multi-layer fabrication.