A MEMS based blood glucose measurement sensor using twin-cantilever structure

Abstract

This paper aims to propose a blood glucose measurement sensor using a MEMS-based twin cantilever structure, which is highly reliable and accurate. Two identical microcantilever beams featuring a dimension of 500μm x 100μm x 10μm, were designed and fabricated using the IntelliFab module of the IntelliSuite MEMS software. One was deposited with a piezoelectric material Lead Zirconate Titanate (PZT), which converts mechanical stress into a change in electric potential, and the other, with doped polysilicon (a piezoresistor), which translates mechanical energy in terms of a change in resistance. Glucose detection in the blood sample was achieved by coating the top surface of a cantilever beam with glucose-sensitive polymer PAA-ran-3-PAAPBA. Mechanical bending of the cantilever beam was observed due to the presence of glucose in blood sample and the output voltage proportional to glucose concentration has been measured using op-Amp as a readout circuitry. The resulting output voltage corresponding to a glucose concentration of 162mg/dL is found to be 47.49mV.