Conference Paper

Design simulation and theoretical analysis of glucose sensing using Polysilicon-based CMOS micromachined Piezoresistive Microcantilever

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Abstract

This work has focused on the design simulation analysis of a Polysilicon-based CMOS micromachined Piezoresistive Microcantilever beam for glucose sensing application. In principle, adsorption of glucose on a functionalized surface of the microfabricated cantilever will cause a surface stress and consequently the cantilever bending. In this paper, the microcantilever beam is constructed and bending analysis is performed so that the beam tip deflection could be predicted. The device model was simulated using CoventorWareTM, a commercial finite element analysis (FEA) tool designed specifically for MEMS applications. The structural variationof the piezoresistors designs on cantilever beam is also considered to increase the sensitivity of the microcantilevers sensor since the forces involved is very small. Besides, the mechanic characteristics of the microcantilever beam such as displacement were observed based on transient response characteristics using analytical method and simulation method with Matlab Simulink. We observed that the best output response which have fastest response, low overshoot and low steady state error is when d=3.30 and k=3.

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... In "in-vivo biosensing", where small cells are usually experimented for analysing the whole organism, microcantilever are generally preferred for sensing. The lower level detection ability and simple structure make these cantilevers more applicable in many applications like TG detection [16], continuous glucose monitoring [15], lab on chip [7], RF frequency alteration [13] and many other. 2 Microcantilevers are the structure which is mainly hinged at one end and free at other end, hence can easily deform (or deflected) by the applied uniform analyte pressure. ...
... 2 Microcantilevers are the structure which is mainly hinged at one end and free at other end, hence can easily deform (or deflected) by the applied uniform analyte pressure. However, rectangular cantilever beam are used for TG and glucose detection [2,15,7], as a RF switch for switching [1,12,13], antigen-antibody reaction [3] and many chemical and biological species concentration measurement. But their constant geometry makes them less effective in lower mass detection. ...
... The slotted or fractal surface gives good analyte adhesion and improves the sensor sensitivity. Henceforth, these designs can be used in lower mass loading application like TG detection [2,16] or glucose detection [15] at much lower concentration of blood serum nearly 1 or 2pl or less. The FEM software Intellisuite is used for modelling, virtual fabrication and analysis. ...
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Surface geometry plays an important role in case of analyte sensing and RF switching using beams and electrodes. In general, rather than simply supported beam and diaphragm, microcantilever beams are widely preferred in BIO-MEMS and RF-MEMS for biosensing and RF switching, respectively. The lower level detection ability and simple structure make these cantilevers more applicable in many applications. The rectangular cantilever beams are most widely used in TG detection. but due to their constant or planner geometry and non-adhesion of analyte they are less sensitive in case of nano or pico level biosensing. This paper introduces the fractal surface geometry concept for increasing the deflection sensitivity corresponding to lower molecular or analyte loading. The rectangular and stepped cantilever beam structures along with fractal surface are simulated and analysed for TG molecular pressure 294.3 Pa. Both the rectangular and stepped microcantilever beams with fractal surface exhibit better free end or tip deflection (nearly 2×) as compare to the planner surface based beam. The proposed fractal concept also reduces the actuation voltage requirement for perfect switching.
... In bio- MEMS, molecular mass and concentration can be inspected by microcantilever based biosensor [3, 4]. MEMS sensors are also utilized for TG [5] and glucose [6] detection. Potentiometric and amperometric type biosensors are also used for sensing purposes [1] . ...
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High performance and sensitivity of a microcantilever beam is much demanded in biosensing and needs accurate measurement of tip deflection under very low range of analyte adhesion. Constant geometry based rectangular microcantilevers are not good enough for micro or pico level triglyceride (TG) and glucose detection. With the same surface area, length and thickness, the proposed variable width based stepped microcantilever beams exhibit nearly twice or thrice more tip deflection corresponding to the same TG and glucose molecular pressure. With the less pull-in voltage requirement, such proposed stepped microcantilever beam based switches can be utilized in RF reconfigurable antenna for altering its operating frequency and radiation properties. Several configurations of proposed microcantilevers have been studied and analyzed for finding the optimal design with better deflection sensitivity. This paper also encompasses the mathematical modeling of proposed single and double stepped microcantilever beam, which exhibits good agreement with the simulation. © 2015, The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.
... MEMS cantilevers for bio sensing, are adequate to convert biomolecular event into specific measurable quantity. The applications of bio MEMS microcantilevers are pH detection [5], bio-recognition activities analysis and mass detection [1], antigen-antibody reaction [9], triglyceride detection [4], monolayers molecules attogram detection [3], biomolecular analysis such as DNA [2], monomethylmercury detection [6], triaxial tactile measurement [7] and glucose sensing using poly-silicon-based CMOS [8]. The main advantage of microcantilever biosensing is multiagent detection with the help of microcantilever array. ...
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