Authors: Min You, Ya Lan Zhao, Jian Li Li, Ying Ying Li

Abstract: The effect of dual adhesives to form multi-layer on the stress distributed in adhesively bonded single lap aluminum joint was investigated using elasto-plastic finite element method (FEM). The results from the numerical simulation showed that the values of the peak stress along the bondline are influenced evidently when there is a multi-layer formed by a middle layer with higher elastic modulus adhesive and two layers with lower elastic modulus adhesive.

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Authors: Saurav Verma, Vinod Jain

Abstract: Cantilever-based sensors have emerged as a promising label free detection technique, which have been used for high precision mass detection and biomolecular recognition. By surface functionalization, the cantilever can be modified specific to certain compounds detection. Molecules adsorbed to one side of the cantilever will deflect the cantilever due to changes in surface stress. Alternatively, minute mass changes can be detected by monitoring the resonant frequency change of the cantilever for high-precision mass detections. This work is dedicated to finite element (FE) 3Dstructural modeling of three layers micromechanical sensors in ANSYS 13.0 gives 3D model which are close to reality mathematical models. Material used in cantilever for different layers are silicon-dioxide, poly-silicon and nitride. The emphasis of the analysis is put on tile effects of the angle of inclination of the concentrated force upon the deformed shape, the load-deflection relationship stresses and strain for further analysis with a greater degree of accuracy. The model we made is three different model i.e. single layer microcantilevers, three layers microcantilever with same height and three layers with different height. In three layer the centre layer i.e. second layer, is piezoresistive layer that helps to calculate Characteristics i.e. deflection, deformation, stress and strain in the cantilever for the given applied force that can we used for future analysis for the detection of biomolecules in various biosensing application. Finally the comparison of all the three different model of cantilever according to their characteristics.

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Authors: S. Subhashini, A. Vimala Juliet

Abstract: Sensors had gained importance in all fields of science and technology and development of real time small devices with high sensitivity for in situ measurements at low cost has gained momentum. Micromachined cantilever provides a solution to this hunt. MEMS cantilever are the simplest of all the other mechanical structures and hence is considered for the ease of fabrication. Here a chemical CO_{2} sensor is considered with the metal oxide layer as receptor to adsorb the CO_{2} molecules leading to an increase in mass and microcantilever as the transducer part converting the change in mass to change in natural frequency. The sensitive SnO_{2} layer increases the mass and hence decreases the resonant frequency. The inherent natural frequency of the cantilever is altered by the sensitive coating on top of the beam and the residual stresses present on the structure. In this paper, we investigate the SiO_{2} cantilever with SnO_{2} deposited on the top surface. Initially the microcantilever is analytically modelled and then is fabricated and characterized experimentally. Finally the error % is analysed between the analytical model and experimental results.

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