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When the cantilever beam thickness is scaled down to micron, the dimension of material and the intrinsic length scale affect the mechanical behavior of the beam. The purpose of this paper is analyzing the bending of cantilever micro-beam and presenting an exact relation for the beam deflection using Chen-Wang gradient plasticity theory. To this end, the Euler-Bernoulli beam theory is utilized to model a micro-beam and three cases including elastic, rigid-plastic and elasto-plastic beams are considered. Clear relations for elastic and plastic strains are given. For all mentioned cases, the beam deflection is determined for different intrinsic lengths and the obtained results are compared with each other and the data obtained from experimental tests and some explanations are presented. The results obtained from classical theory are also shown in the results section to prove that classical theories don’t have the capability to predict behavior of micron-size structures precisely. Numerical results clarify the dependence of responses to the range of dimensions and intrinsic lengths. The comparison between present results and those observed from experimental tests authenticate the reliability of utilized gradient theory.

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We know, cantilevers are based for the most of the MEMS components, in this paper, the fabrication process of SiO2 micro cantilever array based on bulk micromachining technology is introduced. The results of which can be used to fabricate of SiO2 micro cantilever sensors. The micro-cantilever fabrication process is implemented in the 13th stage with two glass and talcous masks and it is also suspend by wet release technique. The main advantages of the proposed method can be expressed no need for advanced deposition equipment, design with minimum mask, fast and simplicity in implementation of the micro cantilever, avoid of complexity release from sacrificial layer, release the micro cantilever at environment temperature, low cost price and finally possible to implement in microelectronics research laboratories with limited equipment. The SiO2 micro cantilevers fabricate with 1and 2µm thickness, 50, 100, 150, 200, 250, 300, 350 and 400μm lengths, and 20 and 40µm widths. The resonant frequency and the spring constant values are also calculated for different materials (Si3N4, Si, Au, SiO2, Al and SU8) with various sizes. The SEM images results show that the lithographic process is correctly done on the roughness of the backside substrate, the fabrication process and Si etching operations controls are performed suitable, and micro-cantilevers are suspended with negligible stress.

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In this paper, the non-linear dynamic behavior of immersed AFM micro cantilever in liquid has been modeled. To increase the accuracy of the theoretical model, all necessary details for cantilever and sample surface have been taken into account. As for the theoretical model, the Timoshenko beam theory which takes the rotatory inertia and shear deformation effects into consideration has been adopted. For modeling the vibrational system, cantilever thickness, cantilever length and breadth, the angle between cantilever and sample surface, normal contact stiffness, lateral contact stiffness, tip height, breadth taper ratio, height taper ratio, time parameter and viscosity of the liquids have been considered. Differential quadrature method (DQM) has been used for solving the differential equations. During the investigation, the softening behavior was observed for all cases. Here, water, methanol, acetone and carbon tetrachloride has been supposed as immersion environments. Results show that increasing the liquid density reduces the resonant frequency. Time variable does not have any considerable effect on the non-linear resonant frequency. Theoretical modeling has been compared for a rectangular AFM cantilever with experimental works in both of the contact and non-contact modes in air and water environments. Results show good agreement.