many shape and topology optimization methods have been inspired from the nature. in this paper, two different optimization algorithms based on the adaptive biological growth (abg) have been applied to some structural elements. the first algorithm is developed for the shape optimization and is applied to a plate with a central hole as well as a fillet plate. the second algorithm is the soft kill...

We developed a dual-probe (DP) atomic force microscopy (AFM) system that has two independently controlled probes. The deflection of each cantilever is measured by the optical beam deflection (OBD) method. In order to keep a large space over the two probes for an objective lens with a large numerical aperture, we employed the OBD sensors with obliquely incident laser beams. In this paper, we des...

In order to reduce the vibration of smart structures, this paper gets the optimal location of piezoelectric patch by the D-optimal design principle, and then uses the fuzzy logic to control the smart structures vibration. The fuzzy IF-THEN rules are established on analysis of the motion traits of cantilever beam. The fuzzy logic controller (FLC) designs base on using the displacement and veloci...

Detailed measurements of the frequency responses of a series of rectangular atomic force microscope ~AFM! cantilever beams, immersed in a range of fluids, have been performed to test the validity and accuracy of the recent theoretical model of Sader @J. Appl. Phys. 84, 64 ~1998!#. This theoretical model gives the frequency response of a cantilever beam, that is immersed in a viscous fluid and e...

The detection of higher modes of oscillation in atomic force microscopy can provide additional information on sample properties. However, the limited bandwidth of the photodiode in the beam deflection detection technique often limits the detectable frequency range. We present a novel cantilever design, which allows lowering the frequency of higher modes of oscillation, maintaining the frequency...

The analysis of cantilever beams of small dimensions taking into the effect of fringing fields is studied and the parameters are estimated. Extracting the mechanical properties of MEMS devices has always been a challenge in terms of test time and test cost due to difficulties associated with accurate characterization of thin films. A technique for diagnosing the mechanical parameters of a canti...

We present a systematic investigation of the dynamic properties of silicon nitride cantilevers in air. The thermal noise spectra of cantilevers have been measured using a home-made optical deflection setup. Torsional and flexural resonances up to the seventh mode are observed. The dependence of resonance frequencies on the dimensions and mode number is studied in detail. It is found that underc...

Empirical estimates of the fundamental frequency of tall buildings vary inversely with their height, a dependency not exhibited by the various familiar models of beam behavior. This paper examines and explains this apparent discrepancy by analyzing the consequences of using two models to estimate such natural frequencies: A two-beam model that couples the bending of a classical cantilever to th...

Selective Ga + ion implantation and miring by focused ion beam exposure and subsequent wet chemical etching is used to fabricate micro/nanomechanical elements in Si. Freestanding elements with a ~ 30 nm membrane thickness are made by controlled selective underetching between unexposed and exposed areas. Ultrahigh-frequency cantilever beams have been made with resonances in the tens of MHz range...

We measure the adhesion energy of gold using a micromachined cantilever beam. Stress and stiffness of the beam are characterized by measuring the spectrum of mechanical vibrations and the deflection due to external force. We induce stiction between the beam and a nearby surface, employing capillary forces to determine the adhesion energy g . The obtained value g50.06 J/m is a factor of 6 smalle...