Papers by Keyword: Cantilever

Abstract: Multilayer sheets or films have many potential applications in micro-nanoelectromechanical systems. When surface and scale effects are not considered, the bending of multilayer film systems can theoretically be discussed by the classical Stoney formula or Timoshenko formula. When the system has anisotropic surface stress or mismatch strain, the four-parameter bending model proposed by Narsu et al. can be used. However, if the thickness of the film is several nanometers and the bending radius of curvature is less than 1micron, the existing theoretical model is no longer applicable. For this reason, a bending formulation for the nanomulti-layer film system is derived and the structure of the multilayer film is optimized in this paper.

Abstract: In this paper we have developed a simple and inexpensive method to fabricate cilia-like silicone rubber-ferrofluid composite cantilever beams. The technique described can generate highly reproducible arrays of these microcantilevers ranging from 1 mm to 0.4 mm in diameter. We use a laser cutter to create moulds for the cantilevers making it a low cost and reliable process. The iron particles from the ferrofluid can uniformly dispersed, randomly arranged or isolated on the tip of the cantilever. Cantilevers with 400 μm diameter and up to 10 mm length are tested with low magnetic field of 15mT. We obtained maximum deflection of 82.5^o at 44 mT magnetic field.

Abstract: This paper presents modelling of various gas application to modified atomic force microscope sensor in order to change its existing dynamic characteristics. This paper represents part of continuous research, which is focused on improvement of scanning speed of atomic force microscope (AFM) sensor. Subject of our research is enhancement of dynamic characteristics of Atomic force microscope sensor. Natural frequency of AFM sensor is the main factor influencing max scanning speed of atomic force microscope. In case of working range of frequencies approaches to the resonant frequency of cantilever, scanning results becoming inaccurate and unreliable. Improvement of properties of atomic force sensor made by adding additional nonlinear aerodynamic force to the AFM sensor. This force would act as additional controllable stiffness element, which allows shift resonant frequency to higher side. In this paper is presented research of additional nonlinear force behavior using different gasses as well as compressed air. Research covers factor of humidity of compressed air. Our research performed using 3D atomic microscope cantilever model in SolidWorks flow simulation software. Results of simulation delivered as dependencies of additional stiffness in the AFM sensor in all modelled cases. Finally, results presented in graphical form and conclusions are drawn.

Abstract: This paper dedicated of introduction of dynamic model of improved mechanical system of sensor of atomic force microscope. The subject of the research is enhancement of dynamic characteristics of cantilever - main mechanical part of sensor. These characteristics defines frequency of oscillations of mentioned cantilever and are main limitations of the speed of scanning procedure of the microscope. Modification of original dynamic system of atomic force microscope made adding nonlinear additional stiffness, created by stream of compressed air. In order to determine dynamic characteristics of modified system there are necessary to create corresponding dynamic model. Parameters of such model were defined using experimental research and theoretically from 3-D model of microscope cantilever. Solution of this model brings dependencies between air gap, pressure of compressed air and oscillation frequency of cantilever. Finally, results there are presented and conclusions are drawn.

Abstract: The ability to self-energize wireless sensor node promote the popularity of energy harvesting technique especially by using ambient vibration as the source of energy. In addition, the successful integration of the energy harvesting element on the same wafer as a wireless sensor node will promote the production in the MEMS scale and will reduce the overall cost of production. The usage of the cantilever structure as the transducer for converting mechanical energy (vibration) due to deflection of cantilever into the electrical energy is possible by depositing piezoelectric material on the cantilever. The usage of cantilever provide the simplest way for fabrication in the MEMS scale and also provide the ability to achieve low natural frequency. This paper present the work done on the simulation of the cantilever structure with the top end and back etch proof mass towards achieving low natural frequency in the MEMS scale by using IntelliSuite software.

Abstract: Atomic force microscope (AFM) is widely used to measure nanoforce in the analysis of nanomechanical and biomechanical properties. As the critical factor in the nanoforce measurement, the stiffness of the AFM cantilever must be determined properly. In this paper, an accurate and SI-traceable calibration method is presented to obtain the stiffness of the AFM cantilever in the normal direction. The calibration system consists of a homemade AFM head and an ultra-precision electromagnetic balance. The calibration is based on the Hooke's law i.e. the stiffness is equal to the force divided by the deflection of the cantilever. With this system, three kinds of cantilevers were calibrated. The relative standard deviation is better than 1%. The results of these experiments showed good accuracy and repeatability.

Abstract: This paper presents results of the formation of high aspect nanostructures by local deposition of carbon, stimulated by focused ion beam (FIB). The structures used in the modification of the probe sensors were cantilevers for atomic force microscopy (AFM). The FIB structure of 5 mm length and 50 mm radius of curvature formed on the surface of the cantilever tip has shown to improve the accuracy of measurement by AFM. The outcome of this study is useful for the development of manufacturing processes and modification of the probe sensor-cantilever AFM structures of field-electron emitters as well as in the studies of micro- and nanosystems technology.

Abstract: The vibration of barrel has considerable influence on accuracy when firing, for obtaining the disciplinarian of barrel vibration, barrel is considered as a cantilever in this paper, on that base, its transverse vibration equation has been established, and forced response can be figured out by using modal analysis method. The vibration characteristics of barrel were numerically simulated for different charge weight, besides, two situations that the barrel with or without gas pressure have been compared. In solving process, the displacement、velocity and acceleration of projectile are real dates. The simulation results indicate that static offset has a great influence on vibration characteristics, with the increasing of the projectile′s initializing speed, the amplitude of the barrel′s vibration is lower without static offset, and the effect of gas pressure can decrease the amplitude of vibration considerably.

Abstract: In this paper, a simple microcantilever release process using anisotropic wet etching is presented. The microcantilever release is conducted at the final stage of the fabrication of piezoresistive microcantilever sensor. Issues related to microcantilever release such as microscopic roughness and macroscopic roughness has been resolved using simple technique. By utilizing silicon oxide (SiO₂) as the etch stop for the wet etching process, issues related to microscopic roughness can be eliminated. On the other hand, proper etching procedure with constant stirring of the etchant solution of KOH anisotropic etching significantly reduces the notching effect contributed by the macroscopic roughness. Upon the completion of microcantilever release, suspended microcantilever of 2μm thick is realized with the removal of SiO₂ layer using Buffered Oxide Etching (BOE).

Abstract: In order to reduce consumption of thermal flow meter and prolong its working life, this article makes a research on cantilever switch, which control the circuit and save its energy. A cantilever was added into flow meter and was put into the air flow aisle in front of sensors. Process was designed and nanoimprint method was used to realize cantilever. The device was simulated and the effect on reducing consumption was certified, which has great significance on thermal flow meter.