Bimorph

About: Bimorph is a research topic. Over the lifetime, 3339 publications have been published within this topic receiving 51880 citations.

Bimorph adaptive optics: elements, technology, and design principles

Abstract: The present paper is concerned with existing deformable bimorph mirrors, their advantages and disadvantages; an effective technology of their construction is proposed providing a significant increase of the mirrors sensitivity as well as their controllable aperture. In accordance with the technology described industrial one-channel bimorph mirrors have been developed and investigated intended for use in laser optics and as well as a 3.3-meter bimorph mirror for optical telescope. Results of the investigation strongly confirm the effectiveness of the proposed technology for improvement of characteristics of controllable bimorph mirrors which represent a perfect instrument for `small' adaptive optics being of great importance for laser techniques and astronomic telescopes even today.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Vibration control of an HDD disk-spindle system utilizing piezoelectric bimorph shunt damping: I. Dynamic analysis and modeling of the shunted drive

Abstract: This work proposes a new piezoelectric shunt damping methodology to control the vibration of a computer hard disk drive (HDD) disk-spindle system. The first part of this work (part I) deals with dynamic modeling of the piezoelectric shunted drive, while the second part of this work (part II) covers experimental implementation of the proposed shunt circuits. In the modeling, a target vibration mode which significantly restricts the recording density increment of the drive is determined by analyzing the dynamic characteristics of the conventional drive. This is achieved by undertaking both modal testing and finite element (FE) analysis. In order to effectively suppress the unwanted vibration of the target mode, a piezoelectric bimorph is then designed and integrated to the drive by considering the mode shapes of the target vibration mode. The mechanical impedance of the shunted bimorph is derived from lamination theory and piezoelectric constitutive equations. In this derivation, the electromechanical coupling coefficient of the shunted drive is analytically incorporated with the mechanical impedance. Using the coupling coefficient, the shunt damping performance for the target vibration mode is predicted and evaluated by presenting the displacement transmissibility.

Near-resonance wide-range operating electromechanical motor

Abstract: The present invention combines bending mode mechanical (frm) and electrical (fre) resonances, whereby a relatively good efficiency can be achieved within a relatively broad frequency range (Δf3). An electrical resonance (fre) or mechanical resonance is designed to be situated in the same order of magnitude as another mechanical resonance (frm), but separated therefrom. Preferably, the separation (Δf2) is smaller than 2f1 / Q 1, where f1 is the resonance frequency for the resonance having lowest quality value, and Q1 is the corresponding quality value of the mechanical resonance. An electromechanical motor comprising a driving element and electrical resonance circuit according to the above ideas may comprise a double bimorph driving element having one single actuating point influencing a body to be moved. The double bimorph driving element is excited in bending vibrations perpendicular to a main displacement direction, whereby both tangential and perpendicular motions are created by bending mode vibrations.

Smart microgrippers for bioMEMS applications

Abstract: Grasping and manipulating small or micro-objects is critical for a wide range of essential biological applications, such as the assembly of small parts in microsurgery, nerve repair, and selective manipulation or separation of cells, microbes, localized cell probing, measurement etc Different microgripping and releasing mechanisms have been reviewed and discussed in this chapter Smart microgrippers or microcages based on the combination of highly compressively stressed diamond-like carbon (DLC) and electroplated Ni bimorph structures or SU8 polymer layer and shape memory thin films have been designed, simulated, fabricated, and characterized Theoretical, simulation, and experimental results revealed that the radius of curvature of the bimorph layer can be adjusted by varying the DLC film stress and thickness ratio of the DLC to metal or polymer layers The angular deflection of the bimorph structures can be adjusted by varying the finger length The radius of curvature of the microcage is in the range of 20–100 μm, suitable for capturing and confining micro-objects with similar sizes The operation of this type of device is based on either (1) a large difference in thermal expansion coefficients of the DLC and the metal or polymer layers or (2) the shape memory effect Electrical tests have shown that these microcages can be opened efficiently utilizing a power smaller than 20 mW and a frequency of 100 Hz