Bimorph

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

An electromechanical x-ray optical element based on a hysteresis-free monolithic bimorph crystal

Abstract: A hysteresis-free electrically controlled X-ray optical element based on a monolithic bi-domain bimorphic piezoelectric actuator that is made of lithium niobate crystal was proposed and successfully tested in practice. This element is used for electronically controlled adjustment of the angular position of an X-ray optical monochromator in a range of up to 200″ and is characterized by a high relative linearity (up to 98%), repeatability (the repeatability error is no more than 2%), and low control voltages (up to 100 V). The hysteresis- free behavior of the dependence of the angular position of the element on the control element, which demonstrates the high efficiency of the hysteresis-free monolithic bimorphic piezoactuators as controlled elements of X-ray optics, is shown.

A passively tunable mechanism for a dual bimorph energy harvester with variable tip stiffness and axial load

Abstract: This paper presents a novel vibration-based piezoelectric energy harvester capable of passively tuning its resonant frequency to a wide range of frequencies. The device comprises a dual bimorph with a mass at its free end. A novel sliding mechanism, consisting of two oblique springs connected to the tip mass, is proposed to widen the resonance frequency of the device even to very low frequencies. The application of two oblique springs results in an additional stiffness and axial load that are introduced within the system, such that the resonance frequency of the device is now a function of both the stiffness and axial load associated with the spring forces. An operator can manually change the resonance frequency of the harvester just by small adjustments of the sliding mechanism. Further, the device allows one to tune the resonance frequency of the beam to match very low frequencies without the requirement of having a large proof mass. The analytical solution of an axially loaded cantilevered piezoelectric energy harvester with tip stiffness, using Euler–Bernoulli beam assumptions, is presented. A parametric case study is presented to demonstrate the performance of the device.

A Novel Adaptive Bimorph Focusing Mirror and Wavefront Corrector with Sub-Nanometre Dynamical Figure Control

Abstract: We present the design, fabrication and characterization of a novel adaptive X-ray optic by bringing together bimorph adaptive technology and the novel Elastic Emission Machining "super-polishing" technique. This super-polished adaptive mirror provides variable focal distance and local figure control in the sub-nm range. The optic has the potential to generate distortion-free beams, and enable wavefront control.

Dual-Structured Flexible Piezoelectric Film Energy Harvesters for Effectively Integrated Performance.

Abstract: Improvement of energy harvesting performance from flexible thin film-based energy harvesters is essential to accomplish future self-powered electronics and sensor systems. In particular, the integration of harvesting signals should be established as a single device configuration without complicated device connections or expensive methodologies. In this research, we study the dual-film structures of the flexible PZT film energy harvester experimentally and theoretically to propose an effective principle for integrating energy harvesting signals. Laser lift-off (LLO) processes are used for fabrication because this is known as the most efficient technology for flexible high-performance energy harvesters. We develop two different device structures using the multistep LLO: a stacked structure and a double-faced (bimorph) structure. Although both structures are well demonstrated without serious material degradation, the stacked structure is not efficient for energy harvesting due to the ineffectively applied strain to the piezoelectric film in bending. This phenomenon stems from differences in position of mechanical neutral planes, which is investigated by finite element analysis and calculation. Finally, effectively integrated performance is achieved by a bimorph dual-film-structured flexible energy harvester. Our study will foster the development of various structures in flexible energy harvesters towards self-powered sensor applications with high efficiency.

Electrical system for electrostrictive bimorph actuator

Abstract: A bimorph actuator is driven by electrostrictive materials configured to change length in response to applied electrical field. A first electrostrictive material is positioned between a first electrode and a second electrode. A second electrostrictive material is positioned between a second electrode and a third electrode. The second electrostrictive material and the first electrostrictive material are attached to each other such that a differential change in their respective lengths results in a lateral motion. A first voltage source provides a voltage differential between the first electrode and the third electrode. A second variable voltage applied to the second electrode causes the length of the first electrostrictive material to lengthen when the second electrostrictive material shortens, and vice versa. A system of electrodes for the bimorph actuator and a method for actuating electrostrictive materials are also provided.