Bimorph

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

Optical Microscanners and Microspectrometers using Thermal Bimorph Actuators

Abstract: Preface. 1. Introduction. 2. Basics for a thermally actuated micromirror. 3. Microscanner technology. 4. One-dimensional microscanner. 5. Two-dimensional microscanner. 6. Advanced Optical Filters of Porous Silicon. 7. Micromachining using porous Silicon. 8. Tunable Optical Filter and IR Gas Spectroscopy. 9. Conclusions and outlook. Appendices. A.1: Complement to the curvature calculation due to residual stress. A.2: Complement to the static temperature distribution calculation. A.3: Large deflections. References. Symbols and Abbreviations. Glossary of terms. Acknowledgments.

Soft-handling gripper driven by piezoceramic bimorph strips

Abstract: This paper is a study on the hybrid position/force control of a two-fingered miniature gripper driven by piezoelectric bimoph cells. The system is composed of the flexible cantilevers and a compact force sensor attached to the tip of one finger. Control action is applied by two piezoelectric bimorph strips placed at the base of each finger. The theoretical model of the electro-mechanical system is developed and applied to the study of a control problem where the gripper is commanded to grasp its object with a time-constant force 0.01 N at a prescribed commanded fingertip position. The PID control algorithm is introduced to drive the gripper.The system control behaviour is examined both theoretically and experimentally.

High stability bimorph scanning tunneling microscope

Abstract: A novel scanning tunneling microscope (STM) is described which is constructed almost entirely of one metal e.g. aluminum and uses bimorph piezoelectric disks as the x, y, z drive elements. The design uses a simple, rugged tirpod configuration for the fine motion drive arms. Coarse motion of the sample, which is mounted on an aluminum holder, is achieved by pushing, or pulling, with a piezoelectric louse. Differential thermal expansion effects are avoided by design, to first order, and the resulting drift is ≦0.5 Å per minute after only a short warm-up period. It is easy to build and operate, and has good immunity to mechanical vibrations.

Nano-electromechanical Drumhead Resonators from Two-Dimensional Material Bimorphs

Abstract: Atomic membranes of monolayer 2D materials represent the ultimate limit in the size of nano-electromechanical systems. However, new properties and new functionalities emerge by looking at the interface between layers in heterostructures of 2D materials. Here, we demonstrate the integration of 2D heterostructures as tunable nano-electromechanical systems, exploring the competition between the mechanics of the ultrathin membrane and the incommensurate van der Waals interface. We fabricate electrically contacted 5 or 6 μm circular drumheads of suspended heterostructure membranes of monolayer graphene on monolayer molybdenum disulfide (MoS2), which we call a 2D bimorph. We characterize the mechanical resonance through electrostatic actuation and laser interferometry detection. The 2D bimorphs have resonance frequencies of 5–20 MHz and quality factors of 50–700, comparable to resonators from monolayer or few-layer 2D materials. The frequencies and eigenmode shapes of the higher harmonics display split degenera...

A retrofitted energy harvester for low frequency vibrations

Abstract: Piezoelectric-based energy harvesting is an efficient way to convert ambient vibration energy into usable electric energy. However, its output power drops steeply with reducing excitation frequency. To improve the harvesting performance at low frequencies, a multi-impact harvester is proposed in this paper. The proposed design consists of a hung mass and two stiff piezoelectric cantilever beams. A series of impacts between the mass and cantilever beams are involved during the vibration of the mass, which triggers high frequency vibrations on the cantilever beams. Four equations of motion corresponding to different system statuses are presented to simulate the vibration of the harvester. Based on the linear piezoelectric theory, a distributed-parameter electromechanical model is used for the bimorph cantilever beam and its output power is calculated. For comparison, a conventional cantilever-beam-based harvester and a single-impact harvester are introduced and their output powers are also calculated. Under the same sinusoidal excitation, the modeling result shows that the power of the proposed harvester is more than three times larger than the ones from the conventional cantilever beam harvester and the single-impact harvester. The multi-impact harvester also occupies less space than the conventional one. A parametric study is presented in this paper for the multi-impact harvester considering different external resistances, hung masses, cantilever beam thicknesses and excitation frequencies.