Bimorph

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

A 1×20 MEMS mirror array with large scan angle and low driving voltage for optical wavelength-selective switches

Abstract: Wavelength-selective switches (WSSs) are the core devices for reconfigurable optical add-drop multiplexers (ROADMs) that are essential in all-optical networks. WSSs based on microelectromechanical (MEMS) mirror arrays exhibit high potential due to their high switching speed and large port counts, but there still exist challenges to achieve large optical scanning angle at low voltage. This paper presents a 1×20 MEMS mirror array (MMA) design that can scan over 10° in both axes at less than 5 V. The MMA is based on an unique electrothermal bimorph actuator design that can perform 2D scanning and its fill factor reaches 96 %. The 1×20 MMA design has been successfully fabricated using a combined bulk- and surface- micromachining process. The size of each mirror plate is 240 μm by 500 μm. The measured maximum optical scan angles in the x-axis and y-axis are 29.3° and 11.8°, respectively, at 3 V. The measured response time is about 3.7 ms. The thermal crosstalks between adjacent electrothermal actuators are about 10 %. Long-term stability tests show that the angular drifts of the individual mirrors are about 0.002°/h.

A flat piezoelectric polymer film loudspeaker as a multi-resonance system

Abstract: A flat diaphragm full-range loudspeaker utilizing a piezoelectric polymer is described. This loudspeaker is characterized by an excellently simple constitution and multiresonance response characteristics. Since the fundamental resonant frequency of a loudspeaker should be as low as possible, it is convenient to utilize the flexural vibration of a bimorph diaphragm. The input-output relation of a bimorph diaphragm radiator in a multi-resonance frequency region is studied theoretically, and the formula for estimating output sound pressure level for the resonant peak is given. This is also examined experimentally.

High temperature, high vacuum, diffusion bonded piezoelectric motor sandiwch, utilizing intermediate wafflelike layers

Abstract: This invention presents a construction for piezoelectric-type motor devices commonly termed ''''bimorphs'''' and obtains an improved bimorph that is suitable for operation at high temperatures and in high vacuum environments. The bimorph is constructed of two thin flat piezoelectric layers, each of which is plated on the front and back faces with an electrically conductive material by conventional techniques, such as ion plating. This plating preferably consists of successive layers of chrome, copper, and gold. One face of each element functions as an outer electrode. The middle electrode of the bimorph is a thin flat metal which has physical characteristics which match those of the piezoelectric bodies, suitably molybdenum. The molybdenum sheet is copper plated on both sides. This electrode is sandwiched between the two piezoelectric layers. However, sandwiched between each of the piezoelectric layers and the plated middle electrode is a thin layer of electrically conductive material, suitably gold, having a wafflelike or indented lattice surface configuration. These elements are sandwiched together as indicated and are diffusion bonded together to form a unitary mass. One representative application is the use of the bimorph as a driving mechanism in tuners located within the evacuated regions of microwave tubes, such as the coaxial magnetron. Additionally, because the construction retains its operational characteristics in high vacuum environments without outgassing, the motor mechanism is suitable for application in high vacuum electron tubes and in outer space.