Bimorph

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

Wavelength-selective and rebound-able bimorph photoactuator driven by a dynamic mass transport process

Abstract: We fabricated wavelength-selective bimorph film photoactuators based on selective light absorption of Au nanocrystals. The dynamic mass transport of water in a chitosan layer leads to ultra-high sensitivity to temperature and a unique post-irradiation rebound behaviour. This work may provide a new design strategy for producing photoactuators with improved performance.

Theoretical and experimental investigation of a 1:3 internal resonance in a beam with piezoelectric patches:

Abstract: Experimental and theoretical results on the nonlinear dynamics of a homogeneous thin beam equipped with piezoelectric patches, presenting internal resonances, are provided. Two configurations are considered: a unimorph configuration composed of a beam with a single piezoelectric patch and a bimorph configuration with two collocated piezoelectric patches symmetrically glued on the two faces of the beam. The natural frequencies and mode shapes are measured and compared with those obtained by theoretical developments. Ratios of frequencies highlight the realization of 1:2 and 1:3 internal resonances, for both configurations, depending on the position of the piezoelectric patches on the length of the beam. Focusing on the 1:3 internal resonance, the governing equations are solved via a numerical harmonic balance method to find the periodic solutions of the system under harmonic forcing. A homodyne detection method is used experimentally to extract the harmonics of the measured vibration signals, on both configurations, and exchanges of energy between the modes in the 1:3 internal resonance are observed. A qualitative agreement is obtained with the model.

High dynamic range thermally actuated bimorph mirror for gravitational wave detectors.

Abstract: Adaptive optics are crucial for overcoming the fabrication limits on mirror curvature in high-precision interferometry. We describe a low-cost thermally actuated bimorph mirror with 200 mD linear response, which meets dynamic range and low aberration requirements for the A+ upgrade of the Laser Interferometer Gravitational-wave Observatory (LIGO). Its deformation and operation limits were measured and verified against finite element simulation.

Optical shutter for spectroscopy instrument

Abstract: Spectroscopy apparatus for spectrochemical analysis of a sample having an excitation source (60) for providing spectral light (62) of the sample for analysis. The spectral light (62) is analysed via an optical system (64-66-68) that includes a polychromator (70, 74-80) and solid state multielement array detector (82). The elements (i.e. pixels) of the detector (82) are serially read by means (84) to provide light intensity measurements as a function of wavelength. A problem is that the elements (pixels) of the detector (82) continue to accumulate charge during the serial read-out. This is avoided by providing an optical shutter (72) for blocking the spectral light (62) whilst elements (pixels) of the detector (82) are being serially read. Shutter (72) has a piezoelectric actuator which is preferably a bimorph mounted as a cantilever. It is preferably located adjacent to the entrance aperture (70) of the polychromator. Bimorph structures for the actuator and drive and protective circuit arrangements are also disclosed.

Response function calculation and sensitivity comparison analysis of various bimorph deformable mirrors

Abstract: Analysis of the response function for various possible bimorphtype deformable mirrors is presented by numerical calculation. Using this response function, sensitivity comparison of a five-layer bimorph with two- and three-layer structures is carried out. It is shown that the displacement of a bimorph deformable mirror surface reduces when the number of layers increases, and the displacement is closely related to the distance of the control layer from the median plane. The farther electrode contributes the larger deformation on the surface. Furthermore, for a fixed position of the control layer, the displacement is directly proportional to the loading voltage and inversely proportional to the square of the thickness of the PZT layer, and it increases about 1.4 times when the area of the electrode doubles. (c) 2007 Optical Society of America.