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Bimorph

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


Papers
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Patent
30 Jul 2008
TL;DR: In this paper, a multilayer bimorphic sensor with an electrically-conductive first contact on a substrate and a bimomorph beam anchored to the substrate is described.
Abstract: A bimorphic structure responsive to changes in an environmental condition, sensor structures incorporating one or more of such bimorphic structures, and a method of forming such bimorphic structures. The sensor structure has an electrically-conductive first contact on a substrate, and a bimorph beam anchored to the substrate so that a portion thereof is suspended above the first contact. The bimorph beam has a multilayer structure that includes first and second layers, with the second layer between the first layer and the substrate. A portion of the first layer projects through an opening in the second layer toward the first contact so as to define an electrically-conductive second contact located on the beam so as to be spaced apart and aligned with the first contact for contact with the first contact when the beam sufficiently deflects toward the substrate.

14 citations

Journal ArticleDOI
TL;DR: In this article, a model is proposed for predicting the deflection of bimorph cantilevers made of a shape memory alloy film deposited onto solid substrates, by taking into account the changes in the thermal and elastic properties of the film during the martensitic phase transformation.
Abstract: A model is proposed for predicting the deflection of bimorph cantilevers made of a shape memory alloy film deposited onto solid substrates, by taking into account the changes in the thermal and elastic properties of the film during the martensitic phase transformation. The zero actuation reference temperature is the deposition or annealing temperature, with the film in the austenite phase. On cooling from this point, the thermoelastic stress building up in the bimorph causes bimetal-type behavior until the onset of the austenite–martensite transformation, which now controls the actuation up to its completion, when the bimetal actuation reappears. By adapting the classical bimetal thermostat model to the case when one component undergoes martensitic transformation, the deflection during heating and cooling is calculated by averaging the isostrain and isostress phase distribution bounding approximations; the case of a Ti50.1Ni49.9 film/Si was examined. Predictions in good agreement with the recorded deflection of a Ti49.2Ni50.8/Si cantilever (up to a temperature shift explained by composition change and stress developed in the film during the transformation) resulted, indicating a strong effect (attributed to the differences between the elastic and thermal constants of the two phases) of the martensitic phase transformation on the deflection slope and sign.

14 citations

Journal ArticleDOI
TL;DR: In this article, a two-layered plate of AlN with inclined c-axes was proposed for piezoelectric gyroscope application, which can be used to measure the angular rate of the rotation.
Abstract: We propose a new structure for piezoelectric gyroscope application. It consists of a two-layered plate of AlN with inclined c-axes. Through a theoretical analysis, it is shown that when the plate is electrically driven into thickness-shear (TSh) vibration in one direction and is rotating about the plate normal, the rotation causes a TSh vibration in a perpendicular direction with an electrical output which can be used to measure the angular rate of the rotation. Since AlN can be made into thin film devices much smaller than conventional crystal acoustic wave devices, the proposed gyroscope can be made much smaller than existing piezoelectric gyroscopes. The structure can also work with other crystals of class 6mm such as ZnO and polarized ceramics.

13 citations

Journal ArticleDOI
TL;DR: A resonant operation mode of a new adaptive bending X-Ray optics (ABXO) element based on bidomain LiNbO3 single crystal piezoactuator is studied and described in this paper.
Abstract: A resonant operation mode of a new adaptive bending X-Ray optics (ABXO) element based on bidomain LiNbO3 single crystal piezoactuator is studied and described. Spatial and temporal parameters of X-Ray beam tuning by this element are investigated. Experimental measurements and numerical calculations have been performed for the element functional characteristics: oscillatory spectrum, speed of angular adjustment, angular range of scanning. For the first time, the application of the ABXO element has been tested at a source of synchrotron radiation for controlling the X-Ray beam parameters in time-resolved X-Ray diffraction experiments.

13 citations

Journal ArticleDOI
TL;DR: In this paper, a self-sensing approach was developed for the soft electrothermal actuator, which enables the closed-loop control of the actuator without external sensors.
Abstract: Soft electrothermal actuators have been of particular interest to researchers in soft mechatronic/robotic systems due to their large deformation, lightweight, and low power actuation. Closed-loop control of soft actuators is critical for high-precision applications, due to the nonlinear relationship between actuation voltage and output bending motion. In this article, a resistive self-sensing approach was developed for the soft electrothermal actuator, which enables the closed-loop control of the actuator without external sensors. The self-sensing of the actuator's deformation is achieved by measuring the resistance change of the embedded microfilament heater of the soft electrothermal actuator. When the bimorph electrothermal actuator deflects under the temperature change, its deflection can be detected by the temperature-incurred resistance change of the embedded heater. A closed-loop controller was designed using the self-sensed deflection signal. To handle the different responses of the actuator in the heating and cooling stages, a switching proportional-integral-derivative control algorithm was designed. Specifically, two sets of control parameters were tuned and used for the heating and cooling stages, respectively. The performance of the designed control algorithm was evaluated for step response, tracking of complex wave signals, and disturbance rejection. Compared with the open-loop operation, the closed-loop controlled actuator demonstrated a much more rapid and accurate response (the rising time and settling time were reduced over 80%) and excellent tracking and disturbance rejection capabilities.

13 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202358
2022116
202191
202090
2019123
2018117