Bimorph

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

Piezoelectric bimorph charge mode force sensor

Abstract: In this work, an analytical model, a finite element analysis and measured results for a planar, parallel and symmetrical piezoelectric bimorph structure are presented. The bimorph consists of two rectangular piezoelectric strips that are connected back-to-back on a thin metallic centre electrode. The bimorph is intended to be used as a millinewton range force sensor with dynamic excitation. The bimorph is modelled with a static, analytical expression for generated charge, voltage, displacement and force that correspond to the deflection of a freely oscillating piezoelectric bimorph. Also, a case where the movement of the bimorph is blocked is analyzed. A circuit that is used to actuate the bimorph is presented, as well as the measured results from the actuator and the sensor side of the bimorph in both free oscillation and blocked cases. The measurement results show a reasonably good agreement with the analytical model and very good agreement with the FEM model. Force sensor setup and a way to measure the force inflicted on the bimorph are also presented, as well as the force response of the bimorph against a commercial piezoresistive force sensor.

Performance improvement of optical actuator by double side irradiation

Abstract: This study is intended to improve the photoresponse of an optical actuator with a bimorph PLZT element. Known optical actuators have multiple merits for converting light energy to driving energy but have a slow response speed and large hysteresis. A method developed by us for exposing both sides of the bimorph element to light has been proved through a series of experiments that the response speed is increased and the hysteresis is reduced thus improving the photoresponse. More particularly, an optical servo system was fabricated for implementing the method and subjected to optical servo tests with PI control. As a result, the PI control was performed with much ease when both sides of the bimorph PLZT were irradiated indicating an advantage of the method. >

Bimorph‐driven x–y–z translation stage for scanned image microscopy

Abstract: We have developed an x–y–z scanning stage for mechanically scanned microscopy. The stage is constructed of ‘‘double‐S’’ mode piezoelectric bimorphs. The prototype unit has a deflection sensitivity of 0.3 μm/V and a travel in each of the three axes of ±60 μm. The lowest mechanical resonances of the stage are at 190, 220, and 360 Hz, corresponding to the x, y, and z axes of the stage, respectively. The noise level of the stage, when mounted on an isolation table, is ∼0.1 nm. The performance of the stage can be understood in terms of a simple lumped element model which can be used to optimize such stages for particular applications.

Piezoelectric speaker, speaker device and tactile feedback device

Abstract: When a piezoelectric speaker, which has a bimorph structure, for example, and is configured by using a piezoelectric sheet having a predetermined stretching axis and made of a chiral polymer, is fixed on a whole circumference, an appropriate vibration is hindered, so that it cannot function as a speaker. An electrode (17) formed on opposing main surfaces of a piezoelectric sheet (12, 13) having a predetermined stretching axis and made of a chiral polymer is divided into four electrode portions (E1 to E4) by a plurality of dividing lines (21a, 21b, 22a, 22b) extending in a radiation direction. The four electrode portions (E1 to E4) are distributed along the outer peripheral portion except for the central portion of a vibration region 15. Voltage is applied to the respective four electrode portions (E1 to E4) in such a manner that electric field vectors generated in the thickness direction of the piezoelectric sheet (12, 13) direct in opposite directions between the adjacent ones of four sheet portions of the piezoelectric sheet (12, 13) to which voltage is applied by the electrode portions (E1 to E4).

Excimer laser ablation of PZT thin films on silicon cantilever beams

Abstract: Laser ablation was used to realise piezoelectric films for use in a low-voltage cantilever bimorph actuator structure Neodymium-doped lead zirconium titanate (PZT) targets were ablated by a pulsed XeCl excimer laser (wavelength 308 nm) The deposited films showed a better morphology than those ablated using a Nd:YAG laser Since the deposited films had high density and small particulate size it was possible to produce a capacitor structure without causing short circuits during the second electrode deposition The depositions were made onto the inner electrode layer on the silicon substrates (thickness 50 μm) at a distance of 20 mm between substrate and target using a laser beam fluence of 1 J/cm2 Growth rates were typically 3 A/s Films were analysed by EDS, XRD and Raman measurements Both the target density and the beam intensity were important in determining the film composition The as-deposited PZT films were amorphous Optimising the annealing conditions resulted in trigonal perovskite being achieved as the main phase Direct current bending characteristics of the low-voltage bimorph cantilever element structure were measured as a function of voltage using a Michelson interferometer