Bimorph

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

A multi-degree-of-freedom micromirror utilizing inverted-series-connected bimorph actuators

Abstract: An ove lm ulti-degree-of-freedom electrothermal micromirror design that uses thermal inverted-series-connected (ISC) bimorph actuators is presented. The ISC bimorph actuators eliminate problems observed in previous designs that use single bimorph actuators. The micromirror can operate in one-dimensional (1D) piston-mode and two-dimensional (2D) tilt-mode. Analytical models for the piston-mode and tilt-mode actuations are shown and are compared to FEM simulation results. The device was fabricated using the AMI 1.5 µ mC MOS (complimentary metal-oxide semiconductor) process followed by a post-CMOS micromachining process for device release. The displacement versus temperature of the micromirror was measured experimentally over a range of temperatures and compared to analytical and FEM simulation results .E xperimental results showed that the micromirror displaced by 56 µ ma t an applied temperature 150 ◦ C. The integrated polysilicon heaters were open-circuited during the post-CMOS microfabrication. The failure was caused by pinholes in the metal layers that allowed etchants to attack the polysilicon layer during post-CMOS microfabrication.

Resonant manifestation of intrinsic nonlinearity within electroelastic micropower generators

Abstract: This letter investigates the nonlinear response of a bimorph energy harvester comprised of lead zirconate titanate (PZT-5A) laminates. For near resonant excitations, we demonstrate significant intrinsic nonlinear behavior despite geometrically linear motion. Fourth order elastic and electroelastic tensor values for PZT-5A are identified following methods recently published concerning a PZT-5H bimorph. A response trend indicative of a nonlinear dissipative mechanism is discussed as well as the inadequacy of linear modeling. The PZT-5A bimorph exhibits an increased softening frequency response in comparison to PZT-5H. The results contained herein are also applicable to electroelastic sensor and actuator technologies.

Transducer for detecting pressure changes in pipes

Abstract: A transducer for detecting pressure changes in pipes by detecting deformation of the pipes and for converting the pressure changes in the pipes into electric signals includes a piezoelectric element having a bimorph structure as a sensor element. The piezoelectric element is constructed in such a way that an intermediate layer is interposed between two piezoelectic pieces. The element is pressed against the pipe surface by a holder which is sufficiently elastic to allow opposite ends of the piezoelectric element in the circumferential direction of the pipe to elastically abut against the pipe periphery. Thereby the ends of the piezoelectric element can be pressed in tight contact against the outer surfaces of pipes having various diameters, and the internal pressure of the pipes can be detected reliably.

Multifunctional transducer using poly (vinylidene fluoride) active layerand highly conducting poly (3,4-ethylenedioxythiophene) electrode: Actuator and generator

Abstract: Monomorph and bimorph multifunctional transducers such as actuators and generators were fabricated using a piezoelectric poly (vinylidene fluoride) (PVDF) films as the active layer and a highly conducting poly (3,4-ethylenedioxythiophene)∕poly (4-styrenesulfonate) [PEDOT∕PSS (DMSO for solvent)] as the electrode. In order to enhance the adhesion of the films, either the PVDF films or PEDOT∕PSS (DMSO) electrodes were modified using an ion-assisted-reaction (IAR) method. The direct (generator) and inverse piezoelectric (motor) effects as well as the pyroelectric effect in the PVDF-PEDOT∕PSS based devices were observed. The tip displacement of the 12mm by 30mm bimorph device made with the PEDOT∕PSS (DMSO) electrodes was 3.5mm at the resonance frequency with an appled potential of 40Vrms. The sinusoidal output voltage of the bimorph type generator consisting of the PVDF active layers and PEDOT∕PSS (DMSO) electrodes increased with increasing tip displacement induced by a vibrator. A maximum output voltage of 4....

Thermally driven microvalve with buckling behaviour for pneumatic applications

Abstract: The paper presents theoretical and experimental results of a new thermally driven microvalve. In contrast to earlier reported devices with bimorph composition this valve is based on the buckling effect of a heated pure silicon bridge structure. Simulation, fabrication and experimental results are presented. Analytical and finite-element calculations of the thermomechanical behaviour are performed. Prototypes of this first valve design operate with inlet pressures up to 1.0 bar showing flow rates of more than 700 ml/min. The measured switching time is about 15 ms which is extremely low for thermal principles. The power consumption of this valve is between 1 and 4 W.