1,721,000 research outputs found
Thick-film printed PZT actuator and polymer masking layers for micromachined silicon devices
No full textA novel multi-degree-of-freedom thick-film ultrasonic motor
No full textThis paper describes a new multi-degree-of-freedom (MDOF) ultrasonic motor that comprises few parts and is based on low-cost thick-film technology. Conventional ultrasonic motors using bulk lead zirconate titanate (PZT) or thin-film PZT layers are relatively expensive at the present time. Thick-film printed PZT technology provides the opportunity to reduce the costs of ultrasonic motors. To demonstrate the feasibility of this approach, an ultrasonic motor was fabricated from alumina using thick-film printed PZT actuators. The thick-film PZT and electrode layers were printed on a thin alumina plate and a tiny cylinder mounted at its centre. This cylinder magnifies the lateral displacement of the stator, holds the spherical rotor and transmits the driving force to the sphere. Three bending vibrations, B22, B30, B03, of the plate were applied to rotate the sphere. Sufficient displacements for rotating the sphere were obtained near the resonance of B22 by applying an excitation voltage of 200V peak-to-peak via a three-phase drive circuit. Rotations in three orthogonal directions have been observed by controlling the phase of the driving signal to the PZT electrodes and a MDOF ultrasonic motor was successfully realised
Thick-film magnetostrictive material for MEMS
No full textInitial studies on a novel thick-film magnetostrictive material are presented in this letter. The screen printable thick-film is based upon the giant magnetostrictive material Terfenol-D. The development of the paste and of a suitable measurement system is described. Initial values for the magnetostriction of the thick-film are reported and compared with those of other composite magnetostrictive materials
Silicon micromachining processes combined with thick-film printed PZT actuators for MicroElectroMechanical systems
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Processing of PZT piezoelectric thick-films on silicon for microelectromechanical systems
No full textPerformance improvement of a vibration-powered electromagnetic generator by reduced silicon surface roughness
No full textThis paper reports on a chemical polishing process suitable for p-type medium to high resistivity (17-33 Ωcm) silicon substrates. The chemical polishing process using an HNA solution of ratio 27:43:30 (hydrofluoric, fuming nitric, and acetic acids respectively). The process has been applied to the fabrication of a micromachined electromagnetic generator to reduce the sidewall surface roughness of the device after Deep Reactive Ion Etching (DRIE). The microgenerator converts external ambient vibration into electrical energy by electromagnetic transduction. Power output is limited by the maximum amplitude of movement which is in turn limited by the fracture strength of the etched silicon. By applying the polishing etch to the devices, the mechanical strength of the silicon structures increased from 2 N to 5.5 N (similar to 175% increase)
Silicon micromechanical resonator with thick-film printed vibration excitation and detection mechanisms
No full textThe formulation and processing of a thick-film magnetostrictive material
No full textIn this paper the fabrication process for a screen-printable magnetostrictive thick-film material based upon the giant magnetostrictive material, Terfenol-D, is reported. Factors affecting the magnetostriction of the printed thick-film have been identified, and suitable parameters selected to yield a functional thick-film. The evaluation process used to compare the magnetostrictive thick-films is also detailed and a magnetostriction of 4.4ppm for an excitation field of 11.5 kA/m is recorded. This value is compared to other composite materials, and potential routes for improvement of the magnetostrictive thick-film material identified
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