Jun Akedo

Actuation Properties of Lead Zirconate Titanate Thick Films Structured on Si Membrane by the Aerosol Deposition Method.

The results of the direct deposition of lead zirconate titanate [Pb(Zr0.52, Ti0.48)O3] (PZT) thick film on a Si-based structure are presented. The construction of a bottom electrode is very important for successful deposition. The actuation properties of PZT on the Si membrane were investigated. For a 6.2×6.1 mm2, 65-µm-thick Si membrane driven by a 4.7×4.3 mm2, 13-µm-thick PZT layer, the deflections, which were 1.5 µm upon applying 52 V at nonresonance frequency and 22 µm upon applying 8 V at resonance frequency, were measured.

Electrical properties of direct deposited piezoelectric thick film formed by gas deposition method annealing effect of the deposited films

Abstract Ultrafine particles jetting with the velocities of several hundreds m/s are accumulated on the metal and ceramic substrate via impact adhesion. Recently, the application of this phenomenon as a thick film formation method has been investigated for micro electro mechanical systems (MEMS) and micro devices. The gas deposition method is one of the thick film formation method based on impact adhesion of ultrafine particle. In this paper, the optimum annealing condition for the deposited Pb(Zr,Ti)O3 film with thickness over 10 μ m is reported. For the deposited films after annealing at 600°C for 1 hour, the remanent polarization of 20 μ C/ cm2 and the coercive filed of 44.7kV/cm was obtained.

Characterization and application of jet-printed thin PZT layers for actuation of MEMS

Although piezoelectric thin films are of great interest for actuator application in MEMS, deposition of PZT films with thicknesses between 5 and 100 micrometers has been hardly possible. It is therefore the goal of this paper, to investigate the properties of PZT-films of this thickness deposited by the recently introduced Jet-Printing System, especially concerning an application in micro actuator devices. First, PZT layers of thicknesses between 5 and 80 micrometers have been Jet-Printed on different substrates to investigate the compatibility of the deposition method with standard materials used for MEMS. The relative dielectric constant of the layers could be determined between 20 and 550, depending on annealing and deposition conditions. Following, on thin beam-shaped steel substrates PZT layers of 10 to 40 micrometers thickness were deposited. SInce the samples showed deformation caused by technology-introduced stress, the stress value is calculated by means of FEM calculation, and methods for avoiding and compensation of the deformation are introduced. Using the beam-shaped samples, for the first time the piezoelectric constant of the Jet-Printed PZT-layer was calculated to 20...30 10-12 C/N from laser measurements of static and quasi-static beam deflection, and therefore piezoelectric actuation capability could be proofed directly.

New functional ceramic deposition method for MEMS

Abstract The PZT, NiZn-ferrite and TiO2 ceramic films with thickness range of 1 to 100 μm were deposited by focusing a jet flow of ultra-fine particles of these materials on a substrate. According to the XRD observation, the as-deposited films have randomly oriented polycrystalline structure, what is the same as the raw material crystal structure of the ultra-fine particles. Ferroelectricity of the as-deposited PZT film was obseved.

Metal-based Optical MEMS Scanning Devices Using Lead-Free Piezoelectric Sheets Prepared by Aerosol Deposition

We demonstrate metal-based lamb-wave resonant optical MEMS scanning devices actuated by aerosol deposition (AD) piezoelectric film and report their temperature properties and durability. Metal-based structure was introduced to reduce the production cost and to improve the optical scanning performance, simultaneously. The optical scanning devices with large mirror size as well as high scanning angle were fabricated. A high optical scanning angle (more than 60 °) and a high resonant frequency (more than 25 kHz) were achieved in ambient air without vacuum packaging. The resonant frequency and the scanning angle do not have any changes during life test of approximately 50,000 hours. In this report, BaTiO3 (BTO) thick film as a lead free piezoelectric material was prepared by AD process for a piezoelectric exaltation source of scanning devices. Piezoelectric d31 of BTO-AD film was approximately −138 pm/V. The performance of optical scanner driven by AD-BTO thick film was comparable with that of BTO bulk materi...

Application of jet-printed PZT layers for actuation of small beams, membranes and a 2D scanning actuator

To close the technological thickness gap between vary thin PZT-layer deposition and bulk PZT, a new technology called Jet Printing has been introduced recently, which can be used to deposit layers between 5 and 100 micrometers thickness. This technology is used for the first time to fabricate bimorph actuator elements suitable for actuation purposes in MEMS. At first, 10 to 40 micrometers thin PZT layers are deposited on beam shaped structures made of 30 micrometers thick steel. This basic actuator beams were stimulated by an AC voltage, and the reflected laser beam showed reasonable dynamic deflection angels of about 5 degrees maximum. Secondly, deposition on anisotropically etched silicon membranes with varying thickness from 25 to 125 micrometers was carried out. It appeared, that at a membrane thickness lower than 50 micrometers technologically effects can break the membrane. However, for membranes thicker than that, direct deposition after anisotropic etching could be applied successfully, and dynamic deflection of this membranes could be proofed by laser interferometric measurement. Finally, a small structure capable of diverting a laser beam and carrying out 2D scanning was designed and fabricated from 30 micrometers thick steel using laser ablation. The scanner is actuated by four actuator beams, on which 30 micrometers thick PZT has been Jet Printed as the actuating material. The electrodes on the beams can be stimulated separately, and therefore control the scanning direction. Experiments showed the capability of the structure to be actuated, and deflection angels up to 5 degrees could be measured.