Katsumi Tanino

Reversible shape memory alloy film fabricated by RF sputtering

Abstract The fabrication and processing of an actuator with a TiNi Shape Memory Alloy (SMA) film are discussed and demonstrated. TiNi SMA films were deposited by using sputter deposition techniques, patterned and etched. These films were solution-treated and aging-treated, and then an inverse force layer of chromium was deposited on a SMA film. The frequency response of the beam type actuator was measured by resistance heating. The maximum amplitude was in proportion to the inverse force, and was therefore controlled by chromium thickness. The maximum displacement slightly decreased with an increase of frequency. The minimum displacement suddenly increased at more than 0.1 Hz, then showed a stability over 5 Hz. The maximum displacement was not decided by chromium thickness but TiNi thickness, because thickness of the latter was fifteen to forty times larger than that of the former. Because the frequency response depended on the heat radiation of an actuator, TiNi thickness was the most important factor to...

Functionally Gradient NiTi Films Fabricated by Sputtering

The processing of homogeneous NiTi film has already been reported, but not that of heterogeneous NiTi film. The deposition and processing of functionally gradient films (FGF) of NiTi are discussed and demonstrated. NiTi-FGF were fabricated by RF magnetron sputtering with control of the input power to a titanium target. Films were heat-treated to induce crystallization and memorization. The characteristics have been investigated using a differential scanning calorimeter (DSC) and an electric resistance meter, respectively. The films that were solution-treated at 700° C had a gradient composition, and they showed two types of crystal structure, namely, a nickel-rich layer and a titanium-rich layer in the film. The entire NiTi-FGF transformed gradually and the temperature range between the start and finish of transformation was twice that of homogeneous film. It was verified that motion of FGF could be controlled easily by current intensity.

Low-Temperature Sintering of Pb(Mg1/3Nb2/3)O3–PbTiO3 Ceramics with Addition of PbO–Bi2O3

The Low-temperature sintering has been examined in the preparation process of Pb(Mg1/3Nb2/3)O3–PbTiO3 ceramics. The sintering temperature could be reduced from 950° C to 800° C by addition of PbO–Bi2O3 as a lower-melting-point sintering aid. The dielectric constant of 16000 and loss tangent of 0.02 were obtained for Pb[(Mg1/3Nb2/3)0.95Ti0.05]O3 ceramics fired at 800° C with 2 mol% of PbO–Bi2O3. These low-temperature sintering dielectric materials are very promising for use in fabrication of printed thick-film capacitors.

Fabrication Technique for Preparing Nanogap Electrodes by Conventional Silicon Processes

A fabrication technique for preparing nanogap electrodes, such as a gold (Au) nano electrode, using conventional silicon (Si) processes–photolithography, etching, thermal oxidation and deposition–is proposed. Stencil substrates are prepared using the Si processes. Then, without requiring complicated technology, nanogap structures can be formed using the technique. Numerous kinds of materials can be selected as an electrode. The mass production of a sensing device for the detection of deoxyribonucleic acid (DNA), or a so-called DNA chip, can be realized at a low cost.

Preparation of Dielectric Thin Films of Pb[(Mg1/3Nb2/3)0.9Ti0.1]O3 by Screen Printing Method

Dielectric thin films of Pb[(Mg 1/3 Nb 2/3 ) 0.9 Ti 0.1 ]O 3 were obtained by a screen printing method. A screen-printable dielectric paste was synthesized using submicron-sized powder and a metalorganic compound, which acted as an organic vehicle and a sintering aid. The crystal structure and dielectric properties of the thin films were greatly influenced by the bottom electrodes and substrate materials and also by firing conditions.

Trapping and Collection of Lymphocytes Using Microspot Array Chip and Magnetic Beads

A microspot array chip, which has microspots of a magnetic thin film patterned on a glass substrate, was fabricated for trapping individual cells and for measuring their cellular response. The chip was easily fabricated by conventional semiconductor fabrication techniques on a mass production level as a disposable medical device. When a solution of lymphocyte-bound-magnetic beads was poured into the magnetized chip, each lymphocyte was trapped on each microspot of the magnetic thin film. The trapped cells were easily recovered from the chip using a micromanipulator. The micro-spot array chip can be utilized for arraying live cells and for measuring the response of each cell. The chip will be useful for preparing on array of different kinds of cells and for analyzing cellular response at the single cell level. The chip will be particularly useful for detecting antigen-specific B-lymphocytes and antigen-specific antibody complementary deoxyribonucleic acid (cDNA).

Preparation of PbTiO3 Thin Films by Screen Printing Method

PbTiO3 thin films were obtained by the screen printing method on Au bottom electrodes using Si(100) substrates. The screen-printable paste was synthesized from the Pb–Ti complex alkoxide and abietic acid. The optimum conditions of amount of PbO content in the paste and annealing temperature were investigated to prepare the ferroelectric thin film. The remanent polarization and coercive field of this thin film were 8 µ C/cm2 and 110 kV/cm, respectively. Pyroelectric coefficient was 0.67× 10-8 (C/cm2·K) after poling.