This paper proposes a new polishing tool used for the high efficiency thinning process of extremely thin quartz wafers and investigates its fundamental performance on the polishing of quartz material experimentally after its internal structure has been clarified by microscopic and SEM observation. This kind of tool is prepared by freezing a water-based MCF(Magnetic Compound Fluid)polishing liquid, a intelligent fluid composed of water-based MF (Magnetic Fluid), iron powder, abrasive particle and α-cellulose, with liquid nitrogen, and thus reacting to magnetic fields. An experimental apparatus developed previously was employed for the MCF polishing experiments of quartz wafers with dimensions of φ30mm×t0.75mm. The obtained results showed that (1) MCF polishing tool has much greater material removal ability after freezing than that before freeing; (2) Higher material removal rate can be obtained by using a frozen MCF polishing tool with larger abrasive particle but in this case the surface roughness gets worse; (3) Highest material removal rate and best surface roughness can be obtained when the percentage of water in the frozen MCF polishing tool was around 34.7%.

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This report describes an application of magnetic compound fluid (MCF) rubber to a material for microwave heating. The MCF rubber is one of several new composite materials utilizing MCF as a newly developed magnetic responsive fluid developed by one of authors. The temperature of water in a PP container enveloped by the MCF rubber in a microwave oven was measured over the various mass concentrations of magnetic particles in the MCF rubber. By comparing to the temperature of the MCF rubber, there is an optimum mass concentration on increasing or decreasing temperature of the water. A part of the experimental results can be explained by a simple microwave heating theory and the experimental data of complex permittivity and permeability of the MCF rubber qualitatively. In the present study, the iron particle is better in the microwave heating than copper or nickel particles. The MCF rubber is useful for the material for microwave heating in a microwave oven.

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The MCF conductive rubber, combining the MCF in a silicon-oil rubber, has been developed with Shimada laboratory a few years ago. Recently, by means of the MCF electric conductive rubber, we are developing a haptic sensor for the applications to a robotic finger, artificial skin, and so on. For the purpose of the applications, it is important to understand various characteristics of the MCF electric conductive rubber, for example, electric characteristic. In this paper, at first, we observed the change of its electric resistance when the MCF rubber is compressed to have a small deformation. Next, we made a haptic sensor utilizing the MCF electric conductive rubber. Finally, we pointed out that proposed sensor by us is useful to sense a small pressure.

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This paper describes the application of liquid particles to the measurement of the airflow around the forewing of the dragonfly, Sympetrum frequens. The particles with the diameter of approximately 10 μm were obtained by heating a mixture of glycols and distilled water. They were scattered as tracer particles in a wind tunnel. A PIV system was used to analyze the airflow around the dragonfly forewing with Re = 1.1 × 103. On the other hand, a three-dimensional dragonfly forewing model was constructed for a numerical simulation. This simulation was used to obtain the velocity distributions around the model as well as the aerodynamic characteristics such as lift and drag coefficients. The experimental velocity results were in a good agreement with those of the simulation. Therefore, it was confirmed that the use of liquid particles comprising glycols was suitable for the analysis of low Reynolds number flows by the PIV system.

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A magnetic silicon rubber membrane is a rubber membrane solidified with a magnetic compound fluid. In this study, vibration properties of a coupled system of a circular magnetic silicon rubber membrane and a magnetic fluid layer in alternating magnetic fields are investigated. Under alternating magnetic field, vibration of the magnetic rubber membrane has phase-delay against the alternating magnetic field. The delay is increasing as the frequency becomes higher. At the range of low frequencies of alternating magnetic field, the amplitude of vibration of the membrane keeps constant value. Vibration properties are different from those of the coupled system of nonmagnetic rubber membrane and magnetic fluid. The coupled system of magnetic rubber membrane and magnetic fluid oscillates sinusoidaly by applying alternating magnetic field.

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It is well-known that a high frequency magnetic field and a static magnetic field have a function to suppress a surface disturbance on a molten metal surface. However, it is not clarified until now that the magnetic field has a suppression function of the disturbance or not when the shielding parameter is around unity. In this study, the surface disturbance behavior on the molten metal with the alternating magnetic field has been investigated, in which the ratio of an electromagnetic skin layer to the metal depth, δ/h is set between 0.25 and 1.5. In the case that the ratio is unity, the alternating magnetic field does not suppress standing wave amplitude excited artificially on the molten metal. However, higher frequency magnetic fields of the ratio,δ/h=0.25 and 0.58 decrease the amplitude of the standing wave by 6-7%. The surface wave decays quickly by imposing the alternating magnetic field within all the ratio range from 0.25 to 1.5. The damping constant of the surface wave increases by increasing the intensity of the magnetic field and the frequency.

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This report describes the technical proposal as the first step on the polishing of inner capillary wall utilizing a magnetic compound fluid (MCF) combined by a magnetic fluid and magneto-rheological fluid. When perform the proposed polish, we flow in MCF included nonmagnetic abrasive to nonmagnetic inside a capillary and impress a rotation magnetic field with three-phase alternating current to vertical direction of capillary axis. We performed polishing experiments for a stainless steel capillary of 2mm inside diameter and investigated the influence of abrasive density and magnetic density. Although the polishing effect is lower but the vanishing action is showed. To understand the polish mechanism we have done visible experiment and magnetic field analysis, and investigated the abrasive behavior. We found the abrasive always gather to a place where magnetic field strength is small such as pushed out from the cluster and the abrasive do relative rotation motion. From the results, we consider distribution of clusters gave the abrasive processing force and magnetic field is important in this type of polish.

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In this study, we investigated the effects of ingredient ratio of polishing liquid and magnetic field distribution on the polishing inner surface of a tube utilizing MCF (Magnetic Compound Fluid) and discussed the polishing mechanism from the viewpoint of hydrodynamics. In the polishing, we filled the MCF involved abrasive particles in the tube and applied a rotational magnetic field vertically to the tube axis. In order to clarify the polishing mechanism, we conducted on the optical observation of the abrasive particles’ behavior and measured the pressure distribution on the inner surface of the tube hydrodynamically. Because the effect of the fluid’s ingredient on the polishing depends on the abrasive particle’s size, the size of the abrasive particle is needed to be more than that of the iron particles in the fluid. In addition, we clarified that the magnetic field distribution influences the polishing process strongly. We clarified that the effective magnetic field distribution for the polishing is at the most apart from the centerline of the magnetic field. This position has large decreasing magnetic flux and ratio of magnetic flux density, and the pressure distribution has a need for polishing. The pressure distribution shows a shape with flat in a valley.

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A swirl motion of a liquid jet has high mixing ability and it is useful for wastewater treatment. Water model experiments have been carried out to understand the occurrence condition and basic characteristics of a swirl motion of a wastewater jet generated by a J-shaped lance in a cylindrical vessel. As the water injected into the vessel is not circulated with a pump, the bath depth increases continuously with a lapse of time. In the initial stage of water injection the water jet rises straight upward. When the bath depth exceeds a certain critical value, the jet oscillates in the radial direction. With a further increase in the bath depth, two types of swirl motions appear: shallow-water and deep-water wave types. The period and amplitude of the swirl motion of deep-water wave type are measured with a high-speed video camera.

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It is important to know mechanical properties of micro structures fabricated as a micro machine component by micro-stereolithgraphy (μSL). In the previous study, we reported that elastic modulus of micro cantilevers fabricated by μSL is controlled by irradiation laser power and postcure processing time. In this study, we investigate the correlation between the irradiation laser power and the inner structure of the micro cantilever, which consists of periodic density distribution caused by laser scanning. The structure inside the micro cantilever made under the condition of various fabrication conditions is observed using a digital microscope and a polarizing microscope. Results show that the density of periodic inner structure has an affect on the elastic modulus of the microstructure.

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Recently, the effect of heat conduction has been considered to be a big problem in thermoelastic stress measurement. Then, the effect of heat conduction was investigated by the experiment which changed the material, thickness of the specimen and frequency of a cyclic load. Though the infrared hybrid method was developed to separate individual stress components, it has the effect by heat conduction in the infrared stress measuring method. Therefore, an error will arise in the infrared hybrid analysis. Then, the system which corrects the error by the inverse analysis was developed. Thereby, the accuracy of the stress intensity factor was able to be raised. Furthermore, the accuracy of hybrid method considering to heat conduction was discussed in comparison with the 3-D finite-element analysis and 2-D hybrid method.

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