This paper describes a contact-type airflow sensor, based on insects' sensillar seta. Some insects such as crickets begin escape behavior by sensing a minute airflow with sensillar seta. The sensor consists of a metal cantilever and an insulation layer. Air flow bends a hair connected to the cantilever, which causes the deflection of the cantilever and the contact with the substrate. The wind tunnel tests showed the airflow sensor was able to detect the velocity of wind from 0.1m/s to 1m/s depending on the cantilever lenglth. The sensor is mounted on the surface of an insect' robot.

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In this paper, we propose a novel microfabrication technique without assembling process including alignment and bonding for 3-D micro-molds in microfludics. The proposed process can integrate microchannels with free path, orifices, and openings by using the inclined/rotated UV lithography with a characteristic single-mask of whole image exposure in a short period of time. In order to confirm the validity of the proposed fabrication process, we fabricated a micro-electroporation device with two flow channel to introduce cell and substance suspension, six orifices to fix the cell, two inlets and one outlet by using single-mask multidirectional photolithography. The immobilization efficiency of cells were investigated in the fabricated devices.

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This paper describes a flapping robot based on a dragonfly. Flapping flight enables the robot to hover and take a sharp turn like an insect. The flapping motion was produced by a four-bar linkage and a slider-crank mechanism actuated by a DC motor. The body of the robot was fabricated from a brass plate using MEMS techniques. The brass plate was patterned by etching, and then folded out of the plane to assemble the three dimensional structure. The wing with veins was also microfabricated from an aluminum plate and a parylene film. The robot flapped at 15.2Hz and generated the lift force of 11.4 mN.

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In this study, we investigated influence of the microchannel width on a microdevice for single-cell manipulation. The proposed device was fabricated by the Single-Mask inclined exposure method which can fabricated a lot of micro-holes to fix cells and lower microchannel to load reagent. We estimated the restriction of the fabrication process due to the width of the lower microchannel. Moreover, we proposed a reduction method of the warp of the fabricated device made of the thick permanent film resist to achieve a wide lower microchannel.

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We report a SiO_2 electret for comb-drive actuators that have vertical and narrow gaps. The potassium ion included SiO_2 film was formed on the comb-drive actuator by thermal oxidation. Because the SiO_2 film polarized, the bias-temperature (B.T.) treatment was processed to the actuator. Without applying the bias voltage, the resonance peak was observed by inputting a minute AC signal (1 [V]) in the vacuum. This resonance peak is evidence that SiO_2 Electret was formed. This charging method is possible to apply to energy harvesting devices that use comb-drive actuators.

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We have conducted experiments of operating the force operating joystick to acoustic information. We have established the acoustic control system that feedbacks operating force for realizing target value of joystick operating force. In this acoustic control system, a behavior of operating force is identified using Neural Network system. Effects of learning-parameters on operating force are studied. As a result, time duration to be necessary for identification shortened very much in comparison with previous study.

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We have proposed a system that supports the proficient operation of an electric wheelchair with acoustic information. The audio system provides the electric wheelchair user with acoustic information with the aim of conferring an intuitive feeling of how the wheelchair is operated. To investigate whether or not this audio system promotes efficient operation of the wheelchair, we constructed a sensing system for analyzing the movement of the electric wheelchair. We made a straight-line-course with step and entrance zone to measure the joystick and motion behavior of an electric wheelchair. We repeated a running test of the electric wheelchair for the same test subjects until they improve operation skill. We thereby demonstrated that there is a relationship between the acting on a joystick and vibration. And we also investigated whether or not to listening sounds promotes efficient operation of the wheelchair.

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This paper describes a new method for three-dimensional transportation of liquid droplets using EWOD (Electro Wetting on Dielectric). This method utilizes surface tension and electrostatic forces, which become significant at the microscale. The droplet transported on a vertical or upside down surface is affected by gravity force. In order to reduce the gravity effect, volume of water was reduced and shape and size of electrodes were changed. A water droplet was transported on a inclined surface, and the angle of inclination was changed from 10° to 360° by every 10°. The results show that water droplet can be transported on all inclined surfaces. Horizontal transportation of a droplet on a vertical surface was also made successfully. In addition, the device was also fabricated on a polyimide flexible substrate and a droplet was successfully transported on the curved surface. With these technology, multi-DOF actuation was enabled by using two pieces of flexible device.

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This paper describes water-repellency of the microstructured surfaces, as a basic study for the development of supporting legs of water strider robots. To obtain super-water-repellent surfaces, micro pillars with various shapes were fabricated on silicon wafers by deep RIE (Reactive Ion Etching) and hydrophobic films were coated on the structures. The contact angles of these surfaces were measured and effects of shape, size, height and pitch of the pillars on contact angles were investigated experimentally. The surface with hexagonal micropillars exhibits water contact angle of 168 degrees. Pull-off force and fluid resistance of the water-repellent surfaces against water were also measured. The results show that water repellency has a significant effect on reducing the pull-off force.

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We have developed a numerical method to calculate motion of toner and carrier particles in two-component magnetic brush development system in electrophotography using Distinct Element Method (DEM). A feature of this simulation is that it involves a current conduction in brush of carrier particles. A parallelization technique of the numerical computation was adopted to reduce the calculation time. Calculated results qualitatively agreed to the experimental observations that the amount of developed toner particles increased as the increase of the development voltage and some carrier particles adhered to a photoreceptor drum surface by applying high development voltage.

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In a non-magnetic single-component development system in electrophotography, formation of a thin and uniform toner layer on the development roller is important for obtaining high image quality. We conducted experimental and numerical investigations to clarify the dynamics of toner particles in this process. Two approaches were adopted for the investigation. One is experimental and the other is numerical simulation using the distinct element method. We manufactured a mock-up apparatus consisting of a supply roller, a development roller, and a doctor blade for forming a thin toner layer on the development roller. The thickness, surface roughness, and charge density of the formed toner layer were measured after the doctoring process. It was clarified that the thickness of the toner layer was increased, but the charge density was decreased, by increasing the applied voltage and rotational speed. These findings were confirmed by direct observation of the toner motion in the doctoring area with a high-speed microscope camera. Numerical calculations performed using an improved distinct element method revealed that the elastic energy applied to the toner particles, which is an index of toner degradation, was increased by increasing the stiffness and pressing force of the doctor blade, but decreased when the curvature of the blade tip was large. The present experimental and numerical results can be used to improve non-magnetic single-component development system in electrophotography.

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This paper deals with measurement of real contact area between a rubber roller and a glass plate using a laser microscope having a wide field of view. It is very important to clarify the tribological properties of the rubber rollers for precise paper-feeding in printers and copiers. A real contact area ratio greatly affects local micro-slips. A total amount of real contact area determines a critical friction torque between the roller and the glass plate. The effect of paper debris attached on the roller on the critical friction torque is examined. The paper debris on the roller decreases the amount of real contact area and the critical friction torque.

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This paper describes theoretical and experimental studies of the deformation of paper in a nip unit. It is important to investigate the strain of the paper surface in the nip unit for a precise prediction of the paper transport characteristics. First, the deformation of the neutral plane was modeled by the multi-link model, and the strain of the paper surface was derived theoretically. Next, by an experimental setup of a nip roller mechanics with a short rubber-layered roller and a short steel roller, the strain of the paper surface was obtained experimentally. Finally by comparing the experimental results and numerical ones, the shear modulus of rigidity of paper was identified, and the physical parameter of paper was cleared.

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This paper describes theoretical study of flexible media transportation characteristic of a pair of nip roller mechanisms. Nip roller mechanism which consists of a rubber roller and a steel roller is utilized for paper transportation in copy machines and printers. A pair of nip roller mechanisms holds a sheet of paper simultaneously in order to give a certain tensile force for the paper between two mechanisms. Proposed parameter design method of nip roller mechanisms realizes predetermined tensile force on the paper based on our two-dimensional contact analysis.

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One of the main issues in the development of printers is to achieve sheet-feeding stability with various kinds of sheets and to shorten the development period. In recent years, studies on sheet handling have been performed that enable us to develop a sheet-feeding path efficiently; however, defects resulting from sheet-feeding instability still occur because many defects cannot be treated analytically. In this study, we focused on the paper-wrinkle that was one of the tough phenomena to analyze. A handy geometry model was constructed about the paper-wrinkle based on the observation of the generation process and an alternative characteristic of the wrinkle generation was derived. In addition, the device to visualize the generation process of the paper-wrinkle quantitatively for evaluation of the phenomena was developed, and the validity of the alternative characteristic was verified.

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This paper addresses EMC of an implantable artificial heart connected by a conducting wire (drive line) and influence of the emitted electromagnetic noise on the human body. Conducting wire length and human height may cause electrical resonance. At such times, the current through the conducting wire and the human body could increase conspicuously. We determined the current passing through the human body attached the conducting wire by both FDTD electromagnetic simulation and experimental observation. A cylinder model was used to imitate the human trunk. It was placed at the center of a shield room and subjected to electromagnetic plane waves with wavelengths ranginge from 80 MHz to 1 GHz. Experimental results show that the current through the human body was generally in the range of 0.25-2.3 mA (100-400MHz) with three remarkable current peaks. Simulation results show higher average current and lower peak frequency compared to the experimental results.

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For regenerative medicine, it is important to culture the cell in the collagen fiber aligned artificially. In this study, we examined collagen fiber aligning methods by mechanical strain. First, we carried out the collagen fiber alignment control by tensile strain. As a result, a part of the collagen fibers on the glass substrate can be aligned. Then, we tried the shear strain by sliding of glass plates which sandwiched collagen for aligning the collagen fibers. As a result, it could not confirm the aligning of collagen fibers.

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The heartbeat and respiratory information are often used for monitoring the sleep state. The respiratory measurement is important especially in monitoring the apnea during the sleeping. The most currently used respiration sensors are the thermo sensor and strain-gauge embedded belt sensor. However, these sensors are requested to fix somewhere in the body, which might become a negative effect on sleep itself. In this study, a simple microphone is investigated to measure the breath sound during the sleeping. In this case, how to extract the breath information is a major issue in this study. A new and simple signal processing method for extracting the breath sound is proposed and the efficiency is verified experimentally.

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Estimation method of optimal mount positions of inertial sensor for thigh and crus is described. These positions are estimated by calculating the movement of reflective markers placed on the skin. A Point Cluster Method that is one of the methods for deriving limb segment motion is employed to calculation the movement of markers. The movement of markers is evaluated as displacement and rotation, and the marker position where these values are minimum is estimated as optimal mount position. Five experimental movements were given to five subjects: flexion/extension of knee, counterclockwise rotation of waist, clockwise rotation of waist, flexion of knee medially, and flexion of knee laterally. The experimental results show that estimated optimal mount positions are lateral superior position of thigh and anterior inferior position of crus.

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Human skin, which mainly consists of epidermis, dermis and hypodermis, is the largest organ of a human body. It has a lot of roles, for example, protection function, moisture maintenance function and sensory function. Moreover, it becomes a parameter that shows the health condition and beauty, because the skin is the outermost layer of a human body. A palpation is convenient and it is a useful method to detect prostatic cancer and hypertrophy. But, the palpation is skillful method and the result of the palpation is subjective. And the result is affected easily by mental/physical conditions of the experts and environment, and it is hard to share the result with other people. Therefore, the development of the sensor that can measure the "softness" of the body is demanded. In this paper, relationships between physical properties of measured objects and the "softness" that human feel are investigated for development of a tactile sensor system.

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Palpation is important method for diagnosis. However, it is a subjective method, because diagnosis by palpation depends on skill and experience of doctors. Therefore, an objective palpation method is required. Tanaka et al have developed an active palpation sensor wearable on a finger for detecting prostate cancer. The sensor discriminated the hardness of prostate glands on the clinical tests. However, the sensor blocks feeling of the finger because the sensor part covers a finger pad. Measurement by sensor and palpation by a doctor at a same time will make better diagnosis. In this study, a nail-mounted sensor for measuring hardness of biological tissue with palpation by doctors was developed. Fundamental characteristics of the sensor were examined by using silicone rubber sample with different stiffness. From the results, it is confirmed that the sensor is available of discriminating hardness.

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This paper describes the improvement of a Braille sensor with considering usability. Tanaka et al. have developed a Braille sensor using PVDF (Polyvinylidene Fluoride) film. However, three problems of the previous sensor related to usability are listed. First, it is difficult to move the sensor steadily along Braille lines. To overcome this problem, wheels were mounted to the sensor. Next, it is difficult to fit the sensor guide groove accurately to dots of each Braille row. The sensor guide was improved against this problem. Finally, it is difficult to parallelize the sensor to Braille letters. The sensor grip was changed to solve this problem. In addition, verification experiment of the improved sensor was conducted and it is confirmed that the improved sensor is higher than that of the previous sensor.

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Grounded force-display systems generally suffer the difficulty of workspace restriction. On the other hand, if we utilize an illusion on a sense of contact force, a wearable non-grounded force display system would be developed much easier than without utilizing the illusion. We found an interesting phenomenon, i.e., a kind of illusion from an experiment using a prototype device: a majority of subjects perceive a biased force in either direction even though, facing each other on both sides of a forearm, two sets of external forces are applied to the forearm in equal strength. As for the factors of the phenomenon with the baresthesia, i.e., the sense of pressure, we considered the area effect and the adaptation one. In order to examine the mechanism of this phenomenon, we carried out some experiments to investigate fundamental characteristics with each of the factors. Then, we, furthermore, did some extended experiments where the both factors are mixed, and showed that the baresthesia is well explained by the fundamental characteristics.

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To quantitatively investigate tribological properties of nanometer-thick liquid lubricant films using molecular simulations, we developed a coarse-graining method that is applicable to random copolymers and determined the friction coefficient in the Langevin equation based on spreading measurements of nanometer-thick liquid films on solid surfaces. Using the coarse-graining molecular dynamics, we then simulated behavior of nanometer-thick perfluoropolyether (PFPE) films coated on a solid substrate with respect to the approach and withdrawal of a solid probe. The simulation results showed that the PFPE films exhibited solid-like behavior against high-speed movement of the probe and the elongation viscosity of the PFPE film increased as the films were elongated. At the solid-solid distance of 2 nm, the shear viscosity was evaluated to be 0.33 Pa・s from the speed dependence of the adhesion forces. The consistency with the experimental value of 0.3 Pa・s demonstrates the validity of our simulation method.

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Recently, the head flying height between the slider and the disk becomes to be a few nanometer to improve the recording density of hard disk drives (HDDs). As the head flying height decreases, the slider-disk contacts increase and the role of the ultra-thin liquid lubricant film with 1-2 nm on the disk surface becomes important. In this study, we investigated the surface energy as well as the interaction with water molecules using conventional Z-tetraol2000 and novel lubricants of TA-30, QA-40, QG-40 and QX-40. It was found that the surface energy of novel lubricants is lower than that of Z-tetraol2000 and that the interactions of novel lubricants with water molecules is stronger than that of Z-tetraol2000, depending on the conformation of the lubricant molecules.

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An understanding of tribological properties of molecularly thin lubricant film is necessary to design the head-disk interface (HDI) of high-recording-density hard disk drives. Characteristic conditions of lubricant shearing at HDI are confinement of lubricant molecules in nanometer-sized gap widths and high shearing speeds. In our previous study, we have developed a highly-sensitive shear force measuring method using oscillating optical fiber probe, which we called the "fiber wobbling method", and achieved viscoelastic measurement of molecularly thin lubricant films. However, in the previous experiments, shearing speeds were much smaller than those in HDI. In this study, we achieved higher shearing speed by utilizing the resonant oscillation of the optical fiber probe and could detect viscoelastic responses of molecularly thin lubricant films.

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Raman spectroscopy is effective tool for determining molecular structures of lubricants as well as DLC crystal structures for hard disk media. However, the spectrum of lubricant is so complicated that it is difficult to assign the peaks. We calculated Raman spectra of the phosphazene-modified perfluoropolyether (A20H) by molecular orbital method. The calculation could assign the spectrum peaks. Every molecule vibration is visually shown so that Raman peaks are identified. We compared the calculated spectrum with the experimental spectrum. Calculated Raman spectrum shows good agreement with that of the experiment.

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To further increase recording density of hard disk drives (HDDs), it is necessary to reduce the flying height of magnetic head. Recently, the flying height of magnetic head is under 2nm by using Dynamic Flying Height (DFH) control. To more reduce the flying height, we studied the light contact recording which means that DFH protrusion is sliding on the lubricant film surface. We analyzed the DFH slider dynamics by acoustic emission (AE) from the PZT element attached on the head suspension. We investigated the effect of lubricant film thickness on the slider dynamics for light contact recording. As a result the lubricant film that thickness is thicker is more suitable for the light contact recording. Specially, it was found that the lubricant thickness should be more than one monolayer.

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Recording media with grooves such as discrete track media (DTM) and bit-patterned media (BPM) are considered to be some of the most promising media for achieving ultrahigh track densities. Thus, it is becoming increasingly important to analyze the static and dynamic characteristics of flying head sliders over DTM/BPM media using the molecular gas-film lubrication (MGL) equation. In this paper, we established an analysis method of van der Waals forces acting between slider and a disk with distribution of material properties by using Fourier series. The characteristics of the van der Waals forces are quantitatively clarified.

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Recently, in hard disk drives(HDDs), slider flying height becomes a few nanometers by using the dynamic flying height (DFH) technology. However, the lubricant pick-up by head slider is increased due to the ultra-low flying height technology. This issue is serius for increasing the drive recording density. It is suggested that the chemically modified air bearing surface will improve the lubricant pick-up. Therefore we evaluated the slider with low surface free energy by chemically modefication.

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To further increase recording density of disk storage drives, thermally-assisted magnetic recording can solve the fundamental issues of thermal fluctuation and is regarded as the key technology for achieving recording density of more than 1 Tb/in^2. In this technology, it is suggested that there is critical issues for the ultra-thin liquid lubricant films and diamond-like carbon (DLC) films on the disk surfaces, because they are heated to high temperature with laser beams. In this study, we focused on the thermal stability of the three types of DLC films deposited by chemical vapor deposition (CVD), ion beam deposition (IBD) and filtered cathodic vacuum arc (FCVA) deposition. We also compared the optical properties of heated three DLC films characterized by ellipsometry, electron spectroscopy for chemical analysis and raman spectroscopy. As a result, the effects of heating temperature on the structure of DLC films were clarified.

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