In the present work, thermal conductivity of lauric acid phase change nanocomposite with carbon based nano-inclusions is measured via transient hot wire method. Two different nanocomposites were prepared: (a) lauric acid embedded with chemically functionalized single walled carbon nanohorns and (b) lauric acid with chemically functionalized graphene nanoplatelets inclusions. On one hand, the addition of graphene nanoplatelets to the phase change material showed a 230% increase in the thermal conductivity of the solid phase for a 1 vol% loading. Such increase in thermal conductivity was not observed either for carbon nanotubes or for metal nanoparticles. On the other hand, carbon nanohorns showed a moderate increase in the thermal conductivity of the solid-phase (37%) and of the liquid-phase (11%) for 2 vol %. In addition the phase change enthalpy of both nanocomposites were measured.

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Time-dependent motion of a concave body in a free-molecular gas under a constant external force is considered using the kinetic theory of gases. As time goes on, the motion approaches a certain steady state with a terminal velocity, where a drag force counterbalances the external force. The drag force for such a time-dependent problem is affected by the motion in the past, i.e., the history of the motion. The manner of the approach to steady motion under the history effect is closely investigated numerically. The concave body is an infinitely long rectangular hollow column with the one of faces taken away. In other words, the body has a square U-shaped cross section. This concavity points toward the direction of the external force. For such a concave body, it is clarified that the history effect results in the slower approach to the terminal velocity compared with that for a convex body.

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We investigated washing effect of nanobubble mixtures on the washing rates of cloth in swirling flow, which was previously reported and used as small scale washing test system. Also, water, surfactant solutions, their fine bubble (nanobubble and microbubble) mixtures were used. The resultant washing effect of surfactant solutions was higher than those of water alone. However, agreement between washing results for water (including surfactant solutions) and their nanobubble mixture ones obtained within the experimental standard deviation. It was opposite result against the previous study using an alternating flow. Moreover, effect of mechanical action was discussed, our discussions were suggested the importance of strong mechanical action in laundry cleaning by using nanobubble mixtures.

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In this study, we measure nonequilibrium ionic responses by developing variable microgap electrodes that enable us to continuously change the electrode distances at a resolution of some tens of nanometers. A relationship between the electrode distance, electrolyte concentration, and ionic response time is comprehensively investigated. In a theoretical model, ion transport phenomena in such narrow spaces are expressed by the effects of electrophoresis, diffusion, and screening. Experimental results measured focusing on the parameters above are mathematically analyzed and the nonequilibrium ion transport occurred in the actual system is in reasonable agreement with the numerical results.

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We analyzed a particle behavior of metal nanoparticles under electric field trapping by directly observing. Electric field trapping is the nanoparticles in the solution is collected toward narrow gap by dielectrophoresis force. We found that the nanoparticles are collected to bridging part, even after the particles are bridged over a narrow gap. Therefore, we fabricated gold wires with a narrow gap and measured diameter of particle cloud corresponding to applied voltage. The diameter of the particle cloud obviously increases as the applied voltage increases. We expect this phenomenon would enable to contribute to additional nanoparticle assembling which is useful for self-healing wire with high healing ability.

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This paper describes an emission spectroscopic method using micro-glow corona to analyze minute volume gases. Glow corona is stable and very small plasma generated at an apex of needle electrode at atmospheric pressure; however, it has never been applied to material decomposition and analysis. To investigate the discharge and spectroscopic characteristics of the glow corona, a sample gas was stepwisely blown toward the micro-glow corona through a glass capillary located in the vicinity of the electrode. We investigated the effect of the gas with various conditions on the discharge current and emission spectra.

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Monte Carlo Brownian Dynamics simulations are used to simulate the properties of polyelectrolyte brushes. For the basic understanding, the effect of linear charge density and surface density of polyelectrolyte brushes is studied. Polyions are grafted to the surface of up to several tens of nanometers pitch. For flexible polyion model of 128 segments, bond and bond angle degree of freedom is adopted. Linear charge density parameter ξ of the polyion is set to 0.5 to 4.0 in order to discuss the Oosawa-Manning's counterion condensation. Thermal equilibrium structure in room temperature of a brush system. When ξ is high, counterions are absorbed in the polyion layer. When the surface density decreases, the height of the brushes slightly increased in high ξ which is not consistent with the scaling theories, but could be understood by Oosawa theory. Net charge distribution showed a potential barrier when ξ is high, which may be related to the electric and kinetic dynamics of the surface.

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The electroosmotic flow pumps which are non-mechanical pumps consisting of a porous material and a pair of electrode have attracted a great interest of many scientists because of their simple structure. In the pumps, movement of counter ions by electrophoresis induces the electroosmotic flow of water within the pores of the porous material. However, generations of gases like hydrogen and oxygen and pH change are caused by electrolysis of water under direct current driving. Recently, alternating current driven electroosmotic flow pump using track etched membrane was proposed by us. From the measurement of zeta potential on the both surface of the membrane, asymmetry of the pump is considered to arise from the asymmetry of the counter ions on the both surfaces of membrane. In this study, rectification mechanism in the pump is proposed through measurement of asymmetry of electric current under alternative current driving, the zeta potentials and the hydrodynamic radius of the pores obtained by the streaming potential measurements.

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We measured gap dependence of dynamic viscoelasticity of hydrated MPC polymer films. The viscoelasticity was evaluated as a damping coefficient c and a spring constant k assuming the Voigt model. As a result of measurement, we observed monotonic increase of c and k as the gap decreased. In addition, from the starting point of these increases we can estimate the hydrated film thickness to be around 3 times thicker than that in the dried condition (before hydration). We also evaluate the loss tangent from the measured c and k and revealed that the elasticity overcame the viscosity when the shearing gap widths were smaller than those equivalent to the film thickness in the dried condition.

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The Synchronized Molecular-Dynamics simulation, which was recently proposed by authors [Phys. Rev. X 4, 041011 (2014)], is applied to the analysis of polymer lubrication between parallel plates. The changes in rheological properties, conformational change of polymer chains, and temperature rise due to the viscous heating are investigated with varying values of thermal conductivity of the polymeric liquid. It is found that with a small applied shear stress on the plate, the temperature of the polymeric liquid only slightly increases in inverse proportion to the thermal conductivity; the apparent viscosity of the polymeric liquid is little affected by changing the thermal conductivity. However, at a large shear stress the transitional behaviors of the polymeric liquid are observed due to the interplay of the shear deformation and viscous heating by changing the thermal conductivity. It is found that this transition is characterized by the Nahme-Griffith number, defined as the ratio of the viscous heating to the thermal conduction.

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Wettability of an isolated Carbon Nanotube (CNT) with various diameter was evaluated by force measurement using atomic force microscope (AFM). In CNT diameter with 4.5 to 10nm, we have found that curvature of CNT affect the solid-liquid surface energy (surface tension). That is to say, wettability of CNT will be different from the flat graphene surface. This finding is in good agreement with the theoretical calculation reported by A. V. Neimark (1999). To the contrary, in CNT diameter under 4.5nm, our results showed apparently different tendency.

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In the present paper, we indicate free molecular t-MGL equation, which is as a function of accommodation coefficients, for examining Thermo-molecular Gas-film Lubrication (t-MGL) characteristics in several nanometers. As the minimum spacing decreases, pressures by the use of conventional t-MGL equation and the free molecular t-MGL equation become close each other, which means free molecular t-MGL equation is applicable for the nanometer region.

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We propose a wearable line-of-sight detection system that utilizes micro-fabricated transparent optical sensors on eyeglasses. These sensors can detect the difference of reflection light intensity between white of eye and pupil. Up until now, we successfully have detected all directions which based on 4 directions (up, down, right, left and), blink by using the proposed system. Our system showed experimentally that the error is as small as 1.5°. In order to develop practical application of our system, we improved our system to detect more precise conditions: open eye, blink, close eye. We finally devised an algorithm which converts these 3 conditions to the input signals.

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This paper describes new interrogation technique of road condition using accelerometer mounted on the commercial driving recorder (DR). Output from the accelerometer is very big data and difficult to evaluate and extract the meaningful information. In this study, big output data was separated to small segments and processed with FFT. After that, each data was evaluated with correlation function analysis. As a result, we confirm that the mapping distribution of correlation function analysis was remarkably related to the smoothness of the load.

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Monitoring of scratching motion, accompany with itchiness, is important for the medical treatment of skin diseases associated with itchiness. In this paper, the microphone sensor system for measuring human scratching by scratch sounds is developed. The dorsal hand microphone is fabricated. And, in order to investigate the relationships between the scratch sounds and the mechanical characteristics of human scratch motion related to the contact force, we measure human scratching motion and scratch sounds by using the developed microphone sensor system and 3 dimensional motion capture system. In experiments, dorsal hand microphone is attached on the back of participates' hand and participates scratch their own skin. From the experimental results, the relationships between skin scratch sounds and contact force during scratching were clarified.

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This paper investigates the output of the wearable skin vibration sensor that authors have developed. The sensor detects skin-propagated vibration. In the experiment, normal and shear vibrations are given to the fingertip and the sensor output and input acceleration are collected to obtain the transfer function of the sensor for each vibration. Result shows that the sensor output is comparatively similar on normal and shear vibrations.

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This research proposes a quantification method for tactile evaluation by hierarchically classify tactile sensations into three groups named low-order of tactile sensation (LTS), high-order of tactile sensation (HTS) and desired tactile sensation (DTS). A sensory evaluation was conducted and factor analysis was performed to extract the common potential factors in each group. Next, multiple regression analysis was used to determine and examine the relationship between LTS-HTS, and HTS-DTS. Then, multiple physical quantities for quantification were measured. After that, the LTS factors were quantified by using the measured physical quantities. As a result, DTS adjectives were also quantified. Lastly, a verification test was conducted and the result showed that the proposed method may possibly evaluate unknown samples' tactile sensation from measured physical quantities.

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In this paper we presents the new possibilities to transfer information using sheet-type electro-tactile displays with micro needle electrodes. This device is designed wearable and can be easily attached to the body. The micro-needle electrodes that penetrates through the stratum corneum allows to give tactile sensation with low power consumption. The fabrication process was developed, then the efficacy of the device was verified by measuring the threshold voltage to give tactile sensation. To figure out the maximum amount of information to be transferred on the forearm through the electro-tactile displays, we conducted the signal distinction test with multiple displays. We attached several displays on the forearm and gave tactile stimulation with each display. We experimentally discovered that we can attach maximum of 6 devices (three devices each on the inside and outside of the forearm).

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In electrophotographic printer, there are several processes of charging, exposure, development, transfer, fusing, and cleaning. As for the quality of printing, tribological factors associated with the rubber roller are important. We focused on the observation of micro-slip occurred between those rollers. However, the width of the contact is wide for commercial microscopes. Thus, we used the laser microscope which has wide field of view by installing low NA objective lens. Many micro contact points were observed and they were created by the small asperities on the rubber surface making contact with cylindrical surface of the smooth glass. Some torque was applied to the rubber roller, and each of the micro contact points slipped individually. The slip distance and the real contact area of each contact points were obtained. Comparing the new and aged rollers, we clarified the difference of micro slip distribution of the rubber roller.

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Surface patterning is effective in improving friction characteristics under lubricating conditions. However, it has hardly to be shown that nanometer-scale patterns can control friction coefficient under oil lubrication. We fabricated three kinds of nanostripe structures having nano-scale grooves that was formed by depositing two kinds of materials on micro-scale slope array and by polishing the surface. Friction tests were carried out by rubbing SiC disk under various load and speed conditions. Friction coefficient was decreased with increase of sliding speed. Zigzag and straight stripes showed lower friction coefficient than discrete stripes. The higher area ratio of nano grooves was, the lower friction coefficient was measured under high load and low speed conditions. I have concluded the improvement in frictional characteristics by performing the nano-pattern.

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We fabricated contoured nanostripe (CNS) surface and examined its friction properties. First, random dents and asperities were formed on stainless steel substrate by shot blast. Next, multilayer films of Ag and Cu were deposited on the substrate, which was then polished to form contoured nanogrooves. Then, the friction properties of the CNS surface were evaluated under a lubricating condition using a ball-on-plate type reciprocating friction tester. An Al_2O_3 ball was used as the counter specimen. After running-in experiment, the relation between the friction coefficient and sliding speed was examined on CNS surface and on Ag or Cu coated surfaces. As the results, CNS surface showed a stable friction coefficient against the sliding distance and showed the lowest friction coefficient compared to other substrates.

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To develop precision mechanical systems, a molecular level understanding of nanometer-thick polar liquid lubricant films under confined shear between two solid surfaces is essential. To obtain such an understanding, we first developed a coarse-grained (CG) molecular model of polar perfluoropolyether (PFPE). This model accurately reproduced distribution functions of molecular structure calculated from all-atom simulations. Using this model, we then conducted molecular dynamics simulations of nanometer-thick polar PFPE films subjected to confined shear between carbon surfaces with random roughness. We found that a short correlation length of the surface roughness prevented solid-liquid interfacial slip and leaded to large shear stress, compared with a long correlation length. Additionally, in the case of the short correlation length, more PFPE molecules formed a polar interaction with the upper solid surface owing to shear-induced molecular motion and orientation, which may increase the risk of lubricant depletion as the upper solid surface is withdrawn.

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This study presented a measurement error for determining the thickness of thin film lubrication based on optical interference methods. The measurement error is caused by the reflective index distribution on the sliding surface, which is characterized by the profile of the surface. In order to demonstrate the measurement error, two types of model specimens with different surface roughness were prepared. Using these specimens, the optical interference measurements of film thickness were performed. As a result, it was found that the reflective index distribution sometimes acts to underestimate the measurement values of the film thickness. The finding of this study provided a new insight for improving the measurement accuracy of thin film measurement using optical interference methods.

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The use of Surface plasmon resonance (SPR) is a powerful method for measuring the properties of thin films adsorbed on solid/solid interfaces. The advantages in using SPR method are its high sensitivity, simple construction, and high time resolution. This study proposed a novel method for in-situ observation of thin boundary lubrication films based on the attenuated total reflection (ATR) in Otto configuration. The developed system was composed of the point contact between a high refractive index prism and a copper hemisphere, and other optical components. From the observation results by the proposed method for interspaces filled up lubricant in contacts, it is found that adsorbed stearic acid film adjacent to real contact areas becomes thicker even if the average interspaces decrease with increasing into contact load, while hexadecane film decreases with increasing into contact load.

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Micro drillings on thin wires are presented to manufacture the micro devices. 0.15 mm drill holes drill holes were machined on the side of 0.3 mm diameter titanium alloy wires with an end mill and a drill. In order to improve the clamping stiffness, the workpiece covered by a urethane tube was clamped on a table with a groove. 0.1 mm blind holes were also machined on the titanium alloy wires with controlling the position and the orientation of machining. The machining error is no more than 7 μm in the operation. The presented drilling is effective in the micro machining on thin wire in applicable cutting conditions.

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This paper reports the 3D vessel model having temperature history indicator for surgical simulator. The temperature indicator consists of polydimethylsiloxane (PDMS) and thermochromic pigment presenting non-reversible color change according to temperature increase. The indicator has transparency to observe the catheter inside the model during simulation. Distribution of maximum increased temperature is calculated from the color change of the indicator using image analysis. In the range of the indicator is from 50 to 94 degree of C, the accuracy of the temperature measurement is approximately 2.0 degrees of C. The renal artery model having temperature sensor was fabricated by rapid prototyping of wax mold, dip-coating of temperature indicator, and remove of was mold.

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In this study, we propose a novel method named "3D block printing" to make a 3D object with different materials. This system allows us to produce arbitrary shaped 3D models by assembling multiple blocks of different materials. For medical application, bioceramic blocks for constructing 3D scaffolds were made with β-tricalciumphosphate (β-TCP) slurry. As a method to produce bioceramic blocks, we used a soft-molding process based on stereolithography and ceramic molding. Sintering condition was optimized to remove dispersant mixed into the slurry completely. Both dispersion and shrinkage ratio of bioceramic blocks during soft-molding process were examined. As a result, it was found that the average dispersion and shrinkage ratio of sintered ceramic blocks are about 12 μm and 18%, respectively. Finally, we succeeded in fabricating a 3D scaffold by constructing several blocks.

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We have developed a novel micro stereolithography system that can provide scalable resolutions by using multiple optical fibers. Four kinds of optical fibers with different core diameters were used in experiments. The use of optical fibers from mode field diameter (2.4 μm) to core diameter (200 μm) allows us to obtain the resolution ranging from 1 to 150 μm. From these results, we have verified that the micro stereolithography system using multiple optical fibers can adjust the resolution by changing the optical fibers. Additionally, we have succeeded in controlling the hardened depth by mixing ultraviolet absorber into the photopolymer. A cantilever structure (thickness: 17 μm) was successfully fabricated. The scalable micro stereolithography system will be useful for making large-scale three-dimensional structures containing complex microstructures in a short time.

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Mechanically deformable devices and sensors enable conformal coverage of electronic systems on curved and soft surfaces. Sensors utilizing liquids confined in soft templates as the sensing component present the ideal platform for such applications, as liquids are inherently more deformable than solids. However, to date, liquid-based devices have been limited to metal lines based on a single liquid component given the difficulty in the fabrication and system integration. Here we demonstrate a platform for the fabrication of liquid-liquid "heterojunction" devices and liquid-state system, presenting an important advancement for expanding liquid electronics. The device architecture and fabrication scheme we present are generic for different sensing liquids, enabling demonstration of sensors responsive to different stimuli. As a proof of concept, we demonstrate temperature, humidity and oxygen sensors by using different ionic liquids, exhibiting high sensitivity with excellent mechanical deformability arising from the inherent property of the liquid phase.

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This paper reports on a bicone-shaped micro coil for magnetic resonance imaging (MRI) which has low resistance and low parasitic capacitance. The micro coil was fabricated by vacuum evaporation and electroplating of Cu onto the stepped helical structures made by 3D printer. Since the helical structure was fixed on the rotary-tilted stage, Cu was evaporated only the wiring part of the helical structure. Furthermore, we could reduce the resistance by electroplating and by increase the linewidth of wiring made by 3D printer. Therefore we took high SNR (Signal to Noise Ratio) MRI images by the fabricated bicone-shaped coil.

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A part of kinetic heartbeat signal will transmit to lung mechanics, because they are contacted to each other. It means that it might be overlapped to breathing signals, and output as the airflow at the mouth. Thus, we challenged to detect both heartbeat and respiration kinetic signals from the airflow at the mouth. A rat under heavy anesthetic condition was experimentally used to confirm the above phenomenon, and a catheter flow sensor with outer diameter of 1.8 mm was fabricated by MEMS technologies. An electrocardiogram (ECG) was also used as a standard of heartbeat detection. The flow sensor was inserted into a rat's airway, and the airflow dominated mostly by lung breathings was measured. The heartbeat signals caused by physical heart movement was extracted from the airflow waveform by analyzing it with discrete Fourier transform, and its frequency was confirmed to coincident to electrical signal frequency obtained in ECG. We finally concluded that we can simultaneously measure both heartbeat and respiration kinetic functions from the airflow at the mouth.

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In this paper, we propose a candle-like micro-needle electrode for electroencephalogram (EEG) measurement from the hairy part of the scalp. Conventional wet electrodes for EEG measurement require skin abrasion and electrically conductive gel. This is time-consuming and uncomfortable. On the other hand, micro-needle electrodes can eliminate this process by penetrating through the high impedance stratum corneum. So far, our group has developed a polymer-based dry micro-needle electrode and measured EEG from the frontal pole. However, it was impossible to measure EEG from the hairy part of the scalp by using this electrode because hair obstructs contact between microneedles and the scalp. Therefore, we fabricated candle-like micro-needle electrodes that has pillars for avoiding hair and measured EEG from the occipital, where there is hair. The acquired signal showed as high quality as the conventional wet electrode.

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We proposed two different types microneedles, a two-layers and a tip-separable microneedles, to improve the quantitative of the dosage in drug delivery systems based on the microneedle devices. The medicine is included in a part of needle tip region in the former microneedle. On the other hand, the latter microneedle device is composed of a sharp tip containing medicine and a supporting base. The tips penetrated into the skin surface are separated and placed in the skin inside by removing the supporting base. At first, pyramidal shaped Si microneedles were fabricated by applying a photolithography and anisotropic wet etching of KOH. Then, both microneedles were successfully fabricated using the molding process.

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This paper presents development of water-permeable dialysis membranes that are suitable for the implantable micro dialysis system that does not use the dialysis fluid. We developed micro dialysis system integrating microfluidic channels and nanoporous filtering membranes made of polyethersulfone (PES), aiming at a fully implantable system that drastically improves the quality-of-life of patients. We conducted in vivo experiments using rats, where the system was connected to the femoral artery and jugular vein. The filtrate was successfully collected without any leakage of blood inside the system. The rat model with renal failure showed 100% increase of creatinine in 5 h while the rat connected with the system showed only 7.4% of increase, which verified the effectiveness of the proposed micro dialysis system.

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Observation of illness and disease in vitro allows us to efficiently investigate the cellular mechanism. We have developed a massively parallel cell assembly technology using a dielectrophoretic probe array. In this paper, to assist massively parallel cell assembly, we develop an open-top cell feeder and perform the evaluation of cell capture. An open-top cell feeder is made of a transparent electrode and a PDMS chamber, where cells are stored. A delectrophoretic probe array can access to the cell feeder. We fabricated an open-top cell feeder and collected HeLa cells around electrodes. Long-distance cells did not migrate by dielectrophoretic force.

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This paper presents capturing technique of the circulating tumor cells (CTCs)using a nucleic acid aptamer. A nucleic acid aptamer that is able to specifically bind with epithelial cell adhesion molecule (EpCAM) was used for capturing the CTCs. The specific adsorption test of a nucleic acid aptamer and cancer cell (MDA-MB-453) was carried out for verification of principle by fluorescently-labeled aptamer and fluorescently-labeled scrambled DNA. As results, the nucleic acid aptamer bind with MDA-MB-453, and the scrambled DNA did not bind with MDA-MB-453. Also, CTC capturing test was carried out using a fabricated nucleic acid aptamer-modified device. In the result of the evaluation, MDA-MB-453 was successfully captured by the nucleic acid aptamer modified on the substrate, and adsorption of healthy cell (HEK-293T) was successfully inhibited.

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In this paper, we present a design approach for electrostatic energy harvester under low acceleration. In electrostatic energy harvester, the electrostatic force that prevents mass movement or causes pull-in is occurred due to the charged electret. We propose a dual-phase electrode arrangement and bipolar charged electret to reduce the electrostatic force. Utilizing dual-phase electrode arrangement or bipolar charged electret, the electrostatic energy harvester can reduce electrostatic force both vertical and horizon directions in a static condition from FEM analysis. It is found that the approached electrostatic energy harvester can generate more power than conventional structure in a low acceleration from SPICE equivalent circuit model. In addition, the air-gap can be smaller and the limited output power can be higher by reducing vertical electrostatic force.

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In this study, we controlled tilted angle or AlN c-axis in the aim of high performance AlN-based energy harvester (VEHs). Tilt-angle of the c-axis of the AlN thin films was adjusted by changing growth temperature from 420℃ to 650℃. The results were confirm by X-ray diffractromety equipped with two dimensional detector (2D-XRD). At 420℃ the c-axis tilted 22°, which is the largest tilt angle reported for the AlN films grown by incident angle deposition. In addition, by changing growth temperature, we succeeded in preparing c-axis tilted AlN films with different tilt angle. Scanning electron spectroscopy (SEM) revealed that the c-axis tilted films have tilted columnar structures which prevents cracks and pinholes going straight through the films. This feature may help avoiding electrical short between electrodes fabricated on top and bottom of the AlN films in VEHs.

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This paper reports that a charging mechanism of the electret film made of Potassium ion-doped SiO_2 film. First, we obtained an experimental result that the charging is only occurred in positively biased electrode but not occurred in negatively side process and its charging polarity is negative. Following the result, we supposed that the origin of the charging in the electret film is oxygen defect in the SiO_2 which arises as a result of Potassium ions moving. In order to ensure the reliability of the charging mechanism, three different samples were analyzed with Secondary Ion Mass Spectrometry. First sample is positively biased electrode, Second sample is negatively biased electrode and Third sample is not done anything. From the result, Potassium ion concentration with respect to depth and charging voltage was indicated.

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This paper reports the development of MEMS rotational electret energy harvester (EH) for human motion. Optimal design of MEMS EH is proposed by considering both the rate of overlapping-area-change and the parasitic capacitance. Number of poles is optimized with the present design method. A rotational MEMS EH with embedded ball bearing has been successfully developed. Up to 3.6 μW has been obtained at 1 rps rotation with an early prototype.

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This paper reports a plate-type thermoelectric power generator (TPG) having bi-metal interface which convert heat into electricity. The size of the TPG is 20 × 30 mm^2, and that of the bi-metal interface is 20 × 5 mm^2. A part of the Al surface for the bi-metal interface side was heated and the thermoelectromotive force due to the temperature gradient in the TPG was measured. The TPG having the oxidized bi-metal interface showed higher thermoelectromotive force compared with the TPG without oxidation. The Seebeck coefficient of the TPG having the oxidized bi-metal interface was measured to be about 8.1 μV/K.

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We report for the first time thermal conduction tuning in phononic crystals. This tuning is based on the wave properties of phonons at low temperature, similarly to what can be done with photons.

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A thin-film thermoelectric generator with anti-reflection structures was fabricated to convert near-infrared solar light, which cannot be converted to electric energy by photovoltaic conversion, to electric energy. The anti-reflection structures were designed using Rigorous Coupled Wave Analysis, resulting that the anti-reflection structures which were formed by close-packed SiO_2 microspheres with 200 nm diameter and coated with CuO thin films estimated to be 6.7%. The anti-reflection structures were formed onto the SiO_2 glass substrate by dip coating method. When the SiO_2 microspheres were dispersed into deionized water and amphiphilic block copolymer F-127, the hexagonally close-packed microspheres were formed on the substrate by dip coating. Bi_<0.5>Sb_<1.5>Te_3 (p-type) and Bi_2Te_<2.7>Se_<0.3> (n-type) thin film elements were formed onto the glass substrate by lithography and sputtering method and serially connected by Cu thin films. After SiO_2 thin-film over-coating the thermoelectric elements, CuO-based anti-reflection structures were successfully formed onto the hot side of the generators.

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In order to extension application of printing thermoelectric (TE) technology, we developed "TE inks". However, the TE devices made from the TE ink did not show good performance, because the density of printed device was not enough compared to commercial TE devices. In this study, we investigate the effect of hot-press conditions on the thermoelectric performance of the TE devices made from the TE inks. As increasing the hot-press temperature, ZT increases and shows a maximum around T_<HP>=723 K. On the other hand, the hot-press pressure P_<HP> is not effective. It should be noted that the drying-process plays the most important role of improvement of device performance and increasing of ZT.

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We examine a cryoprotectant-free cell cryopreservation method using an inkjet cell printing. When cells are frozen in normal culture medium by slow-rate freezing, ice crystals generate inside and outside the cell. Cell structures including cell membrane and subcellular organelle are destroyed by the ice crystals. As the cooling rate become fast, the generation and growth of ice crystals are inhibited. We used inkjet technique and liquid nitrogen to freeze picolitter droplets at an ultrahigh cooling rate. We performed heat transfer simulation of flash freezing. The simulation result showed that the cooling rate in our method was much faster than in the previous studies. Moreover, we represented that the cell viability in flash freezing was much higher than in the previous studies. This result indicates that the cell viability is improved by increasing the cooling rate.

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The object of this work is to evaluate mechanical properties of cells based on the deformation behavior of cells. In this method, a cell compression microdevice is used to apply pressure to cells. This microdevice is designed to control the magnitude of pressure to cells and to observe deformation behavior of cells in a real time. The fabricated microdevice is assembled by stacking two layers of self-adhesive polydimethylsiloxane structures on the glass plate. The first layer consists of microchannels, cell culture chambers, and a diaphragm on the culture chamber for applying pressure to cells, and the second layer consists of cell inlet ports, a pressure port, and a gasket. The Young's modulus of cells was determined based on the behavior of compressed cell. Also, we verified the presented method can be used as a new tool for evaluating cell mechanical properties.

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We propose a novel nanofabrication technique for Si based on highly localized chemical catalysis with a platinum-coated AFM tip. Nanoscale grooves can be fabricated on a Si surface at room temperature via Pt-assisted catalytic chemical etching in just water without adding any chemicals to be used as an etchant for Si. In the process, we found that dissolved oxygen present in the water must be a key element to drive the chemical reaction of Si with water. Moreover, experimental results suggested that the oscillating cantilever, i.e. the stirring of the water must be required to overcome oxygen mass transfer limitations, thus enhancing the etch rate. According to electrochemical theory, the elementary chemical reactions during the etching of Si can be estimated as follows. In the first step, the dissolved oxygen (O_2) is reduced and forms hydroxide ions (OH^-) with the water on the surface of the Pt-coated AFM probe. In the second step, the oxidation of Si atoms by the OH^- ions occurs, thus forming a water-soluble silicate (SiO_2(OH)_2^<2->).

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Micro-temperature sensors consisting of Cu_2O-rich sensing part and Cu-rich electrodes were fabricated using femtosecond laser induced reduction of CuO nanoparticles. Cu_2O-rich and Cu-rich microstructures were selectively formed by controlling laser irradiation conditions. When the laser scanning pitch was 10 μm, Cu_2O-rich microstructures were formed under the condition that the laser scanning speed and pulse energy were 1 mm/s and 0.45 nJ, respectively. Cu-rich microstructures were fabricated by the scanning speed of 10 mm/s and the pulse energy of 0.28 nJ. The Cu_2O-rich sensing part and Cu-rich electrodes were formed using the evaluated conditions. The micro-temperature sensors composed of Cu_2O-rich and Cu-rich hybrid structures were successfully obtained.

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We measured out-of-plane and in-plane deformations of beams in order to design beam shape which can deform out-of-plane or in-plane on a same substrate for multi-axis thermal actuator using single layer. We used buckling for deformation of beams, because buckling can change the direction between input and output deformations. Direction of deformation of beams can be changed by shape of beams. Therefor we measure deformation of curved beams with initial deflection. We fabricated and measured out-of-plane and in-plane deformations of the curved beams with 1000 μm in length, 20 μm in width, 5 μm in thickness and an initial deflection. As a result, curved beams with 0, 10, 100 μm in initial deflection deformed only in out-of-plane direction, in both out-of-plane and in-plane directions, and only in in-plane direction, respectively. This result shows we can control direction of deformation by designing initial deflection.

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Proton exchange membrane fuel cells (PEMFCs) are promising systems for mobile and vehicle applications because of their high power density and low operating temperature. This characteristic causes the several problems, such as water management. Then for measuring the local humidity inside membrane electrode assembly (MEA), the thin film humidity sensors are fabricated by the micro-electro-mechanical systems (MEMS) based techniques. The sensor was placed between the catalyst layer (CL) and the microporous layer (MPL) at the cathode. The slight effects on total cell performance were observed with the insertion of it. In-situ measurement with a humidity sensor showed the capacitance and RH increased with the increase of the current density linearly up to 0.3 A/cm^2. The capacitance change became moderate in the region of current density 0.3 A/cm^2, because the relative humidity reached 100% at the 0.3 A/cm^2 and water started to accumulate.

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