Data storage related with writing and retrieving requires high storage capacity, fast transfer rate and shorter access time. Today there are no data storage systems which can satisfy these conditions, however a holographic data storage system can perform. A faster data transfer rate because it is a paper oriented memory system using a volume hologram in writing and retrieving data. Moreover, Holographic data storage system need title and servo control stably. We propose noise reduction by Extended Kalman Filter(EKF) method to tilt servo control in holographic data storage system. Firstly, introduce our holographic data storage system, and then, explain Extened Kalman Filter(EFK) in holographic data storage system, and then, you can see simulations and experiments, finally, explain conclusions in our holographic data storage system.

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Cover thickness influence to the vibration of multilayer ceramic capacitor was analyzed in this study. The results can be helpfully taken to the capacitor design for vibration reduction. 3-D detailed simulation model based on the finite element method was constructed for parametric study and it was verified through the vibration tests. Parametric study with respect to the cover thickness shows that thickening the L cover and W cover increase the vibration amplitude of top surface and decrease the head and side surface. On the other hand, T cover was not related to the vibration amplitude of MLCC.

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Solid State Drive (SSD) is based on Nand flash memory, so it has almost no factor for structure-borne noise as there is no mechanically moving parts. However, high-pitched noise from SSD has become a special issue raised from many users. Vibration tests were performed in this study to investigate the main cause of high-pitched noise from the SSD. Natural frequencies and its corresponding mode shapes were tested by modal testing. Also, sound pressure at certain points were measured when SSD is on reading and writing condition. The natural frequencies from both experiments were matched, which means the vibration of circuit board is main factor for high-pitched noise.

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We investigate the characteristics of cogging torque and unbalanced magnetic force (UMF) due to the interaction between magnetization of permanent magnet (PM) and stator eccentricity in PM motors. We numerically show that the third harmonic of PM magnetization interacts with stator eccentricity to decrease the amplitude of pole harmonic of the cogging torque and UMF as well as to increase the amplitude of the least common multiple harmonic of pole and slot numbers in the PM motors. We experimentally verify the effect of the third harmonic of PM magnetization on UMF and acoustic noise in the PM motors with stator eccentricity.

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Aerodynamic pressure pulsation generated by rotating fan blades was measured using a basic experimental device consisting of fan blades, a motor, and pressure gauges. The motor was installed on a high-stiffness block via load cells and the motor reaction forces were measured by load cells. On the other hand the aerodynamic pressure pulsation was also calculated using CFD simulation software, and based on those CFD results, motor reaction forces were also derived. Calculation results and experimental results were compared for both pressure pulsation and motor reaction forces. Finally, calculations were found to agree well with experimental results.

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Flow fields in 2-blade and 4-blade half-ducted propeller fans for the outdoor units of air-conditioners were calculated with finite element method-based large eddy simulation (LES) with the aim of investigating what influence of blade number had on aerodynamic noise in this study. The aerodynamic noise of 2-blade propeller fan was smaller than that of the 4-blade by 5.9dB experimentally at an operating flow coefficient. As a result, we confirmed that the tip vortex (TV) had a great influence on half-ducted propeller fans. The TV trajectory and the blade pitch of the 2-blade propeller fan were longer than those of the 4-blade propeller fan. These suppressed the interaction between the TV and the adjacent blade, because the vorticity of the 2-blade propeller fan decayed along with the TV than that of the 4-blade propeller fan, and the minimum distance between TV and the adjacent blade of the 2-blade propeller fan was four times longer than that of the 4-blade propeller fan. The 2-blade propeller fan was therefore more silent than the 4-blade propeller fan.

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In this paper, we report a measurement method of viscoelastic properties of the grasped objects using a grasping forceps with sensors. Stiffness is one of the important information to distinguish the cancerous tissue from normal tissues because the mechanical properties of cancerous tissue change according to the grade of cancer. However, in laparoscopic surgery, it is difficult to acquire the tactile information including the stiffness. Thus, we have proposed a measurement method of stiffness by the special instrument used for the laparoscopic surgery to support surgeons. However, the viscoelasticity is not considered in the preceding method though organs are viscoelastic materials. We have already observed the stress relaxation, which is a viscoelastic phenomenon, using the grasping forceps with sensors. In this paper, we evaluated the viscoelasticity of the grasped object by measuring the stress relaxation and compared the viscoelastic properties acquired by the grasping forceps to those acquired by the conventional compression test. The grasped objects were expressed as viscoelastic materials with 3-element Maxwell model. The viscoelastic parameters, E_∞, E_1, and η_1, were calculated by fitting the theoretical curve using least squares approximation to the time response of the stress during the stress relaxation. The values of the viscoelastic parameters of 30% gelatin acquired by viscoelasticity measurement with forceps were E_∞ = 32 ± 5 kPa, E_1 = 13 ± 3 kPa, η_1 = 0.77 ± 0.41 MPa・s. Though E_∞ and E_1 were smaller than those acquired by the conventional compression test, the stress relaxation was observed and the relaxation time τ_1 was similar to that of the conventional compression test.

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Surgeons use a low velocity for the palpation in open surgery. Considering the slow palpation movement, a sensor substituting surgeons' tactile sense might require to detect temporal and spatial distribution of contact force. In this study, we improved our previous sensor using acoustic reflection, remaining the overall dimension of the previous sensor. Theoretical and experimental results show that the improved sensor is capable of detecting both the contact position and force.

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In this paper, palpation motions for prostate gland were measured using prostate examination simulator and motion capture system in order to evaluate the motion. In the measurements, six prostate models were prepared as palpation samples. While subjects diagnose the presence of lumps in prostate models and the size of prostate, fingertip position and force applying on prostate models were measured. From the results, it was confirmed that the expert diagnosed the state of prostate glands more accurately. By comparison of motion characteristics between the expert and beginners, the motion characteristics of experts were extracted.

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In this paper, usability evaluation of a compact Braille reading sensor was carried out. Several sensors with different grips and guide components were fabricated. Using these sensors, sensory evaluation related to usability was conducted. At the same time, self- straitening characteristics of the sensors were evaluated by motion analysis. From the results, it was found that guide part with the groove width spreading toward the front of the sensor is effective for a usable sensor with high self-straightening characteristics, and it was suggested that the grip part should be designed to suit the preference of the user.

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The HIT lower limb exoskeleton is presented for load-carrying augmentation of human being. The load-supporting stages during a gait cycle mainly include the single support phase and the double support phase. And the latter gradually disappears with the increase of the walking speed. In this paper, we focused on the human movement detection and exoskeleton control in the single support phase. The HIT lower limb exoskeleton is only actuated on the hip and knee. A dorsal man- machine interaction device is designed and installed between the human back and the exoskeleton to detect the interaction forces, including two-dimensional forces and one-dimensional torque on the sagittal plane. By the kinematic analysis, an equivalent kinematics model is establishment. Then all the control objectives are described in the new coordinate systems of the equivalent model. As an underactuated system, not all the dorsal interaction forces could be relieved. Based on the selected control inputs, a double feedback control strategy is designed for the supporting leg control.

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This study presents a novel approach of measuring quantity of melanin skin in a noninvasive way using Photoplethysmography (PPG). PPG sensors are widely used in noninvasive diagnosis and highly related to human skin and cardiovascular system health. In this study, a low power, low noise circuit which is able to evaluate skin melanin content and blood pressure simultaneously is successfully designed. The whole system is implemented as a system on chip (SOC) and fabricated by TSMC 0.18μm integrated circuit process. The performance of circuit is low power consumptions and high measurement accuracy. The error between simulation and measurement result is less than 3% while power consumption is as low as 1.5 mW.

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In this study, the complete 3D wrist multi-physics finite element model (FEM) model was built to predict the vibration of radial artery and the BP, diastolic blood pressures (DBP) and systolic blood pressures (SBP). This model includes physics from several different fields including fluid mechanics, structural mechanics, electric currents and electric circuit coupled. In this study, a novel simulation method was used in non-invasive, cuffless BP sensor via a 3D fluid-solid-electric FEM which includes sensor of gel capsule and strain-sensing electrodes, radial artery, blood, radius bones, tendon, muscles and the front-end readout circuit. The experiment was established to validate the results with 3D wrist FEM model. As experiment and simulation results, the errors of strain variation are under 10 percent and around 30 percent by using fluid-solid-electric FEM and fluid-solid FEM, respectively. A novel simulation method in non-invasive, cuffless BP sensor was successfully developed via a 3D fluid-solid-electric FEM. The simulation results of strain variation are close to the experiments results, thus the 3D fluid-solid-electric FEM model in this study was effective and superior. A new 3D fluid-solid- electric coupling interaction finite element model of the wrist is built for predicting the vibration of radial artery and then diastolic and systolic blood pressures.

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A method for quantitative assessment for patellar tendon reflex was described. Considering kinematic features of the PTR, integrated portable equipment was developed utilizing a multi-axes inertial sensor, a tap force sensor, and an EMG sensor. Relationships between tap forces and kicking movements of lower leg were evaluated for identifying a nature of patellar tendon reflex, which was expressed by an exponential function and delay parameters. The results demonstrated that the method quantifies reflex intensities and latencies reasonably, which is not easily characterized by the conventional scale, and potentially useful for assessing PTR in daily practice with the effortless handy device.

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Photodynamic therapy (PDT), which is able to destroy tiny lesions to minimize tumor recurrence and also remove target tumor part very precisely, has been extensively investigated. There are two main endoscope techniques at present, laser fiber separated from endoscope and endoscopic palliative techniques. However, the use of former method renders larger operative incision, and the latter endoscope provides a view field which is different from the laser irradiation field. To solve the problem, in this paper, we propose a novel flexible coaxial laser endoscope system for PDT, which is able to provide image and transmit laser to object target simultaneously. In this system, a flexible imaging fiber bundle is applied for its coherent light guiding. The visible light is transmitted into flexible imaging fiber bundle, reflected by polarizing beam splitter, then camera catches the image. And at the same time diode laser for PDT passes through the beam splitter into imaging fiber bundle. After traversing fiber bundle, the laser irradiates object target. In the experience, we give the results to evaluate the endoscope image, and also measure the laser power loss from laser fiber to endoscope header.

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We've been developing a small and light robot for oral and maxillofacial surgery. This robot has a novel positioning mechanism, and it isn't well-known yet how the error of this mechanism occurs. In this paper, we analyzed how much effect the backlashes and installation error had on the error of the endpoint, and simulated the trajectory of the motion for positioning. As a result of the comparison between the actual position and simulated, the RMS was 0.51 [mm]. For validating this simulation the positioning accuracy was measured with the offset control in order to cancel errors. The accuracy was improved: from 1.06[mm] to 0.65[mm] (RMS). This knowledge account for selecting the suitable tolerance class of the mechanical components.

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Current significant focuses of Hard Disk Drive (HDD) research and development are the next generation of recording technology and responding to the economic pressure from flash or solid state storage technology. The market share for flash storage has been gradually increasing for years in both high performance and mobile applications. Among the strongest factors for choosing HDDs are cost in $/TB and energy density in W/m 3 . Developers and researchers in solid state storage are working to improve in these areas as well. Common to future recording technologies (HAMR, MAMR, TDMR or BPM) is the consequently larger increase in radial density than linear density. In other words, the TPI will increase more significantly than BPI and the servomechanical design must improve dramatically to support future products. Traditional evolutionary approaches of internal disturbance reduction and controller enhancement will fall short when it comes to meeting the 1 MTPI challenge, largely because external disturbances are not under design control so they cannot be reduced to scale with track pitch. To reach 1 MTPI, HDDs will need evolutionary changes and will increasingly rely on other active elements such as sensors and controller stages to enhance the effective bandwidth of the control system. More effective use of sensors (new or current sensors) requires improvements in either SNR, or the correlation between signals and offtrack motion. Their usage is complicated because the market is sensitive to the cost per TB, and the cost per HDD. New recording technologies will add to HDD cost so using more and/or more complex sensors carries economic risk unless they can be added with minimal cost. As always with HDDs, the fundamental challenge remains: to improve performance within the current range of production cost.

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Printed electronics (PE) has been emerged as one of the key manufacturing processes for a wide variety of electronics products not only for home appliances but also for vehicles and for business-scale. The advances of nanomaterials, especially metallic and organic conductive materials, for PE brought printed electronics into the reality. Sensing components by using metallic nanowires enable us to replace the conventional ITO transparent electrode to affordable, flexible, bendable, and even stretchable touch sensors. Wearable devices are another hot topic of PE in the field of sports and fitness to healthcare. For wearable devices, not only wiring with metallic/organic materials, sensing, wireless transmission, and energy harvesting components must be equipped into a thin and flexible substrate with a suitable barrier structure. This presentation will provide the current status of various nanomaterials for PE.

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Intelligent sensors that not only detects the distances to obstacles, but acquires other relevant information, such as the position and motion of other cars and pedestrians should be used for the collision avoidance system. Stereo vision is suitable for this application. I will present obstacle detection technique using the stereo vision system and applications to detect pedestrian running out into the road.

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This paper provides an interaction science and noninvasive brain function measurement using NIRS to examine brain activity during vibration. In the paper, the comfort level is evaluated using the sensory evaluation as the subjective evaluation of vibration, and the brain activities are evaluated using NIRS for objective evaluation. Based on the analysis of brain-activity during the sensation of vibration, the relationship between vibrations, comfortableness of a ride and brain activity will be considered.

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In this paper, a relationship of a natural frequency, a damping and a feedforward acceleration with a transient vibration of track-seek control was derived theoretically, and a proper design target for dynamics of a head actuator of a hard drive was discussed from the viewpoint of reducing the transient vibrations. When the feedforward acceleration of the track-seek control is expressed as a polynomial, a transient response of a single degree-of-freedom (DOF) system is solved by applying integral by parts to the Duhamel's integral. The results shows the transient vibrations are generated at the initial and terminal of the feedforward acceleration and its amplitude depends on the orders of non-zero derivatives of the polynomial. Meanwhile, the amplitude also depends on seek time and it should be reduced as decreasing track pitch. The seek time and track pitch are key factors related to drive performances: access time and capacity. So, the target of the transient vibration reduction also depends on the order of polynomial.

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This work reports the measurement results on a mock-up chassis that has the same structure as the center column of a real chassis to be developed. The reported results include the measurement data of throughput of each disk drive in the mock-up chassis, the temperature distribution in the mock-up chassis and the measured vibration level of the chassis as well as the reliability test of the chassis. Some critical factors that affect the throughput performance will be addressed and discussed. The suggestions to improve the chassis design will be mentioned based on our observations during the mock-up chassis testing and measurement.

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The positioning performance of VCM and PZT dual stage controller in commercial HDDs is studied. The key issue is the PZT nonlinear characteristics, like a saturation. We calculate the nonlinear effects when large disturbance acts on. The results show the nonlinearity degrades the positioning accuracy and the limitation of the dual stage feedback controller. They also show the effectiveness of the feedforward compensator.

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Hard disk drives are packed with increasingly higher density in modern data storage enclosures and systems. This may impose some risks to the system dynamic performances if the system is not well designed. For example, the hard disk drive (HDD) read and write (R/W) performance will be degraded more due to higher mechanical cross-talk as there are more and closely arranged HDDs in the system. Secondary, the more HDDs packed in a storage enclosure, the more mass the system has. This lowers the system modal frequencies and likely affects its dynamic performances, such as non-operational shock behavior during shipping and handling of the system and HDD operational vibration due to external vibrations. In this paper, we will study both non-operational shock and operational vibration using a state of the art HGST storage enclosure which has the highest HDD volumetric density packaged in any enclosure on the market.

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In this study, simplified numerical analysis and experimental study were conducted for operational shock of Hard Disk Drive (HDD). In the numerical analysis, we calculated flying attitude of slider under shock condition by using Molecular Gass-film Lubrication (MGL) equation. In the experiment, dynamic capacitance was measured to detect contact between slider and disk during shock event. The analysis results showed same trend as the experimental results. These results showed that the slider-disk contact occurs by suspension load loss and slider moment change during operational shock.

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The authors have executed a fundamental design of a sliding system for probe-based memories, next-generation storage devices specifically for the data archiving application. According to the results of an experiment using ferroelectric recording media and an antiwear probe, the proposed system endured a meter-scale probe slide without any readout resolution degradation of recorded patterns.

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A highly precise positionning actuator for a Scanning Prove Microscopes (SPM) and a magnetic recording evaluation system was developed. The positionning actuator was consisted of a displacement amplitude mechanism and a stacked piezoelectric element (PE). In this paper, we propose a new X-Y plane positioning actuator composed of two pair of tracking actuator, parallel link with square support spring and positioning stage we mesured. The control performance and the plane positioning accuracy to be verified. Furthermore, the influence of the tracking actuator on the transient response and the out of plane moment of the PE precise positioning stage has be discussed.

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We have developed a novel experimental setup that enabled us to observe an actual contact area at the nano-scale. The observation of actual contact area in real-time is significant step toward understanding the origin of friction and the mechanisms of lubrication. Therefore, we believe that our results can provide the insight of friction phenomena.

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A method, which analyses the dynamic characteristics of slider air-bearing for hard disk drives, is introduced. A perturbation algorithm, which is free from problems caused by nonlinear forces in the near-contact region, is adopted. A procedure for obtaining the modal parameters, such as modal frequencies and modal damping ratios, is presented. A femt slider used as an example is analyzed, and the results are examined to confirm the method's applicability. The dynamic performance of air-bearing for the near-contact flying height is evaluated and the effect of interfacial force is clarified.

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The nano-scale active air-bearing slider dynamics has been widely investigated for stability and reliability improvement. However, the uncertainty quantification has been lacking. This paper highlights the nonlinear stochastic dynamics perspectives on the instability of TFC sliders during the touch-down process. A nonlinear stochastic dynamics model is developed to quantitatively study instability of TFC sliders at the near contact regime and to explain the nonlinear stochastic dynamic behaviors of TFC sliders at the touch-down process. The simulation results reveal the extent of uncertainty.

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This paper presents a method to measure instantaneous Fly Height (FH) motion and cross track motion concurrently by using read back signal of dual data tracks written with different frequency. For a specific air bearing surface design (ABS), it validate the method is robust to separate the FH motion and cross track motion in the measurement.

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To increase the recording density of magnetic disk drives, the reduction of spacing between the flying slider and the rotating disk is of great importance. When the spacing between the slider and the disk approximates the molecular mean-free path, intermittent contacts between slider and disk are more likely to occur. One critical challenge for modern magnetic disk drive is the ability to achieve stable and small spacing between the read/write head and data storage media. In this paper, we describe an experiment to identify the factors contributing to the dynamics stability and present the experimental results. Two types of slider design are selected to investigate the ambient pressure effect on touch-down and take-off of air bearing slider in the head/disk interface.

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To understand why barium ferrite (BaFe) tape exhibits low friction and small spacing loss, the magnetic spacing, transition parameter and head/tape physical spacing were investigated and compared with metal particle (MP) tape. As a result, we found that using BaFe tape can reduce both the magnetic spacing and the transition parameter while maintaining a similar friction (physical spacing) as that of MP tape. The ability to reduce these parameters is considered to be due to a particle property specific to barium ferrite. These results suggest that BaFe tape is superior to MP tape for high-density recording.

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PDMS (polydimethylsiloxane) can be generated from cyclic oligomers such as D4, cyclotetra(dimethylsiloxane), by the ring opening polymerization process. The reaction is reversible and is catalyzed by a proton or an alkaline ion in either direction. The catalyst ions may remain trapped in the product polymer. Thus on warming, depolymerization could occur leading to emanation of the vapor of cyclic oligomers. The intramolecular disproportionation reaction of PFPE (perfluoropolyether) catalyzed by a Lewis acid center (e.g. those formed on nascent aluminum oxide surface) generates fragments possessing an acylfluoride end group, R-C(=O)F which readily converts to the acid form, R-C(=O)OH. It is postulated that the siloxane smear observed on disk surface is due to that generated by repolymerization of the oligomer (emanated from PDMS containing parts) catalyzed by the acid resulting from the PFPE lubricant degradation.

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Magnetic head wear performance was studied usingvarious kinds of D-4OH lubricant thickness of hard disk(HD) media. Different characteristic behavior wasobserved in each lubricant thickness. The difference ofthe behavior was well related with media frictioncoefficiency. At the same time, surface free energychanged as well as it. According to lubricant coverageanalysis, it was found that the head wear behaviordepended on the lubricant coverage and head mediainteraction. Furthermore, molecular dynamics methodwas applied to observe lubricant molecular distributionand the coverage changed as a function of lubricantthickness.

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We studied the effect of bias voltage between the slider and disk surfaces to reduce lubricant pickup by the slider. A perfluoropolyether (PFPE) lubricant film, which is coated on the disk surface, has been considered to be charged to a negative voltage by the air flow on the rotational disk surface. Because the PFPE lubricant film is negatively charged, the lubricant pickup should be reduced by a bias voltage with a negative voltage on the slider surface. We confirmed the lubricant pickup using a lubricant pickup test under different bias voltages. As a result, the positive voltage of the slider accelerated the lubricant pickup, and the negative voltage reduced it.

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A fundamental understanding of diffusion phenomena of submonolayer polar liquid films is important to achieve reliable lubrication. With the aim of gaining such an understanding, we developed an all-atom model that includes hydrogen-bond potential for polar perfluoro- polyether Zdol molecules and carried out MD simulations using this model. Comparing with experimental results, we confirmed that our MD simulations reproduce the effects of polar groups on the diffusion and conformation of Zdol molecules. Our MD simulations also demonstrated that, as the thickness of submonolayer Zdol films decreased, the molecular conformation changed from spherical to flat and the diffusion coefficient decreased. We suggest that such a change in the molecular conformation is the reason for the decrease of diffusion coefficient.

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Monte Carlo Brownian Dynamics simulations have been used to calculate structures of a polyelectrolyte brush grafted onto planes. The polymers were calculated in a semi-flexible coarse-grain model that is appropriate to treat the charge of the polyion. The effect of linear charge density on the polyion was studied. In salt-free solution, scaling theories predicted the structure well in the low region. In the high region, additional shrinkage was found from the theories due to counterion condensation. The other properties such as added salt effect, effect of surface charges and improvement of the molecular simulation will be presented.

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A tribochemical reaction mechanism between aluminum and polytetrafluoroethylene (PTFE) resin, which is widely used as bearing material, was investigated by a computational chemistry method. A catalytic effect of aluminum surface and its influence on wear behavior of PTFE were especially focused. The result suggested that the tribo-catalytically-formed aluminum fluoride causes wear of PTFE because of less transfer film formation which is necessary phenomena for lowering friction and wear. It was inferred that preventing the catalytic effect of metallic surface is one of the ways to suppress the PTFE wear.

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Superlubricity of the (graphene)_2/C_<60>/(graphene)_2 interface, C_<60> molecular bearings, is studied based on the molecular mechanics simulation. Effect of the multilayer graphene on the superlubricity is discussed. The lateral force curve shows characteristic sawtooth behaviour induced by the different slips at the different interface. The smallest peak discretely decreases due to the slip occurred at the C_<60>/graphene interface. On the other hand, the highest peak discretely decreases due to the multiple slip occurred at both the C_<60>/graphene and graphene/graphene interfaces.

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Atomistic research on friction is under way, with the aim of refining theoretical models that consider interactions between atoms beyond mean field theory and experiments using ultrahigh vacuum non-contact atomic force microscopy. Such research is expected to help clarify the nature of microscopic friction, reveal the onset conditions of friction and superlubricity as well as the stability of superlubricity discover new superlubric systems, and lead to new applications.

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This paper proposes a novel device of enhanced energy harvesting from stochastic resonant vibration, which can utilize ambient vibration with wideband and low frequencies. The suggested bi-stable cantilever was modeled using three kinds of numerical simulations and the feasibility of the stochastic resonant vibration can be confirmed by using ambient noise excitation.

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In recent years,a lot of attention has been paid onmicro/nanomotors for their potential use in micro-fluid,drug targeting, nano-sensors and pollution controlling.Most of the current micro/nanomotors are made ofpolymer or metallic materials which are difficult tomodify to satisfy various requirements. In this paper, aconical tubular micromotor which is composed of doublelayers of mesostructured silica and zinc, is proposedusing template electrochemical deposition method. Thepropulsion characteristics of micromotors are determinedfor different metallic materials. The mesostructuredstructures of micromotors are identified by EnergyDispersive X-ray (EDX), and Scanning ElectronMicroscope (SEM).

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Recently, the number of disks has been increased and the gap between the slider and disk has been decreased. These changes occur the contact between ramp and disk easily. The external shock and ramp-disk contact cause the change of disk curvature. The change of disk curvature affects air bearing pressure between slider and disk. However, the disk curvature is not considered on the previous researches. In the research, the simulation procedure was performed under the assumption that the slider and disk were paralleled. This assumption cannot reflect the real disk phenomenon. Therefore, this research investigates the influence of disk curvature under the shock condition.

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We develop a new laser Doppler measurement system for the evaluation of the dispersion stability of micro- and nano-emulsions with a spatial resolution in the range of nanometers. In future thermal managements, colloids in the form of micro- and nano-emulsions will play a major role of storing and transporting thermal energy produced by renewable energy source or energy waste. With the emulsions made of phase-change materials, a higher efficiency heat exchange can be achieved through latent heat compare to the sensible one. An important issue of the technology is the dispersion stability of emulsions under repeated phase changes (heat is stored in melting and released in solidification). The dispersion is achieved by the interaction of electrokinetic forces acting on the colloidal particles characterized by zeta potential. We use evanescent waves for measuring the zeta potential of emulsions at thermal interfaces. The use of evanescent waves can achieve a spatial resolution in the range of nanometers, which is never feasible with a conventional optical system bounded by the diffraction limit. We present the basic concept and the prototype design of the measurement system.

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We examined the dry friction properties of the nanostripe structures consisted of soft metal (Ag) and hard metal (Cr) on Si substrate with periodic slope array. The friction coefficient was measured between Ag-Cr nanostripe structure and six counterparts (Mo, Ni, Ti, Al_2O_3, SUJ2, Si_3N_ 4) using a reciprocating friction tester. The nanostripe structure showed friction coefficient of a 0.5 or more in the atmospheric air. In contrast, when the nanostripe structure was rubbed in a vacuum of 2×10^<-4> Pa, the friction coefficient decreased with number of the reciprocating motions and showed between 0.2 and 0.3 at the end of reciprocating friction. The nanostripe structure shows higher wear rate in vacuum than in the air. SEM-EDX (scanning electron microscopy-energy dispersive X-ray spectroscopy) observations showed that Ag film covered nanostripe surface on the wear track.

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A novel probe sliding system for probe-based memory based on scanning probe microcopy is presented. To obtain good electric contact stability, characteristics of the wear debris generated by sliding on the media surface are evaluated. An antiwear probe with a groove and oil lubrication (AGO) system is proposed to manage and reduce the wear debris. During a slide of 2 meters, stable electric contact was obtained by introducing these technologies.

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Metal/Metal universal joints reinforced by carbon fibers had been proposed to save the energy and to enhance the mobility of mover machines. The ductile fracture occurred at aluminum part in the Ti/Al joint with carbon fiber reinforcement (CFR). Although the tensile strength (σ_b) was slightly reduced, its strain (ε_b) and maximum strain (ε_f) of the CFR-Ti/Al joint with ductile fracture were 1.8 and 2.5 times higher than those of the Ti/Al joint with brittle fracture Ti/Al joint without CFR because of huge static and dynamic friction force induced by the high resistance to pull out narrow carbon fibers, respectively. CFR elongated not only theε_b and ε_f , but also enhanced the initial modulus value of dσ/dε. Based on the mixture law, increasing the volume fraction of carbon fiber enhanced the stiffness. CFR didn't increase the tensile strength (σ_b) much since the joint sample was melted and solidified, the process increased the grain size, resulting in tensile strength decreasing although strain and modulus were increased.

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Adhesive 2-layer lamination joints (18-8/CFRP) were prepared using a new adhesion method consisting of applying low dose (0.13 MGy) of homogeneous low energy electron beam irradiation (HLEBI) to both 18mass%Cr-8mass%Ni austenite stainless steel (18-8), and carbon fiber reinforced epoxy polymer (CFRP) prior to hot-press in vacuum below 1 Pa for 2 h at 401±0.5 K after lamination assembly. Although, application of 0.13 MGy HLEBI dose improved the tensile shear strength (τ_B) of the 18-8/CFRP joint 162 % at accumulative probability (P_s = 0.58) from 4.5 to 7.2 MPa. In addition, the τ_<B(s)> of 18-8/CFRP with the lamination method 0.13 MGy is slightly and much higher than that of 0.13 MGy-irradiated 18-8 and untreated CFRP prior to hot-press after the assembly, respectively.

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