In this study, we focused on the vibration of the scroll compressor installed in the outdoor unit of air conditioners. In order to reduce the vibration transmission to foundation, compressor is generally supported by the vibration isolation rubber. While the reduction for steady-state vibration during running has been studied, it is not enough to study the reduction of transient vibration in the startup of the compressor. Firstly, we identified the excitation force generated by compressor. Using this excitation force, we calculated the transient vibration and steady-state response. Finally, we proposed a support structure for low-vibration of compressor.

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Many air conditioners use fan systems for heat exchange. Vibratory motion and noise in the air conditioner occur when the aerodynamic force of the rotating fan blades act on the cabinet of the air conditioner. On the other hand, reaction force corresponding to the aerodynamic force occurs, and then the reaction force transmitted to the motor-feet. Finally, these transmitted forces excite support-structure of the motor. We calculated the aerodynamic force and pressure fluctuation on fan blades by CFD software "PHOENICS" and we also calculated the reaction force, using the results of CFD analysis. Based on the calculation result of pressure fluctuation on fan blade, we proposed the improved blade shape. Finally, we demonstrated that the proposed fan blade show good characteristics of the reaction force.

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It is necessary to perform sufficiently training in the laparoscopic surgery, however, the traditional training method is based on the skilled surgeon guidance. The objective of this study is developing a training system which can train surgical operation of ligation without any skilled surgeons' advices. First, difference of the operation features between skilled surgeons and intern surgeons is analyzed by measuring surgeon's hand positioning and the loaded force to the axis and the handle of the forceps. As a result, it is found that the amount of rotation of the wrists by skilled surgeon's operation is not as short as that by non-skilled surgeon's operation at wrapping in ligation. Secondly, an evaluating system for effective forceps operation of the right and the left is proposed on the basis of the amount of rotation of the wrists by skilled surgeon at wrapping in ligation and the time required for performing the wrapping in ligation. Then, the data at the wrapping in ligation is sampled by observing the trainee's operation movie. Finally, an interface for representing the evaluation results to the trainee is developed.

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The forceps robot and laparoscope robot for single-port-surgery have been developed in our previous study. The forceps robot is controlled by master slave control system using an input device Omega.7. Then, surgeon manipulates the Omega.7 with his both hands during the surgery. Therefore, he cannot manipulate the laparoscope robot with his hand. In this paper, a control method of the laparoscope robot without using hand is proposed. To this end, a biosignal acquisition headset, Emotiv EPOC, is used as an input device for the laparoscope robot. Three kinds of operator's face expression and two kinds of head movements of the operator are detected by the Emotiv EPOC. Then, operation method at the tip of the laparoscope is determined using these expressions and head movements. Thus, the target position of the tip of the laparoscope is given by operating the Emotiv EPOC. A control system of the tip position of the laparoscope is constructed based on the inverse kinematics of the laparoscope robot using the PID controller. In order to verify a usability of the proposed system, experiments on the view control with Emotiv EPOC were executed.

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Laparoscopic surgery is a difficult procedure compared with open abdominal surgery. Therefore, training is necessary for surgeon to enhance the surgical skill for laparoscopic surgery. In this paper, we propose a novel training system to train an operation of ligation in laparoscopic surgery. The developed training system presents operator's operating force of the forceps, sudden operation of the forceps and straining of the shoulder to the operator. The operator's operating force of the forceps is measured by strain gauges and is displayed to the monitor together with the target force which was pre-measured from skilled-surgeon, so that the operator can learn appropriate operating force of the forceps. In addition, operator's forceps operation and surface electromyogram of the back muscle are measred, and when the operator's sudden operation of the forceps and straining of the shoulder are detected, the operator is warned acoustically. Fundamental tests were carried out to verify working state of the developed training system.

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Currently, it is desired to incorporate force feedback into medical robots. In this study, a three-axis load measurement sensor mounted on the tip of forceps was developed. The newly developed sensor electrodes are three-dimensionally arranged. From the simulation, the effect of change in the load of shear load on the load measurement was revealed. The measurement was found to be affected by the bending and deformation. As a result, by measuring the normal load applied to each zone, this sensor can calculate the normal load and shear load.

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In this paper, we measured the relationship between the grasping position of the tissue model including a tumor model and the compression and shear forces detected by a grasping forceps with sensors during grasping. We prepared 3 types of tissue model made by gelatin. An acrylic ball as a tumor model was embedded in the tissue model varying the depth of the ball. The maximum compression force was detected at the right above of the ball. At the position, comparing the compression force detected at the each tip of the grapsing forceps, the compression force detected at the near side of the ball was larger than that of at the opposite side. Moreover, the shear force occurred in the direction toward the ball around the ball except for the right above. These results show that we can estimate the position, the depth and the direction of the tumor by measuring the compression and shear forces during grasping.

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Patients suffering from knee joint damage are generally only provided with subjective, qualitative feedback form physicians. This research sets the foundation for providing a quantitative, non-invasive feedback for knee joint damage by finding the center of rotation (CoR) of the knee joint. Knee joint motion analysis is usually performed through camera based optical tracking systems. Although these standard technologies allow a complete 3-D kinematics of knee, they require a dedicated laboratory. In this research a novel method of utilizing IMUs to obtain knee CoR is proposed. The merits of utilizing IMUs derives from its compact size, short diagnose time, thus putting less burden on patients. With IMU, acceleration and angular velocity can be measured. IMUs were fixed to the thigh and shank to measure the instantaneous CoR of the knee. Since the instantaneous CoR of the knee is different during normal and damaged condition, by obtaining the instantaneous CoR of the knee, one can quantitatively evaluate the conditions of the knee and provide outcome evaluation after surgery. It was found that for extension motion, good correlation coefficient was obtained from IMU and camera. However flexion motion showed much larger result than camera. This is assumed as the effect of inertia. In addition, calculating a 3D motion in a 2D plane may be a crucial reason effecting results. However it can be concluded that utilizing IMUs to diagnose knee function is adoptable in clinical fields for its easy accessibility and less burdens on patients.

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Estimation method of time required for 10 meter fastest walking is introduced. Because time of 10 meter fastest walking may suggest the possibility of early detection of dementia, walking time measurement is performed in current medical checkup as well as physical examination recently. Walking time of examinee is usually measured by an examiner following the walking examinee using a stop watch. In this study, two inertial sensors mounted on both tiptoe are used to measure stride length every step by double integration of tiptoe acceleration and to estimate the walking time taken for 10 meter walk. To derive walking trajectory from acceleration, determination of integral duration of each step is essential. In previous method, using resultant angular velocity of tiptoe, small and stable value due to stance phase and a peak due to toe-off was used to find gait motion and to determine the integral duration. However very fast walking performed by young examinee causes unstable angular velocity, and detection of gait motion was difficult . In this study, therefore, angular velocity of plantar/dorsal flexion is used to find swing phase, then moment of toe-off is found and integral duration is determined. 876 subjects participated in the 10 meter walking time measurement. The experimental resuls show that 334 subjects successfully provided 10 meter walking time estimated applying previous method but small correlation coefficient of r=66. Meanwhile 868 subjects provided 10 meter walking time and high correlation coefficient of r=0.95 app;ying proposed method.

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We have developed a system that greatly improves balance by removing visual information of the external world during gait training and further by visual feedback of somatic sensation information. The somatic sensation information used for feedback was foot pressure distribution and joint angle information, which is somatic sensation information used during gait. In the verification experiment, we compared training with the feedback system and the training in the visual sense cutoff state without the feedback system. The performance index of the balance ability was the standard deviation σ of right-and-left directions of the CoP traces. The result revealed that σ increased by 0.61 times by the FB training, and balance ability was improved. Further, the effect of the FB training was more significant than that of visual interception training. This suggests that the visual interception system improves balance, and that visual feedback increases its effects.

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For the evaluation of the usability and the physical burden of using products, average values of various biological information such as muscle activity measured by electromyogram (EMG) or energy metabolic rate are estimated. However, the force to be applied to a products and the posture are sometimes different because of difference of individuals and proficient at the product, there is often a limit in extracting motion feature and using for evaluation according to those procedures based on conventional Ergonomics. In this research, we proposed an analytical method that was available for capturing various movement features by merging the biological information signals and diplaying the tracks on two-dimensional space in the form of Lissajours Figures We have applied this method to the motion of handling work apparatus and confirmed its effectiveness.

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In order to reduce the increasing rate of accidents concerning elderly people at the age of 75 years or older, this paper discusses a tendency of accidents, its main factors, and the triggers of the factors by analyzing statistical data of the accidents. This study proposes a new method to reduce the risks of the accidents by introducing a mobile robot to detect the associated changing factors. We set a hypothesis of a law for the occurrence of accidents. The hypothesis is "An accidents occurs under changing factors.". As an example, the paper desrcibes a consideration of a mobile robot for an assist in preventing the elderly from slipping to fall. It is realized by detecting liquid on the floor as one of the changing factors, and assess the feasibility toward verification of the hypothesis.

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One of the risk factors for falls in visually impaired persons is difficulty to recognize a change of road surface slipperiness by white cane. Therefore, we propose a detector system of slipperiness change by measuring a coefficient of static friction between the white cane and road surface using the white cane with force sensor and inertial sensor. However, when the white cane knocks road surface, impulsive force acting on the white cane makes estimating the coefficient of static friction difficult. Therefore, we investigated a minimum time interval between knocking road surface and starting sliding the white cane that can estimate the slipperiness change by the coefficient of static friction, because the impulsive force decrease as the time interval increases. We measured and compared the coefficient of static friction of three road materials at different time intervals using an equipment swing and sliding the white cane. The result suggested that the slipperiness change which have the fall risk can be estimated, when the time interval is 0.10[s] and over.

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In this study, we have developed a system consisting of a microphone, accelerometer, vibration motor, Bluetooth modular, Smartphone in order of monitor the apnea and sleeping condition. The microphone is used for monitoring the apnea state by measuring the breathing sounds during sleep. When a heavy apnea state is detected the vibration motor will stimulate the body to awaken up the person. The accelerometer is used of monitoring the body movement so that the person will be awakened easily in the morning by a suitable vibration patterns in order to enhance the sleeping state. The smartphone is used to record and analyze the signals, and control the whole system.

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Ultrasonic densitometry is one of the methods promising as a non-aggression measuring method of a bone density. The ultrasonic method has much possibility theoretically due to use an elastic vibration. However, since the reliability of a measurement results is not enough, the ultrasonic method has not reached a clinical criterion. We aim at the development of a new determination measurement technique for a bone density which uses the guided wave of the ultrasonic in the present study. We conducted the experiment of the guided wave with porous round rods of the same material but different densities. And then we investigated the velocity dispersion of the guided wave with the frequency-domain representation of the semblance lance method, and estimated the bulk velocity of the specimens from the velocity-dispersion characteristics.

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Presentation of various softness feeling of complicated multilayer anatomical structures has been required for the medical robots. However it has not yet been realized, because the model of a physical and physiological multilayer softness has not been mane. And quantification of physiological multilayer softness is necessary to make the model. In this study, quantification of physiological multilayer softness was investigated. Subjects' finger touched hard or soft single-layer jellies and touched the double layer jellies of which upper layer was soft or hard, respectively in this experiment. After that, subjects evaluated in 5 categories of "softness feeling", "elasticity feeling", "wrapping feeling", "pushing feeling", "multilayer feeling". The results showed that the correlation was founded that "softness feeling" and "elasticity feeling", "wrapping feeling", "pushing feeling". And it was characterized with significant differences in all the jelly. Therefore, in quantification of physiological multilayer softness, it was suggested that "elasticity feeling" and "pushing feeling" are necessary. Next, it is needed to investigate the quantification of psychological multilayer softness using the sample of more "multilayer feeling".

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Recently, most of infants wear diapers in their daily life. Due to wearing a diaper, contact stimuli on skin causes dermatitis. The contact stimulus is measured by sensory evaluation. However, it is difficult to carry out sensory evaluation on infants. Therefore, a sensory system which can objectively evaluate the contact stimulus is demanded. In previous studies, we have developed a contact stimulus sensor using a polyvinylidene difluoride (PVDF) film and a strain gauge. However, influence of pressure distribution on contact stimulus feeling by human is not investigated. In this paper, a stimulation system of contact stimulus was developed in order to provide steady stimulus to human skin and sensor part. And a pressure distribution sensor is used as a contact stimulus sensor in order to investigate the influence of pressure distribution. In experiments, 4 kinds of diaper samples were evaluated by human sensory evaluation and sensor measurements. The sensor outputs were compared with human evaluated by human sensory evaluation and sensor measurements. The sensor outputs were compared with human evaluation values. From the results, it was found that a feeling of pressure is related to average pressure on the whole sensor, and a feeling of rubbing is related to degree of pressure concentration.

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Strength tests for single lap joint with two adhesive (AV138/HV998 and EA9309), various adhesive layer thickness (0.1mm, 0.5mm, 1.0mm, 2.0mm) and lap length (12.7mm, 25mm, 50mm and 100mm) were conducted to investigate effect of lap length and adhesive layer thickness. The joint failure stress is decreasing but failure force is increasing with lap length increasing. Furthermore, the joint failure stress is decreasing with adhesive layer thickness increasing. The result showed the effect of layer thickness that was reverse to theoretival knowledge for effect of adhesive layer thickness.

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An inferential statistical method for structural design/analysis was developed. On the traditional Monte-Carlo method, input values for structural analysis were assumed random variables with known distribution, mean, and deviation. In practical design, however, distribution, mean, and deviation of these input values are unknown but only small sample of these input values are available. Hence, the Monte-Carlo method for structural analysis was extended to inferential statistics.

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This report deals with a derivation of buckling load for plate buckling analysis and an experiment of thermal buckling temperature difference. Formulae to calculate the plate buckling load under several support conditions are derived. Formulae to calculate the thermal buckling temperature difference are also derived. Finally, an experimental results of thermal buckling of a plate under a condition, that upper and lower ends are simply supported and left and right ends are free, is demonstrated.

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This study focuses on a group of beetles that have unfolding-stable-type wings and aims to reveal their wing-folding/unfolding mechanisms. These beetle use their wing elasticity for deployment and can therefore quickly take off. First, on the basis of the reports of entomologists, the authors desrcibe the factors related to the actuation of insect wing folding and unfolding. Then, the detailed motions involved in take-off and wing storing in ladybird beetles and rove beetles are observed by a high-speed camera. The analysis of these movies reveals the detailed processes of wing-unfolding and folding in these two species. Intrinsic elasticity plays a major role in wing development in both species. In the case of wing storing, a ladybird beetle folds its hindwings into a symmetric pattern using a simple up-down movement of the abdomen, whereas rove beetles also use their abdomens for wing-folding, but their movements are more complex, and the crease patterns are asymmetric. Finally, the characteristics of each wing-folding mechanism are summarized and the potential for engineering applications are discussed. Wing-folding/unfolding mechanisms in these insects have various unique capabilities which will provide new possibilities for designing deployable structures.

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Considering long-term application of the nanocrystalline metals in space, the influence of the nano-scale void is investigated via molecular dynamics (MD). The deformation of nanocrystalline metals involves not only intragranular but also grain boundary (GB) deformation, and it is one of the important factors to explain the material characteristics. Due to this deformation mechanism, the nanocrystalline metals have the possibility to show the characterisitc for the nano-scale void that varies from conventional metals. Therefore focusing on the nano-scale voids, we perform uniaxial tensile test with the nanocrystalline and perfect crystal Aluminum. As the results, following two findings are acquired. 1) As to the nanocrystalline models, there is no obvious influence of the nano-scale voids. 2) As to the perfect crystal models, the dislocation activities around the nano-scale voids decrease maximum stress.

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Sound absorber "acoustic black hole", a kind of acoustic metamaterial, has been made in the new configuration to control three dimensional propagation of acoustic wave and tested in anechoic room. Acoustic black hole is composed "shell" and "core" and filling fraction of shell is important for acoustic propagation. In this study, filling fraction is controlled by number and size of bar made of PLA. Evaluation of its absorption is conducted from reflection and trasnmission calculated with sound pressure ratio around spherical structure. The result shows the new acoustic black hole can't improve efficient of absorption, but that it can considerably reduce reflection on the surface of absorber. Also, three dimensional refraction in new shell is confirmed, but concentration of acoustic wave behind acoustic black hole which the small refraction causes makes Noise Reduction worse.

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We propose a new morphing wing concept for wing twist using a specially designed spar consisting of two pipes. One pipe is a thick closed-section member that carries bending moments. The other pipe is the shape variable member and has open and closed sections. The combination of open and closed sections is designed to achieve an objective disribution of twist angles. The ends of the two pipes are connected at the wing tip side and the other ends are connected to the airplane body or motor, providing a torque at the wing root side. According to this mechanism, the wing tip side has a larger twist angle than the wing root side. We established a theoretical formula describing the twist angle of the spar that combines the open and closed section members. The feasibility of the theoretical formula was demonstrated thorough numerical simulations using finite element analyses.

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A novel method for correcting path length errors of a reflector antenna system using piezoelectric stack actuators is developed and its feasibility is investigated. Piezoelectric stack actuators are usually used for only pushing; therefore that causes some trouble in shape control of the reflector system. In order to overcome the problem, piston mode of wave front is utilized to make control inputs for the actuators positive value. Some numerical simulations are carried out to investigate the feasibility of the method. The results of these simulations show that the antenna gain is recovered adequately by using the developed method.

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As for the old Japanese child, it was common to have played actually touching simple tools, such as a "Yoyo baloon", "Beedama", "Ohajiki", and "Taketombo". However, the child of Japan of these days stops such play, and is playing the video game and the portable game. Now many young engineers and students who played the portable games and were educated after the development of computer technology are convinced that findings based on computer-aided engineering (CAE) are equally valid as those obtained in real life, because they have little experience of physical phenomenon. We consider the construction of "waribashi bridges" and "taketombos" as examples of PBL (Project Based Learning) projects to correct the discrepancy between real-life experience and virtual experience. That they make a waribashi bridge and taketombo with a knife supplements their shortage of a physical experience, and making the taketombo from 3D printer and NC machine improves their knowledge.

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Web-based simulation software for introductory physics course was developed using HTML5 technology. THML5, which is the latest version of HTML standard, include graphical extension called "CANVAS". By using CANVAS elements we can draw graphics via scripting in JavaScript, so dynamic animation of physical phenomena can be illustrated on a local PC as well as a smart-phone without installation of the software. In this study, we developed a series of software for physics education, for example parabolic motion, harmonic motion and oscillation. In order to confirm the effectiveness of the software, access analysis of the website and questionnaires to 1th-year students at our college were conducted.

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A mechanical design is important in the engineering department. The student's way of thinking is various, so individual counseling is necessary. And the difference in the achievements is expanding in recent years. Therefore individual counseling is becoming important. So all students had individual counseling using NFC in mechanical design. It was used to educate and the effectiveness using NFC is discussed.

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The Hokkaido Institute of Technology (HIT) established the Faculty of Advanced Engineering in 2008. The overall objective of the faculty was to offer a variety of curriculums, optimizing the specializations in each of the three departments, while also taking advantage of students' aptitude, for the purpose of ultimately cultivating engineers capable of contributing to the vitalization of both Hokkaido and Japan. Specifically, one of the departments, the Department of Mechanical Systems Engineering offers a 2-course system: a Robotics Course and an Engineering Course. The Robotics Course offers two Major Course subjects utilizing Autonomous Mobile Robots: Tutorial of Robotics I and II. This paper aims to verify the effectiveness of these exercise style subjects as Creative Engineering Education. Effectiveness was evaluated considering the contents of each subject, an evaluation questionnaire on the education for students.

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In industry-university collaborative education, the graduates who have experienced it may become the corporate liason for engineering students. As part of the training in their companies, it was found that the education will be responsible not only for engineering education to the students, but also for the corporate engineer education after graduation.

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This paper reports a trial for improving a communication skill at experimental exercises. For this purpose, a free vibration experiment with a spring balance to evaluate the spring constant is picked up, and the students attending the experimental exercise tried to set up the experimental procedure by studying the vibration together and by discussion for each other, and then they carryed out the experiment they had set up.

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I have developed a software called DSS which supports the sequence of operation of numerically solving the motion equation and displaying the analytical results graphically. DSS can deal with problems where the motion equation can be described in second order ordinary differential equation, with maximum of six analysis variables. DSS has four output ways of analytical result: GRAPH (a time history type), FFT (a frequency analysis type), ANIMATION (an animation type) and FREE (an optional type aiding users in completing their own program). Furthermore, a new function called MOVIE was added to DSS to be able to watch a real vibration phenomenon. In this paper, the outline of DSS is described first. Next, as an example, vibration phenomenon of three storey structure is simulated by using it.

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The derivation of the maximum projection angle in projectile motion of a particle gives one of the most popular examples in elementary mechanics. This procedure is also a typical example of optimization problem although it has not been emphasized in many textbooks of mechanics. We formulate the problem on the basis of the optimization approach, and obtain the perturbed solution in terms of aerodynamic parameters. This solution yields the optimum angles in the following three examples: simple projection with vertical displacement between launch and landing positions, projection with initial speed depending on initial angle and also projection under the action of fluid dynamic forces such as drag and lift proportional to flight speed. These results show realistic angles in several projection phenomena appearing in our usual life, and successfully explain the mechanism. This fact means the significance of optimization approach in elementary mechanics, and it will be effective to introduce this concept to early education in mechanics.

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The authors have developed for children and analyzed returnable toys. In this paper, returnable toys (boomerang stunt planes, bamboomerangs, and boomerang paper cups) and paper flying ring have been developed. These analyses are able to use as matters of education of mechanism for students of College of Technology. It is found that the text of practical mechanics are very much effective to technology education because of expected matters.

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The present study introduces the education methodology on engineering mechanics by using Schaum's outline series as a textbook at Department of Mechanical and Intelligent System Engineering, Hokkaido University. Schaum's Outlines are a series of supplementary texts for college-level courses that are published by McGraw-Hill Education, and cover a wide range of academic subjects. Texts of Engineerng Mechanics "Statics" and "Dynamics" in the series are used in the class, and the reason why these supplementary texts were chosen is explained. Some students' responses are given and the advantage and disadvantage are discused from educational viewpoints.

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In this paper, the influence of vacuum annealing on the mechanical properties of gold (Au) bonding wires is described. Au bonding wires with the diameter of 25μm are subjected to quasi-static uniaxial tensile tests at laboratory air. The bonding wire specimens are prepared by the attachment of a wire to a silicon (Si) frame fabricated by deep reactive ion etching (DRIE). The Young's modulus and 0.2% offset yield strangth are 113GPa and 310MPa on average. By annealing at 100〜300℃ for 10min in vacuum, the Young's modulus value gradually decreases with increasing annealing temperature, whereas the yield strangth value drastically drops in the annealed wires at over 200℃. The annealing effect is discussed in the light of a change in the number of recrystallized grains in the wires.

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Porous nanoparticles are very attractive as a carrier for next generation drug delivery. To reliably deliver the proper amount of a drug with to the diseased part, the size and porosity of the nanoparticles should be controlled precisely. The atomized heating method is one of the promising techniques for producing porous nanoparticles. To date, with the technique, porous nanoparticles made of various metal oxides, such as alumina, silica, and titania, have been made from these nano powders with the diameter of 10nm. The purpose of this study is to precisely control the particle shape and size, pore size, and porosity of porous silica nanoparticles fabricated using the atomized heating method. The produced silica nanoparticles are subjected to strength test in a scanning electron microscope.

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Physical and chemical properties of crystalline materials are strongly dependent on the atomic structure of grain boundaries. Accordingly, it is essential to investigate the grain boundary structure for understanding the properties. In this study, we focused on structure of dislocations at (0001)/[112^^-0] low-angle tilt grain boundaries in lithium niobate (LiNbO_3). The core structures of the boundary dislocations were observed by scanning transmission electron microscopy (STEM) and electric property along the dislocations were investigated. It was found out by the STEM observation that the (0001)/[112^^-0] low-angle tilt grain oundary consists of the three types of dislocations. This is probably because Burgers vector of [0001] perfect dislocation is too large to form. In addition, it was confirmed that all the three boundary dislocations dissociate into two partial dislocations with a stacking fault in between. The electrical conductivity measurement showed that a part of fabricated low-angle tilt grain boundaries developed electric conductivity although it is an insulator.

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A database of the extended Tersoff interatomic potential parameters is developed and presented in this paper. This database is a table containing parameter value sets for all elements of atomic number 1 to 83. Various properties of crystals and molecules are calculated by using these parameter sets and the results coincide well with the experimental results. This database makes it easy to execute molecular simulations which give us useful insight for developing micro-nano systems consisting of various chemical elements.

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To clarify the effects of vacuum on the room-temperature time-dependent deformation of Ti nanocolumns, we conducted monotonically-increasing-loading experiments with different loading rates and creep experiments using micro-specimens in laboratory air and vacuum environments. In the monotonically-increasing-loading experiments, critical apparent shear stress, defined as the critical force divided by specimen area, in air environment was larger than that in vacuum environment. The result indicated that an environmental effect existed and significantly influenced the strength. In air environment, the loading curves (apparent shear stress vs. displacement curves) were almost similar at the large loading rates 50 μN/s and 100 μN/s, whereas the fracture displacement at the small loading rate 5 μN/s was five times as high as those at the large loading rates. On the other hand, in vacuum environment, the loading curve at 5 μN/s was almost similar to those at the higher rates 50 μN/s and 100 μN/s. In the creep experiments, the Ti nanocolumns showed time-dependent deformation in both air and vacuum environments. The steady state creep rate in air environment was much higher than that in vacuum environment. These results suggested that the time-dependent deformation in the nanocolumns was significantly accelerated by air or moisture environment.

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Fatigue crack propagation experiments of approximately 500-nm-thick freestanding single crystalline copper (Cu) films were conducted to clarify the intrinsic mechanisms of fatigue crack propagation excluding the effect of microstructure such as twin boundaries in nano-films. A fatigue crack started to propagate stably from a single side edge notch by applying cyclic loading, and the fatigue crack propagated on oblique direction corresponding to the slip systems. Field emission scanning electron microscope (FESEM) observations of the vicinity of the crack and fatigue fracture surface indicated that fatigue damage penetrating the film in thickness direction formed. In addition, thin strips projecting in out-of-plane directions formed along the fatigue crack. In order to clarify the morphology by the fatigue damage, cross-sectional analysis of the fatigue damage ahead of the crack tip was conducted by using a focused ion beam. FESEM observation of the cross-section of the fatigue damage confirmed that instrusions/extrusions formed ahead of the crack tip. This suggests that intrusions/extrusions play a major role in fatigue crack propagation even in single crystal Cu films.

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Titanium tends to seizure with other metals, so titanium unfits thread rolling for dental implant with φ3mm diameter or less. Therefore we lubricate the contact point and prevent the seizure by applying a textured surface on the die. We were examined for the textured surface for reducing the shear stress by plastically deformed analysis between titanium material and die, and fluid analysis of the oil around the textured surface. From this analysis, texture provides an effective of low-friction, and a dimple type texture reduces shear stress by 28%.

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Glaze-based erbium oxide film was coated on alumina plate in order to enhance emittance of the substrate in the wavelength around 1.5 μm. Scanning electron microscope images showed that film structure could be controlled from glass to porous structure by composition of slurry. In addition, the erbium compound was composed of minute polycrystalline grains and separated from SiO_2 network in the film. The glass structure with much amount of erbium compound was seemed to be optimal to utilize specific infrared radiation emitted from erbium ions.

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Self-propagating exothermic reaction of Al/Ni multilayer film has been attracting us to utilize for solder joint process due to the enormous heat generation. In this paper, characterization of thermal resistance of the joint by self-propagating exothermic reaction bonding technique is discussed. Through the investigation of thermal resstance of the joint analyzed by response function method and thermal effusivity measured by thermoreflectance method, we found that thermal resistance of the joint is affected not only existence of cracks and voids but also thermal effusivity change of the reacted NiAl layer which depends on the pressure load during exothermic reaction.

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We have studied simulation method for surface-diffusion-driven evolution of high-aspect-ratio hole patterns. In order to reproduce the topological changes such as closure of hole openings and pinch-off of voids in the evolution of high-aspect-ratio hole patterns by simulation, phase field model based on Cahn-Hilliard equation with degenerate mobility is used. We show that our simulation reproduces well the observed evolution of high-aspect-ratio hole patterns. We also reveal the capability of the surface-diffusion-driven evolution to create different kinds of 3D micro-structures such as beams and cantilevers using this simulation.

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Focused ion beam (FIB) is well known as a powerful tool for directly forming micro/nano-scale 3D mechanical structures without photolithography. By using FIB with Ga+ ions, we are able to conduct local etching as well as Ga+ ion implantation. The combination of the ion doping and alkali wet etching to a single crystal silicon wafer enables us to fabricate a nanometer-thick Ga+ ion doped amorphous silicon membrane. The silicon nano-membrane will be utilizable as nano mechanical elements, such as nano force/pressure sensors and nano oscillators in nanoelectromechanical systems. If the nano-membrane can be reshaped to arbitral 3D shape, the utility value will increase. The purpose of this study is to develop silicon nano-membrane reshaping technique using Ga+ ion implantation with FIB. The membrane is made by the combination of Ga+ ion implantation and wet etching, and it is bent to arbitrary angles by controlling the beam irradiationcondition. The silicon origami technique allows us to manufacture a micron-sized airplane from a silicon nano-membrane.

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The Q factor enhancement of Si resonators using nonlinear damping is investigated for highly sensitive resonant sensors. The thermomechanical noise, which limits the physical resolution of resonant sensors, can be improved by increasing the Q factor. In this paper, the nonlinear damping effect of thin Si resonators was investigated and the Q factor enhancement caused by nonlinear damping is measured. The resonator thickness used for the Q factor measurements are 100, 400, 800, 1500 nm. The Q factor of the 100 nm-thick resonator is dramatically increased as its vibration amplitude become larger, while the Q factor change become smaller as the resonator thickness become thicker. These results show that Si resonators have the nonlinear damping effect, and the large Q factor enhancement by this effect is markedly observed in the thin resonator. It is concluded that the Q factors of nanomechanical resonators can be increased by only adjusting its vibration amplitudes.

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Some electrical appliance such as mobile phone has been miniaturized recently to be wearable while the size of electrical device worked into those appliances has been smaller and thinner remarkably. However the current device design has been done based upon bulk material data. In order to satisfy those technical requests, some testing device for measuring the mechanical property of very small material has been developed. Those devices become large size in spite of very small-size specimen in order to control precisely a testing wave form. To achieve more compact testing device, bending and bulge tests have been also proposed, although it is very complicated to assess directly stress-strain curve. The othre trial has been focused on advanced actuator system, piezo-electric actuator, instead of an electromechanical actuator. However, the origin of the problem on development of advanced testing system with more compact size has not been settled yet. In this paper, we report the desirable testing system which was achieved by involving some following idea: uniting of an actuator, a load cell and the testing part into device structure, and adopting shape memory wire as new actuator. In the design, fusion with analytical equipment is aimed to be able to grasp a damage evolution.

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Recently, there has been many researches and practical applications of submillimeter-submicron order structure, including the MEMS. In order to improve the reliability of these structures, it is important to clarify the micro-scale material properties. Generally, material properties are considered to be constant regardless of the size of the structure. In the micro-scale, however, it is said to have different material properties in the macro-scale, and in particular, the fatigue behavior differs when the structure is small compared to the micro-cracks (〜 10 micron). Therefore, there are many researches to study the fatigue fracture properties of a micro structure, but following problems still remain: Observation of real-time fatigue behavior of the specimen, Accurate load measurement and Simultaneous measurement of load and deformation. To solve these problems, we proposed and developed a micro-scale bending fatigue test system that enables real-time observation and accurate load measurement. And with this system, we tested specimens made of single crystal silicon, which is commonly used in MEMS, etc.

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Wurtzite (AlTi)N with high crystallinity has the NTC (negative temperature coefficient) thermistor property, which is applicable to an ultra thin temperature sensor on a thin polyimide film. The flexible sensor actually requires the mechanical reliability for operation, thus, the mechanical property, especially the toughness of the interface between an (AlTi)N thin film and a polyimide film was quantitatively evaluated by sub-micron scale fracture test. In addition, the effect of the fabrication process on the toughness was investigated with different types of specimens in order to elucidate the mechanism of the interface adhesion.

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