The necessity for the development of micro power supply technologies for mobile phones and portable electronics has increased in recent years. Methods of self power generation using the vibration loads of structures have attracted attention as the power supply technologies. In this study, we focused on lead zirconate titanate (Pb(Zr,Ti)O3, PZT) as the generating piezoelectric element. The purpose of the study is to develop a high-efficiency PZT generator element that utilizes the vibration loads in the support members of a structure. However, piezoelectric elements only generate power in the order of several microwatts, so improving their power generation capacity is of the utmost importance. In this paper, experiments of driving the accelerometer for continuously driving using the laminated PZT elements are reported. The accelerometer module device was composed of capacitor, switching circuit, voltage sensor and accelerometer module. The charges generated from the laminated PZT element are charged by the capacitor. And it reaches to the Accelerometer module through the switching circuit. As a result, it is possible to obtain the acceleration information. In this experiment, Receivable distance of the data has been evaluated. Based on these results, we confirmed the continuous acceleration sensor drive.

We have investigated the damping mechanism of a granular material damping system applied to reducing vibration in structures that have a high natural frequency and small vibration displacement. On the basis of the fundamental idea that damping effect can be obtain by dynamical motion of the granular materials, we discuss the motion of the granular materials by classifying then into translational moving granular materials and rotating granular materials. The relationship between the damping characteristics of the granular material damper and the dynamic motion of the granular materials was clarified from the number of the moving granular materials.

We have studied the damping mechanism of a granular material damping system applied to reducing vibration in structures that have a high natural frequency and small vibration displacement. As a study for practical use of granular material damper, experiments and calculations were carried out using spherical and cylindrical granules for changing granular size and material. As a result, it was confirmed that even if both size and material of the granular materials are different, the same damping effect can be obtained when the total mass of the granular material is the equal.Therefore, high density of granular material has good effect for saving the space of granular material container.

Most hybrid two-phase stepper motors are driven in open-loop drive algorithms such as full-, half- and micro-stepping. The open-loop positioning is achieved by counting the step command pulses. The fact that an expensive position sensor is not needed, makes these motors very appealing for industrial and domestic applications. However these open loop stepper motor drive methodologies do not detect step loss or stall of the rotor. To avoid step loss or stall, these stepper motors in open loop mode are driven with maximum current. This results in a poor energy-efficiency. When position feedback is available, the load angle can be measured and the drive current can be optimized. However, a position sensor adds costs and complexity to the system. This paper presents a method of load angle estimation of hybrid two-phase stepper motor in micro-step operation without the use of position sensor. This method is solely based on the current rise time variation due to back emf voltage. Measurement results are presented, showing validity of the load angle estimation algorithm.

Since the rocking vibration of structures, that are office furniture and computer server installed inside buildings, affects the overturning, it is important to understand characteristics of rocking vibration. In order to investigate the behavior of rigid body by rocking vibration, excitation experiment by sine wave and numerical response analysis were conducted. Validity of the numerical analysis was conformed from the comparison between experiment and numerical results. From the results of experiment and numerical analysis, under the condition of forced vibration frequency lower than 3Hz, the rigid body overturned when the acceleration amplitude over than the level of static overturned acceleration. On the other hand, over the condition of forced vibration frequency higher than 3Hz, it showed the rocking vibration.

The authors have proposed a small size spherical damper using silicone oil so as to reduce seismic response of the house in horizontal and vertical directions. And the damping effect of this damper is verified. In addition, regarding this damping effect, we considered that the diameter ratio between the inner diameter of damper and the inner diameter of the damper is dominant, and selected an effective combination of this diameter ratio and the kinematic viscosity of silicon oil. However, with respect to the diameter ratio, there is no study on the case of changing the diameter of the inner partition wall of the damper. Therefore, in this study, we attached two types of dampers with different inner diameter of damper, to house model and response characteristics of the model are measured by sweep excitation experiment and free vibration experiment. As a result, it was found that the damping effect greatly depends on the diameter ratio of the inner bulkhead and the inner sphere.

In a plating process, a steel plate is conveyed for 20-50 m in the vertical direction for drying, during which it is weakly supported by rollers or other devices, resulting in uneven plating due to vibration and other productivity-reducing factors. We developed a non-contact guide system for a high-speed traveling elastic steel plate in which electromagnetic forces are applied by actuators on the edges of the plate to control its position. Furthermore, in order to achieve stable control even with a small control current, it was used in conjunction with a permanent magnet, and it was verified whether stable guidance can be performed by arranging in consideration of vibration mode shape. We report the results of our experiment and simulations to show the effectiveness of our proposed method.

Recently, expansion of drone applications has been expected, and payload delivery using drones is one such application. In this study, we consider a case in which a quadrotor carries a suspended payload and investigate a control scheme to eliminate oscillation of the payload caused by quadrotor maneuvers. We assume a model that has an offset between the suspension point and the center of mass of the quadrotor and derive the equations of motion. The input shaping technique is applied to the velocity control of the quadrotor to suppress the payload oscillation. Finally, the effectiveness of the input-shaping-based velocity control for payload oscillation suppression is verified through numerical simulations.

The response of the vibration control system using swarm intelligence for random excitation has been investigated. As an example of swarm intelligence, a swarm of ants can find an optimal route between their nest and the food in various environment using special pheromone. In this sense, the network of agents in a swarm may have some kind of intelligence or higher function appeared in a simple agent, which is defined as the swarm intelligence. The concept of swarm intelligence may be applied in diverse engineering fields such as flexible pattern recognition, adaptive control system, or intelligent monitoring system, because some kind of intelligence may emerge on the network without any special control system. In previous studies, the swarm intelligence was applied to a mechanical vibration control system composed of a network of units equipped sensors and actuators. Five units composed of a displacement sensor and a variable damper were placed on each mass of the system. A unit composed of a sensor was placed on the basement. Each unit was connected to each other to exchange information of state variables measured by sensors on each unit. Because the network of units configured as a mutual connected network, a kind of artificial intelligence, the network of units could memorize the several expected vibration-controlled patterns and could produce the signal to the actuators on the unit to reduce the vibration of target system. In this study, the vibration control system was excited in random excitation. The results showed the possibility that the vibration control system could reduce the vibration, especially the response for natural frequencies.

The chain is a machine element which performs transmission of power by the tension. The bush chain is one of types, and it consists of pins, bushes, inner plates, outer plates, and joint links. Because pin pieces bush, friction occurs between pin and bush as the friction surface during operation. However, the friction occurrence decreases by the lubricant which is permeated in the chain, and smooth operation is carried out. The purpose of this basic study is to examine the effect of lubricant kinematic viscosity. This basic study focuses on the bulk temperature rise and transmission efficiency as the load-carrying characteristics during operation of bush chain. The data obtained by the difference in kinematic viscosity of the lubricant. As the result; (1) When bush chain drive is continued, bulk temperature becomes equilibrium temperature, (2) When the viscosity of lubricant is decreased, equilibrium temperature is increased and transmission efficiency is decreased, Based on these findings, the authors argue that there are definite relations between viscosity of the lubricant and the operation of bush chain.

Micro-gear is expected particularly to be applied to medical devices and space development in the future. Therefore, the final objective of this study is to clarify the load-carrying characteristics of micro-gear. The authors carried out an acceleration endurance test with phosphor bronze micro-gear of 0.1 mm module under lubricating oil dropping condition. The deflection of the gear shaft that generated during the acceleration endurance test by load torque was measured by laser measuring instrument and was canceled by to adjust gradually the Xstage of test equipment. The number of load cycles of the endurance test of one operating condition is 107. The load torque is gradually tightened until the power transmission becomes impossible. In this study, the acceleration endurance test was conducted under two different operation conditions. Specifically, lubrication oil properties and rotation speed were changed. Using the result, the authors examined how the difference of lubrication oil properties and rotation speed affect the load-carrying capacity of micro-gear. As the result, the authors obtained the following result ; (1) the damaged form of phosphor bronze micro-gear with 0.1 mm module under lubricating oil dropping condition was due to tooth wear. (2) The required lubrication oil properties for the load-carrying characteristic of micro-gear, under lubricating oil dropping condition, may vary greatly depending on operation condition.

To develop high performance polymeric tribomaterials fot mechanical sliding parts such as gears, bearings, seals and so on, the influence of surface treatment of fillers on the tribological properties of nanosized calcium carbonate (nano-CaCO₃) filled polyamide 66 (PA66) nanocomposites were investigated. The nano-CaCO₃ was a kind of precipitated (colloid typed) CaCO₃, and its average particles size was 40, 80 and 150 nm. Three types of surface treatment of nano-CaCO₃, namely fatty acid (FA), linear alkylbenzene sufonic acid (LAS) and maleic anhydride acid (MA) were used. Its volume fraction in the nanocomposites was varied from 1 to 20vol.%. These PA66/CaCO₃ nanocomposites were extruded using a twin extruder, and injection-molded. The mechanical properties and tribological properties were evaluated by the ring-on-plate type sliding wear test. It was found that the influence of surface treatment of nano-CaCO₃ on the frictional coefficient and specific wear rate of PA66/nano-CaCO₃ nanocomposites is differed by the type of surface treatment, particle size and volume fraction, although the surface treatment has a good effect on the tribological properties. This may be attributed to the change of wear mechanisms, which is the change of forming the transfer films on the metal counterpart and the size of wear debris. It follows from these results that surface treated nano-CaCO₃ filled PA66 nanocomposites may be possible to be the high performance tribomaterials.

The structures and the machinery by which social infrastructure is supported possess many splices. Among them, screws and bolts are often used as fastening means. Such structures and machinery are constantly receiving some sort of long-period external force. These external forces cause loosening or breakage of the screws and bolts of the fastening part, which may result in damages to the structures and the machinery. In recent years, a derailment of the roller coaster by slack bolt and backwards running accidents by the slack of the motor base fixation bolt of the escalator occurred. As the measures to prevent such accidents, a periodic inspection of the fastening state confirmation of the bolt is carried out. However, there are problems of time and labor, the increasing cost for the check by the workers, and a question remains concerning the precision of the check. Piezo-cables that we focused on in this study are piezoelectric elements having a piezoelectric effect that generates a voltage in response to external force. Then the piezo-cables can be used for the inspection not requiring workers such for damage of fastening elements and fatigue cracks of structural members. Therefore, in this study, we have developed a sensor which can monitor the fastening condition from the change of the shear load applied to the bolts using a piezo-cable. By doing this, it is possible to construct a system of self-check function and to prevent accidents. The results of this study shows that it is possible to determine the fastening state of the bolts using the developed sensor.

In this paper, we analyzed influences of environmentally acceptable lubricants (EAL) with natural seawater on tribological characteristics of stern tube bearings by using 3-pin on disk frictional test apparatus with specimens for stern tube bearing material and propeller shaft material. We focused on 4 types of lubricants, traditional mineral oil, saturated ester-based EAL, unsaturated ester-based EAL and non-ester-based EAL, and evaluated the frictional characteristics under various operating conditions by using stribeck curves. As a result, even if natural seawater enters mineral oil, frictional characteristics of this oil do not change significantly. However, frictional characteristics of saturated ester-based EAL and unsaturated ester-based EAL are affected by mixed natural seawater. When natural seawater is mixed in this saturated ester-based EAL and roughly eight weeks passed, friction coefficients between stern tube bearing material and propeller shaft material are larger compared with that without natural seawater. When non-ester-based EAL is used as the lubricating oil for stern tube bearing and the propeller shaft, its friction coefficient becomes very large.

In order to elucidate the lubrication mechanism of oiliness agents, there has been a growing interest in interface structure and physical properties of adsorption films. To comprehend the interface structure and physical properties of the oiliness agent, analytical apparatus with high resolution in the direction of film thickness in the solution is required to measure the solid-liquid interface in nano-orders. Application of Frequency Modulation Atomic Force Microscopy (FM-AFM), which has greatly sensitivity compared with conventional Amplitude Modulation AFM (AM-AFM), enables us to measure liquid structure contact onto solid surface. In this study, the observation of adsorption film structure and repulsive force mapping in the direction of film thickness (Z-X force mapping) in stearic acid solution were conducted using AM-AFM and FM-AFM. The AFM results indicated that the stearic acid derived adsorption film on mica consists of two regions: a pinhole region and a flat region. The Z-X force mapping results of FM-AFM also indicated that the pinhole region had a wider repulsive force compared to than that of the flat region.

In mechanical parts, it is important to supply an oil lubricant to the sliding surface for preventing oil starvation not to cause seizure and finally machine failure. In order to improve the frictional properties, a novel tribo-surface, termed a 3D capillary structure, has been proposed. It can collect excessive lubricant from sliding surface and supply it again into sliding interface by utilizing meniscus effect. The 3D capillary structure was manufactured by a metal 3D printer, because of its complex micro-structure. The bronze was focused as sliding material. In this study, the oil lubricant supplying function and frictional properties of the 3D capillary structure were investigated. To confirm the oil lubricant supplying function, a sliding test was conducted and observations were made by a camera. To compare the frictional property of a 3D capillary structured specimen made of bronze, a non-textured specimen made of bronze and a 3D capillary structured specimen made of stainless steel were manufactured. Experimental results showed that the 3D capillary structure made of bronze exhibited oil lubricant supplying function and the lowest friction coefficient. It is considered that the 3D capillary structure is a novel tribo-surface that is more effective for friction reduction and the frictional property of the bronze is better than that of stainless steel.

In this report, dynamic behavior of real contact of paper-based wet friction material subjected to fluctuating contact pressure is investigated experimentally. Real contact area is measured by a contact microscope that utilizes the light characteristics of total reflection and polarization. A strobe light source is used to obtain the contact surface image at an arbitrary phase in the cycle of contact pressure change. It was observed that, in wet condition, the normalized amplitude ratio of real contact area to contact pressure decreased with the exciting frequency and was much smaller than in the dry condition tending to increase the difference. Also it was recognized that, in wet condition, the phase delay of real contact area to contact pressure was enlarged with the frequency and was larger than in dry condition.

It is said that friction characteristics can be changed by controlling the adsorption of ions to the surface under applying voltage. There are, however, few reports about the relationships between frictional property in macroscale and adsorbed ions under applying electric voltage. The purpose of this study is to investigate the effects of the electric voltage on frictional property of ionic liquid by using the custom made sliding tester and atomic force microscopy (AFM). In this study, 1-Butyl-3-Methyl imidazolium Tris Pentafluorethyl-Tris Fluorophosphate [BMIM][FAP] was used as lubricant. When negative voltage applied, [BMIM][FAP] showed lower friction coefficient than the case of neutral voltage. On the other hand, when positive voltage applied, this liquid showed higher friction coefficient than the case of neutral voltage. The result taken by AFM showed similar friction behavior. According to the surface analysis by TOF-SIMS, it was found that the adsorption ratio of cations increased on the surface by the application of negative voltage and the adsorption ratio of cations decreased when positive voltage was applied. It is considered that the change in friction behavior due to voltage application dominates the adsorption ratio of cations on the surface.

Many researches about mechanical properties of objects fabricated by selective laser melting (SLM) have been done. However, there have been very few reports about tribological properties. Then, friction and wear characteristics of 630 stainless steel fabricated by SLM under oil lubrication were investigated in this research. Wear of the specimen with higher porosity increased enormously. It is supposed that metallic particles generated from the voids along with repeatedly stress concentration promoted abrasive wear of the specimen surface. On the other hand, wear resistance of the densest specimen which is properly heat treated is compatible with the conventional material.

Recently, many researchers have been regarding as important to realize high flight performance such as an insect's and bird's flights adopting an idea of bio-mimetics for the sake of precise and prompt survey of situation of disaster, development of the Mars airplane. Additionally, various studies of micro air vehicle (MAV) and unmanned air vehicle (UAV) have been reported from wide range points of view. In general, important features of the aerodynamics of biological flapping flyers result from large flapping wing movement and rotation, small size and low flight speed. In this study, the flow around a flapping model at a lower Reynolds number of 2.18×10⁴ is investigated. Various wings made of ABS resin with different taper configurations along span and chord wise directions were manufactured by three-dimensional printer. The fluid force measurement by six-component load cell and PIV analysis are performed as the experimental method. We investigated that the relation between the aerodynamic characteristics and fluid phenomena such as the layout of the leading-edge, trailing-edge and wing-tip vortices through wind tunnel experiments and PIV analysis.

Recently, various studies of micro air vehicle (MAV) and unmanned air vehicle (UAV) have been reported from wide range points of view. The aim of this study is to research the aerodynamic characteristics of delta wing in low Reynold's number region to develop applicative these air vehicles. Leading edge flap (LEF) is as an attractive tool for delta wing. Various configurations of LEF such as upward and downward deflected flap are used to enhance the aerodynamic characteristics in the delta wing. In this study, the numerical simulations are performed based on the model in which different shaped leading edge flaps are assembled in the delta wing at various mounting angle to obtain good aerodynamic characteristics. Additionally, the fluid force measurement by six component load cell and PIV analysis in plane of laser light sheet are performed as the experimental method. The relations between the aerodynamic effects of the LEFs and the vortex behavior around the models are demonstrated.

This paper describes the experimental results of the influence of the DC discharge plasma generated on the diamond airfoil in a Mach 1.41 airflow. The experiments were carried out in an indraft supersonic wind tunnel installed with the Laval nozzle. The discharge was generated between a pair of electrodes mounted on the airfoil surface. Current and voltage measurements indicated that the discharge became unstable at low power consumption. When the backpressure ratio of P_b / P₀ is in the range of 0.1 to 0.13, it was possible to generate plasma with 79.5 W of discharge power at 0.019 s intervals. In the case of 0.23 < P_b / P₀ < 0.26, the discharge period reduced to 0.013 s and the power consumption decreased to 50.7 W. From the visualization image of the flow field, the expansion wave from the entire plasma emission region was observed, and slight increase in the boundary layer thickness was seen at the downstream of the electrode. In order to detect the effects of the plasma on the supersonic airflow, a total pressure in the plasma discharge region was measured. It was suggested that the total pressure in the plasma discharge might be higher than without discharge but confirming of the reproducibility is necessary in the future investigation.

The smart bolts have been developed as health monitoring technology for composite fittings used in aerospace structures. One of the problems for the conventional smart bolts is undesired strain outputs variation in bolt radial direction. Recent studies have reported that the strain output radial dependency of the smart bolts can be suppressed by reducing the diameter of a hole that the fiber optic strain sensor embeds in. However, it is difficult to create a sufficient small diameter hole in the hard metal bolts used in the aerospace structure. In this study, a new method was developed to suppress the strain output radial dependency of the metal smart bolts for appropriate structural health monitoring of bolted joint structures. A small diameter hole for the smart bolts was created with two steps. At the first step, epoxy resin was infused to 1 mm diameter hole of a metal bolt and cured. Sufficient small diameter hole for the fiber optic strain sensor was created in the infused epoxy resin of the metal bolt at the second step. Tensile tests of a metal bolted joint with the metal smart bolt were performed to obtain the strain output with the bolt angle from 0 degree to 360 degree every 45 degree. Comparison of the outputs of the improved and conventional smart bolts showed the significant decrease of the strain output radial dependency of the improved smart bolts.

In this study, we observed the liquid infiltration process into closed-end holes by impingement of a droplet train with high speed video camera. The high liquid infiltration rate can be achieved by impacting a droplet train, compare to a liquid column impact. The high-speed photography reveals that the trapped bubbles inside the holes were broken up and rose while oscillating repeatedly before ejecting. We considered that these results are due to the differences of the applying pressure between a droplet train and liquid column. Furthermore, the results for applying a pressure oscillation with under water speaker were discussed.

In this study, we measured share forces generated during brush sliding with different sliding speed and brush rotation. We also observed the brush deformation during brush sliding with a high-speed video camera. The share forces were increased with the increase of brush sliding speed and decreased with the increase of brush rotation. Large deformation of brush was observed without brush rotation. However, the brush deformation was suppressed by the brush rotation. From these results, we conclude that part of the shear forces was generated by brushes deformation, not the contact condition.

Flow characteristic of cleaning liquid on a rotating semiconductor wafer were experimentally investigated. Flow pattern was recorded by a high speed video camera. Replacement characteristics of rinse liquid by cleaning liquid were investigated. For the estimation of replacement characteristics, UV fluorescence method was used. Dye solution was mixed with the water to obtain the fluorescence. Effects of rotational speed and flow rate on the rinse liquid replacement were measured.

Evaporation of droplet on a rotating wafer was experimentally investigated. Evaporation and movement behavior of droplet on wafer under centrifugal acceleration field were visualized by a video camera. The centrifugal acceleration was measured by an acceleration sensor. As the result, it was confirmed that maximum acceleration size was strongly influenced by a droplet size. In the previous research, the evaporation behavior of droplets have predicted by a simple diffusion model. In this study, the model was modified for the effect of air flow on the rotating table. Ranz and Marshall's evaporation model was used for the prediction of droplet life time. As a result, the results of the model were agreed with the experimental data.

The study on adhesion and desorption mechanism of nanoparticles near to polished wafer surface is necessary to efficiently clean the nano-particles from the wafer in semiconductor manufacturing process. This report proposes an optical method to visualize only the nano-particles moving near to Si₃N₄ and SiO₂ film surfaces by applying an evanescent field. We generated the evanescent field locating in limited range from the film surfaces by reflecting a laser beam at an incident angle larger than critical angle. Adhesion and desorption phenomena of the polystyrene latex standard particles (50±1 nm) and the SiO₂ particles (55 nm) moving near to the Si₃N₄ and SiO₂ film surfaces were observed by our developed experimental setup. Furthermore, desorption phenomenon of SiO₂ particles (105 nm) with the flow occurred by polyvinyl alcohol (PVA) sponge brush sliding was also demonstrated.

Miniaturization and high performance of robots familiar with MEMS technology can be achieved. The aim of this study was to investigate the expose both sides of a hollow cylindrical substrate. The principle only the point where light irradiated from the many directions crossed with one point is exposed. In the simulation calculation, we observe the path of light by using light as a linear equation. We used calculation software called Mathematica for calculation. The results of simulation demonstrated that the path of light was seen. This investigation has revealed that it can be inferred how the light diffuses, and where position the exposure is the best. Based on the simulation results, both sides of the hollow cylindrical substrate are exposed and evaluated. As a result, it was confirmed that double-side exposure to a hollow cylindrical substrate was possible. We will increase the number of exposure directions in the future.

In recent years, the MEMS market has shown a growth rate of more than 11% per year. However, there are various problems in manufacturing a MEMS device. One of them is that there is no common platform for evaluating the characteristics of MEMS devices with low cost. Because the MEMS device is a micro size device, it is costly to perform characterization. Therefore, it can only be done by a specific research institution. We consider a novel system of construct a common platform that can evaluate vibration characteristics of MEMS devices cheaply. An optical pickup unit was used in order to evaluate the characteristics of a micro size MEMS device at low cost. By measuring the resonance point of the cantilever actually using the optical pickup unit, we were able to measure the resonance point of the cantilever using the optical pickup. In the future, from the signal of the photodiode of the optical pickup, the displacement of the cantilever during the excitation vibration can be obtained as concrete value.

In this study, the effect of the wall surface property on the flow near the solid-liquid interface is experimentally clarified by measuring the velocity profile in the vicinity of the wall surface. We prepared 4 types test walls; agar walls with the concentrations of 0.75% and 1% as the hydrogel surface, and hydrophobic coating walls with silicone oil 10 Pa・s and 100 Pa・s as the lubricant-impregnated surface. Distilled water was flowed through the channel with test wall, and the flow was visualized by a high-speed camera and a slit laser. From the obtained image, the velocity profile was determined by the PIV method. Experimentally showed the possibility that a slip length may occur on the wall surface excluding the lubricant-impregnated surface of 100 Pa・s. It was found that the lower the concentration of the hydrogel wall surfaces, the slip length on the wall surface becomes larger. On the other hand, in order to observe the internal flow of the hydrogel, the ink for the fountain pen was injected inside the hydrogel wall. The state of the ink which was affected by the upper stream of the hydrogel was observed. As a result of observation, it was proved that there is internal flow near the surface of the hydrogel wall, and slip phenomenon may occur on the hydrogel wall surface.

A development of cell surgery technology is important to maintain and manupirate indivisual cell for cell therapy. The cell surgery technology is consisted with three techniques; cell manipulation, gene transfection and cell accesement. These techniques have not been established yet. In this study, the cell surgery device using electrokinetics under a local electric field around a sharp electrode is proposed and confimed experimentaly. First, selected cells are captured by dielectrophoresis and measured their properties using dielectric spectroscopy. Next, membrane pores are generat by electroporation with a local electric field. Finally, substance is transported into cell supported with AC electroosmotic flow. Experimental results of CHO cells were confirmed this technology.

In recent years, regenerative medicine technology attracts attention. It is a technology to extract cells from human organs and tissues and to create new organs and tissues by culturing in large quantities. However, unintended unusual cells are appeared during culturing of cells, which need to be removed. Therefore, in order to separate cells with high efficiency and label free, we aim to sense normal cells and unusual cells by intrinsic electrical properties. In this study, a cell mass spheroid was used as a measurement target. An attempt was made to find the difference in relative permittivity and conductivity of cell spheroids. As a result, differences were obtained at specific frequencies for relative permittivity.

Development of highly efficient cell sensing method is needed in the field of regenerative medical. Electrochemical impedance spectroscopy (EIS) method are progressing as a noninvasive cell measurement method. When the EIS method is applied to a cell suspension at a concentration in a culture environment, the electrical characteristics of the cells cannot be clearly measured. On the other hand, when compared with the sucrose solution used for the dispersion medium, impedance of the cell suspension is decrease. In this study, we measure decrease of impedance of the cell suspension in microchannel. As a result, it was found that there is a difference in the decrease rate of impedance of different cell type suspension and it is useful for cell identification.

In today's educational sites, the introduction of “active learning”, opportunity of independent learning and cooperative learning, into education is required. “Nazo-toki” is a kind of problem-solving game which participants challenge to solve and complete all problems, such as puzzles and quizzes, in a fictional story given. The problem-solving game activity “Nazo-toki” is intended primarily as an advertisement and an entertainment to attract customers. By incorporating the problem-solving game activity into education as a tool, it is thought that learning efficiency of children and their interests are more effectively improved. An education material to study the fundamentals of tribology for children using problem-solving game was developed and practiced it in an actual educational event. The title of the event is “Pyramids crisis!? SOS from the king of ancient Egypt!!” The subject of this event is mainly schoolchildren. When successively solving the problems, participants have to perform a measurement of surface roughness and an experiment of friction. And, they experience the effect of decreasing friction by using rollers as a final problem. From the result of the survey after the event, the degrees of attention and understanding to tribology was very high, and they had fun experiencing and learning tribology through this activity.

In order to evaluate an educational effect of an education program for the Problem-Based Learning (PBL) type creative design and manufacturing, this paper describes on the evaluation of manufacturing abilities using rubrics. In the ability evaluation, we propose a rubric consisting of 21 evaluation points. And based on the characteristics of each lesson, we decided to select five evaluation points from 21 evaluation points for each class. The educational effect of this PBL education program will be objectively confirmed by comparing with the results of PROG (Progress Report on Generic Skills) test.

The purpose of this study is to offer construction of educational environment and development of e-learning teaching materials towards educational support for working adults and local residents. Education and research institute of information technology of college of science and technology, Nihon University has provided the qualification course of CATIA Certified Professional over many years. Especially, we developed e-learning materials to raise the pass rate, and the pass rate was more than 80 percent. In this study, we report the status of the implementation of the CATIA Certified Professional and CATIA V5 Associate courses for supporting the working adults and local residents.

Disc brake has been used in many applications not only in automobile but also, industrial and railway engineering. However, the brake operation at low speed may create a squeal which cause an unpleasant experience to the passenger. In the research of squeal suppression, active control has the advantage due to its adaptability in design of the control system. However, the verification of the determination of the emerging stage of the squeal has not much been in attention. The high efficient method for determination of the brake squeal is required the accuracy, robustness of the noise from the vehicle and capability to determine the emerging stage of the squeal as earliest for the determination of the squeal. This research presented the verification of the accuracy of the brake squeal determination method, as well as the construction of its sequential algorithm which shorten the required time in the simulation. In this research, we introduced the Hilbert-Huang transform (HHT) for analyzing the nonlinear and unsteady signal. The simulation was performed by analyzing the signal, which was measured from the experiment of brake in laboratory and in practical vehicle, with HHT and other analysis such frequency transformation and time-frequency transformation. Then, the simulation results from each analysis method were compared in order to verify the accuracy of the determination method. Moreover, since the analysis using the HHT required much calculation time, we constructed an algorithm which can shorten the calculation time by recursively analyzing the data of signal. In conclusion, the analysis with HHT gave the highest robustness against the noise of the vehicle during braking when compared with other frequency, or time-frequency analysis. The constructed sequential algorithm was able to reduce the total calculation time, and the error was reduced when compared to other typical algorithms.

Recently, mechanical products have become more complicated and many suppliers participate to complete a product. In such situation, it is important to predict the integrated performance of the product with each components. However, prediction of noise and vibration is difficult because vibration characteristics of each component, such as natural frequencies, change when a component is installed into main structure. Then authors have proposed optimized design method for extra devices on a mechanical product; utilizing transfer function synthesis method to predict vibration characteristics of a mechanical product when a device, such as a damper, is installed. For initial approach of the study, this paper describes vibration response prediction of a beam when an additional damper is attached to main structure by transfer function synthesis method. Formulation of transfer function synthesis method is described at beginning. To simplify the discussion, only 2 degree of freedom (1 translation and 1 rotation) is considered in the model, and prediction accuracy is examined quantitatively. Specifically, vibration response at evaluation point, which is separated from both excitation point and damper attachment point, is estimated only with transfer function of substructures: The beam and damper themselves. The predicted values are compared with the result of the full-structure direct approach. As a result, predicted response of the transfer function synthesis method with 2 degrees of freedom agreed well with the response of the full structure direct approach, while predicted response of the transfer function synthesis method with 1 degrees of freedom did not match with measured response at some resonance frequency. It is confirmed that the prediction using transfer function synthesis method is adequately valid and the accuracy of transfer function synthesis method is influenced by utilized degrees of freedom.

In engineering education, in order to develop student’s ability on discovering solutions for advanced engineering problems, it is necessary to have a numerical computing environment that can set mathematical expressions freely and can perform multiphysics analysis. In this paper, we will introduce the function of COMSOL Multiphysics on setting the initial value and boundary value problems for partial differential equations and its coupling with given special field analysis. The possibility of the software as an engineering educational tool is also discussed. Especially with the possibility for constructing easy-to-use applications based on the simulation model, and the function of sending report of the computation via email, inserting PDF document in the application interface, reading experimental data, etc., all these new tools provide wide range of new possibilities for the engineering education.

Many of the machine elements that make up the machine are standardized by JIS, so it is important to master the types and functions of machine elements at the design stage. In the mechanical design lesson, we will newly learn not only the strength calculation, the dimension determination and the mechanical drawing but also the mechanical elements. There is no actual feeling concerning the size, shape, material, weight, etc. of the new mechanical element. Therefore, it can not be realized to compare with the actual one, so it was difficult to understand contents of the lesson. In this class, students' understanding has improved by teaching new machine elements using manufacturing.

This paper reported on the miniaturization method of spectrometer using a plasmonic near infrared (NIR) photodetector. The spectrometer changes the incident angle of light by resonating the MEMS (Micro Electro Mechanical Systems) cantilever. Surface Plasmon Resonance (SPR) occurs when both the wavelength and the angle of incidence of the illumination light matches the resonant condition of surface plasmon. Since SPR excites the electrons in the metal film, the SPR can be measured as photocurrent using Schottky barrier between Au and n-type Si. The relationship between the responsivity and the angle of incidence contains the spectrum information of the incident light. To calculate responsivity for calibration the device before measurement, time responses of photocurrent from SPR was measured during the vibration of the cantilever. We measured the time responses of photocurrent and confirmed they were dependent on the incident wavelength, and coherent to the SPR theory.

In this study, we evaluated the suction forces focusing on suction cup area of circler micro suction cup arrays and elliptical micro suction cup arrays. We fabricated two kinds of both micro suction cup arrays and measured the suction forces in vertical and two parallel directions to the suction surface. It was confirmed that the suction forces in the three directions increased with the increase of the suction cup area. The linearly approximated gradients of the suction forces to the suction cup area were almost same in vertical direction and the long axis direction both circular and elliptical micro suction cup arrays whereas that of elliptical micro suction cup array in the short axis direction was smaller than that of circular micro suction cup array. This result means that by changing the cup shape from circular to elliptical keeping the cup area same, only the characteristics of suction force in the parallel direction to the suction surface can be change.

We measured deformation of convex microstructures on a flexible integration substrate for roll-type stamping transfer. Roll-type stamping transfer is an integration method for small parts, which are made on another substrate, onto a flexible integration substrate. It has been reported that shear stress between two rollers causes misalignment of the small parts. In our previous study, we showed that we could decrease the shear stress on small parts and achieve high positioning accuracy of small parts by using convex microstructures on a surface of a flexible integration substrate. It is, however, necessary to evaluate the deformation of convex microstructures in order to enable the design of the dimensions of convex microstructures for high positioning accuracy. In this study, we applied shear stress on convex microstructures and measured the deformation of convex microstructures Δx_con. We theoretically designed length l and diameter d of the cylindrical convex microstructures and fabricated twelve types of cylindrical convex microstructures that have deformation parameter l³/d² ranging from 2.5 μm to 88.6 μm. As a result, we showed that Δx_con has a larger value according to increase of l³/d². Therefore, we can use l³/d² as a design parameter of convex microstructures for roll-type stamping transfer with high positioning accuracy.

This paper reports observation and classification of nanoparticle chain formation using dielectrophoresis according to applied voltage. When non-uniform electric field is applied on nanoparticles in medium, the nanoparticles are trapped on edges of electrodes by dielectrophoresis, then nano- or micro-structures such as nanoparticle chains are formed. However, it varies according to the condition of the formation the way nanoparticle chain forms. For example, some research groups reported that the form of the nanoparticle chain is changed by frequency of the applied voltage. In this paper, we especially observed and classified nanoparticle chain formation with various applied voltage. Observations were conducted with gold electrodes, the electrodes gap of 10 μm and electrode width of 25 μm. Electrodes were covered with 150-nm-diameter gold nanoparticle solution, and applied voltage to the electrodes was changed from 5 V to 40 V. As a result, three-type forms of nanoparticle chain, tree-like form, middle form and bulk form, were observed. Tree-like form is the form that nanoparticle chain is formed straightly, and bulk form is the form that nanoparticle chain is formed isotopically. Middle form is the form in which the properties of both tree-like form and bulk form are observed. Tree-like forms were mainly observed under 20 V, whereas bulk forms were mainly observed over 20 V. Applied power also increased as applied voltage increased, therefore we considered that applied power made nanoparticle chain melt. Melting of nanoparticle chain was observed over 17 mW in applied power.

We here propose a method of inclined rotated ultraviolet (UV) lithography via a rotating prism. In previous studies, the inclined rotated UV lithography has been performed by rotating an inclined mask and wafer. Three-dimensional micro structure can be fabricated by inclined rotated UV lithography; however, this method is not suitable for liquid type UV cured material. Our method is designed for liquid type material because the target wafer does not need to move during exposure. The proposed UV exposure system is composed of a quartz prism, a hollow turntable driving by a motor and conventional mask aligner. Since a prism makes UV light ray bend, the base angle of the prism determines the inclined angle of UV light. Thus, we can control the inclined angle of the UV light by changing the base angle of the prism. In this study, we developed a proto type UV exposure system using a 30 mm ×30 mm rotating prism. The prisms with base angles of 17.5°, 30°, 45°, and 60° were used. The rotational speed was approximately 140 rpm by an AC motor. Finally, it was demonstrated that polyethylene glycol diacrylate (PEGDA) microneedles was uniformly fabricated in 1 inch wafer using the developed UV exposure system.

This paper subscribes micro suction-controller array (MISCA) for enhancing robotic manipulation by humanoid robot hands. MISCA, whose dimension is approximately 10 mm × 20 mm × 5 mm, is composed of a PDMS (poly-dimethylsiloxane) microchannel layer and a suction cup layer and filled by working fluid. We confirmed that MISCA showed approximately 50 kPa suction pressure when the working fluid was drawn by a syringe pump. We believe that this small suction system with MISCA could be integrated into robot hands for enhancing manipulation ability.

In nature, Paramecium is moving by surface cilia. Human respiratory tract cells have cilia. Cilia eliminate foreign matter.From these facts, it is thought that cilia can be used as a microactuator. The pNIPAAm(N-Isopropylacrylamide) gel which is heat-responsive gel attracts attention as gel cause a volume change outside stimulation by temperature change and light and ph change. The hybrid structure consists of cilia structure SU-8 and a thermoresponsive gel. In conventional study changed whole gel. In this study, we control only one point of gel. The purpose of this study is to dynamically control the hybrid structure. Gel is controlled with a microheater array. We obtained a displacement of 806.1 μm at the hybrid structure. We were able to dynamically control any position of the gel. Future study will investigate the miniaturization of the device and the gel change by micro area heating.

In this research, we try to develop a robot which can climb spiral staircase. The robot is required to climb staircase with taking baggage. Our robot has four legs, and each leg has two wheels which the robot can steer. The robot moves its leg up, down, forward and backward in order to climb staircases and rotate its wheels to move on flat place. Moreover, the robot can turn around a pivot to combine these motions at a spiral staircase. In the preceding research, we made a prototype with the mechanism and it could climb straight staircase, but it could not climb spiral staircases. Therefore, we improved the robot to make it be able to climb spiral staircase. Because we changed the mechanism of leg’s moving up and down, the robot became smaller and lighter. In fact, we designed a new robot which is fifteen kilograms lighter than the old one. In addition, we simulated the robot’s climbing staircases using Gazebo in order to verify if the robot can climb them. According to the results of climbing simulation, we found that the robot can climb spiral staircase, and climbing with CT method is faster than climbing with MPT method. In this paper, we report the mechanism of the robot and the way of climbing spiral staircase.

In recent years, a market of service robot is increasing. And a lot of people expect that supports housework robot in a house will be developed. But most current home service robots can do one task only. However housework has many kinds of tasks. So it is the best that one robot can many kinds of housework's tasks. In this research, we focus on the laundry work as one of the housework and we develop a home service robot with dual-arm to help wash the entire work. We study removing laundries from a washing tub as the first step. In this paper, we developed a right arm of the home service robot and simulate removing laundries from the tub. The home service robot had body which has 2 joints and left arm which has 5 joints. New one get right arm which has 7 joints. We inspect whether new arm can remove laundries from the washing tub and hand it to left arm. Right arm must be able to do 4 things for removing laundries. 1^st, the arm can insert in a wash tub. 2^nd, it can reach to bottom of the tub. 3^rd, it can reach to around bottom. 4^th, it can hand laundries to left arm. By simulation, we can prove that the right arm can remove laundries from the washing tub. Therefore we can develop a right arm and simulate removing laundries from the tub.