FIB-CVD is a key technology for fabricating three-dimensional structures. Two kinds of bio nano-tools were developed for subcellular manipulations and analysis. The first was a bio nano-injector, which is a very useful tool because the shape and size of its tip can be freely designed for various functions in local areas. We also fabricated a filtering tool with a nano-net structure on a glass capillary to capture subcellular organells.
This paper describes research topics on nanobio technology. Biomolecular motors are useful as nanobioactuators for the future biohybrid MEMS. Membrane protein chips are important for the highly sensitive, high throughput screening of drugs and environmental chemicals. Here I report these two topics with the recent microfluidic technology.
The latest synchrotron radiation facilities, the third generation light sources such as SPring-8, enter in a matured phase. The brightness of the synchrotron radiation has been increased by undulators and low emittance storage rings. The development of ERL (Energy Recovery LINAC) follows the way of further decreasing the electron beam emittance and generates much shorter radiation pulses. The other direction is moving from spontaneous radiation to stimulated emission, that is an FEL (Free Electron Laser). Different from conventional lasers, there is no constraint of light wavelengths in the FEL due to atomic or molecular energy levels. Therefore the FEL is a prospective candidate for an X-ray coherent light source. Currently two X-ray FELs are under construction in Japan and U.S., and X-ray coherent light will be available within two or three years. In this report, principles of synchrotron radiation and FEL are briefly summarized including the topics of next generation FEL sources.
A micro liquid rotor that operates with surface acoustic waves (SAWs) was proposed and fabricated. The liquid rotor has two interdigital transducers (IDTs) that generate SAWs, in order to increase efficiency of rotating the liquid. The IDTs were fabricated by patterning Al/Cr on a LiNbO3 substrate. As the IDT parameters, we used a stripline pitch of 200μm, 20 stripline pairs and an aperture size of 2mm. A liquid pool in the rotor is a round shape of 4mm diameter, and its depth is 200μm. A sidewall of the liquid pool was made of SU-8 on the substrate. As characteristics of the liquid rotor, we investigated relationships between electric power applied to the IDTs and angular velocity of the liquid or its temperature. For applying the electric power to the IDT, we used a burst voltage waveform that has sine frequency of 19.6MHz and duty ratio of 10%. Through experimentation we showed that the angular velocity or the temperature increase with increasing the electric power. In addition, we also found that a response time of the angular velocity is faster than that of temperature of the liquid. When the fabricated liquid rotor was applied electric power of 2W, the liquid of 5μl rotated at 330rad/s (3,100rpm) and its temperature reached 65°C.
We have investigated the Au-SrTiO3(100) interface as a function of the Au evaporation using the photoemission spectroscopy. In the valence band of SrTiO3, the broad state originating from O 2p electrons and a state from Ti 3d electrons were observed between 3-9 eV and at 1 eV below the Fermi level (EF), respectively. With increasing the Au evaporation, the decrease in intensity of the state at 1 eV was observed. In the Ti 3p core-level, the decrease of the Ti3+ states was observed after Au evaporation. These results indicate that the electrons transfer from the Ti3+ states of the SrTiO3(100) surface to the evaporated Au. In addition, with increasing the Au evaporation, the larger shift of the peak in the Au 4f core-level to lower binding energy side was clearly observed as compared to that of the Sr 4p, O 2s, Ti 3p, and Sr 3d core-levels. Based on the results of the photoemission spectroscopy of the valence band and core-levels, we will discuss the electronic structures of the Au-SrTiO3(100) interface.
We report results of the study on natural oxidation of Cu3Au(110) with high-resolution x-ray photoemission spectroscopy in conjunction with synchrotron radiation. The clean surface of Cu3Au(110) is terminated with 50% Au and 50% Cu atoms. After the natural oxidation in the air, Cu atoms segregate on the surface and produces the Cu-oxide. As a result, Au atoms move to the bulk. Au atoms below the oxide reduce the diffusion of O atoms further into bulk and limit the oxide thickness. From the face dependence of natural oxidation, the diffusion of Cu atoms also contribute to the oxide formation.
Many middle aged and old persons take periodontal diseases that mainly cause teeth loss and result in some systemic diseases. The prevention of periodontal diseases is very important for oral and systemic health, but the present diagnostic examination is not fully objective and suitable. To diagnose periodontal diseases exactly, some biomarkers shown inflammation, tissue degradation and bone resorption, in gingival crevicular fluid (GCF) and saliva are known. We demonstrated that GCF levels of calprotectin, inflammation-related protein, and carboxy-terminal propeptide of type I procollagen, bone metabolism-related protein, were associated with clinical condition of periodontal diseases, and suggested that these proteins may be useful biomarkers for periodontal diseases. Recently, determinations of genes and proteins by using microdevices are studied for diagnosis of some diseases. We detected calprotectin protein by chemiluminescent immunoassay on a microchip and showed the possibility of specific and quantitative detection of calprotectin in a very small amount of GCF. To determine plural markers in GCF by using microdevices contributes to develop accurate, objective diagnostic system of periodontal diseases.
We have proposed a numerical methodology termed pixel mapping (PM) method on the basis of crystallography. The PM method can characterize various defects in 24 prototypes cubic crystals listed in the Strukturbericht database. It identifies point defects, linear defects, planar defects (including antiphase domains in compound crystals), also structure change (including amorphization). The long-range order (LRO) parameter has been defined as a set of LRO components for each prototype. Further advantage of the PM method results from the coarse-grained viewpoint, which allows us to specify the Miller index of a planar defect with areal density or crystallographic direction of a linear defect. We found a tetrahedral antisite cluster, (CSi)SiC)4, in 3C-SiC due to ion irradiation. The bonding directions from central to surrounding atoms were all <111> directions. We examined the reason why such cluster was formed. Whenever this cluster was formed, the collapse of LRO preceded. Then clusters emerged remarkably associated with many complexes of antisites-vacancy pairs.
Poly-tetrafluoroethylene (PTFE) is very attractive material for various fields, because of its chemical resistance, heat resistance, inslation property and hydrophobic property, etc. However, it is difficult to fabricate PTFE microstructures with conventional techniques such as semiconductor process or micro machining. We had succeed in the fabrication of high-aspect-ratio micro fluidics parts of PTFE by direct in-vacuum photo-etching using synchrotron radiation (SR) with energy from 2 to 12keV. This paper reports analyzed mechanisme of PTFE microfabrication process and discovered new processing characteristic of PTFE.
An extreme ultraviolet source using laser-produced lithium plasma has been studied. The authors obtained an enhancement of extreme ultraviolet conversion efficiency by a factor of about 2 with recombination wall. In a planar lithium target experiment, the maximum conversion efficiency of 2.3% was achieved by using pulsed 2ω YAG laser irradiation. These results suggest that a Li target is a reasonable candidate for the EUV lithography source.
A high-brightness electron source of ultra-small emittance and high-average current is one of the most important components for next-generation light sources based on an energy-recovery linac (ERL). Such a high-brightness electron source can be realized by a DC photo-cathode gun driven by laser pulses tailored in temporal and spatial dimensions. We propose a novel photocathode based on a quantum cascade laser (QCL). Since ultrafast response of photo-electron emission from the QCL is compatible with tailored laser pulses, it is a candidate for the electron source for ERLs.
Microdevices have recently been developed by various micromachining technologies such as laser cutting, lithography, etc. PTFE is widely used as a microwave and millimeter-wave material. However, it is known that PTFE is too difficult to process with high precision by conventional machining, or even by laser cutting or electrical discharge machining. It has been reported that PTFE microstructures can be fabricated by direct exposure to synchrotron radiation. In this paper, the SR direct etching of PTFE is introduced and a trial fabrication of millimeter-wave PTFE-filled waveguide by sputter deposition of metal is attempted.
The neural activity of dissociated cultures of mouse cerebral cortical neurons was measured with a conductive polymer microelectrode array. Each electrode was electrochemically polymerized from (3,4-ethylenedioxythiophene)- poly(styrenesulfonate) and ethylenedioxythiophene on indium tin oxide electrodes. The spike activity of the cortical neurons was measured with the conducting polymer MEA and spike train cross-correlograms were calculated to predict the type of synaptic connection. Both excitatory and inhibitory synaptic connections were identified after 6-8 days in vitro. These results show that it is possible to determine the interaction between excitatory and inhibitory neurons in relation to information processing with this new polymer electrode.
The importance of the micro fluidics systems for high throughput post-genome analysis has increasing more and more. We proposed and fabricated an integrated 6 microchip capillary electrophoresis units in a small area of 30mm×30mm for high throughput DNA analysis. The design of the structure was performed using fluid dynamics of electrophoresis simulation to improve DNA separation resolution. As a result, narrow width of micro channel at the corner was adapted. As for the simple fabrication method of the microchip, we developed the PMMA structure of micro fluid channel using lithography, molding and fusion bonding techniques. It was demonstrated that the proposed integrated structure of micro channels results in a good performance of the on-chip DNA separation in a small one unit area of 9mm×9mm.
A novel micromixer is proposed, fabricated and verified. The new concept of the micromixere is to cross-link the many capillaries in three-dimensional structure. The characteristic flow behaviors are simulated by using computational fluid dynamics(CFD) software “FLUENT”. The results of the CFD shows unique mixing behavior in three-dimensionally cross-linked capillaries. The mixing performance of the micromixer is strongly influenced by controlling the three-dimensional crossing condition. The micromixer is fabricated by means of deep X-ray lithography with multi step exposure. The cross-linked capillary structures are successfully fabricated with controlled cross-link conditions. The performance of micromixer is evaluated by using a kind of enzyme reaction. By comparing mixture, mixed with cross-linked fluid filter and fluid filter without cross-linked capillaries, we found out the speeding up of the reaction by using new micromixer.
Microchip electrophoresis has recently attracted much attention in the field of nuclear acid analysis due to its high efficiency, ease of operation, low consumption of samples and reagents, and relatively low costs. In addition, the analysis has expanded to an analytical field like not only the analysis of DNA but also the analysis of RNA, the protein, the sugar chain, and the cellular function, etc. In this report, we showed that high-performance monitoring systems for human blood glucose levels and α-amylase activity in human plasma using microchip electrophoresis.
A new cluster time-of-flight secondary ion mass spectrometry (TOF-SIMS) was developed using a size-selected gas cluster ion as a projectile. Since a large gas cluster ion can generate many low-energy constituent atoms in a collision with the surface, it causes multiple and ultra low energy sputtering. The mean kinetic energy of constituent atoms is provided by dividing the acceleration energy of the gas cluster ion by the number of constituent atoms. Therefore, the sputtering can be controlled to minimize the decomposition of sample molecules and substrate material by precisely adjusting the number of constituent atoms (the cluster size) and/or acceleration energy of the gas cluster ion. The cluster size was selected by the time-of-flight method using two ion deflectors attached along the ion-beam line. A high resolution of 11.7 was achieved for the cluster size/size width (m/Δm) of Ar-cluster ions. SIMS spectra of polymethyl methacrylate (PMMA) was measured using the size-selected gas cluster SIMS machine. As increasing the cluster size, large fragment ions emitted from PMMA were enhanced. This result suggested that the decomposition of the polymer structure was suppressed by the larger cluster ion projectile which decreased the kinetic energy per constituent atom of a cluster ion.
The Al(111) surface has been directly nitrided by supersonic N2 molecular beams at 473 K. A translational kinetic energy threshold of the nitridation was 1.8 eV. A nitrogen uptake curve obtained at the translational energy of 2.0 eV showed a linear profile with the nitrogen dose indicating non-protective layer formation. Al-2p photoemission spectra were involved a merely-shifted shoulder structure in the higher binding energy side so that sub-nitride components were included in the AlN overlayer.
A novel oscillation condition of quartz oscillating circuit with 622 MHz AT-Cut HFF-Xtal (=High Frequency Fundamental-crystal) oscillator is established. A circuit analysis is performed by combining a shunt capacitance (C0) with a negative resistance (-Rci) and a combination capacitance (Ct). A load resistance (RL) is obtained by combining C0 with -Rci. A maximum load resistance (RLmax) is relative to the value of combination capacitance (Ct).
Feature extraction for mental fatigue and relaxation states is helpful to understand the mechanisms of mental fatigue and search effective relaxation technique in sustained work environments. Experiment data of human states are often affected by external and internal factors, which increase the difficulties to extract common features. The aim of this study is to explore appropriate methods to eliminate individual difference and enhance common features. Mental fatigue and relaxation experiments are executed on 12 subjects. An integrated and evaluation system is proposed, which consists of subjective evaluation (visual analogue scale), calculation performance and neurophysiological signals especially EEG signals. With consideration of individual difference, the common features of multi-estimators testify the effectiveness of relaxation in sustained mental work. Relaxation technique can be practically applied to prevent accumulation of mental fatigue and keep mental health. The proposed feature extraction methods are widely applicable to obtain common features and release the restriction for subjection selection and experiment design.
Surface electromyogram (EMG) from elbow, wrist and hand has been widely used as an input of multifunction prostheses for many years. However, for patients with high-level limb deficiencies, muscle activities in upper-limbs are not strong enough to be used as control signals. In this paper, EMG from lower-limbs is acquired and applied to drive a meal assistance robot. An onset detection method with adaptive threshold based on EMG power is proposed to recognize different muscle contractions. Predefined control commands are output by finite state machine (FSM), and applied to operate the robot. The performance of EMG control is compared with joystick control by both objective and subjective indices. The results show that FSM provides the user with an easy-performing control strategy, which successfully operates robots with complicated control commands by limited muscle motions. The high accuracy and comfortableness of the EMG-control meal assistance robot make it feasible for users with upper limbs motor disabilities.
In many engineering fields, distance to target is very important information. As a typical method, distance is estimated by measuring time delay between transmitted and reflected waves. However, it is difficult to estimate short distance by a method like this. On the other hand, a method using standing wave to measure short distances has been known in the field of microwave radar. We have applied this method to distance estimation using audible sound and shown the validity of that through our simulations and experiments. In this paper, we present the prototype system for distance estimation in which this method is implemented, and evaluate the performance of this system by experiments in actual sound field.
For design of the autonomous robot, action learning ability based on the subjective feeling pain is an important issue. In our previous researches, artificial superficial pain model caused by impact had been studied and the transmission mechanism focused on the input-output relations was proposed. However, the generation mechanism of the pain has not been considered yet. In this paper, the pain model of slow pain considering the skin dynamics is proposed. It is clarified from the FEM simulations that the strain energy density (SED) caused around the layer is related to the subjective pain level. From the experimental pain caused by quasi-static motion, the proposed pain model is evaluated.
In this paper, we describe the brain activities that are associated with graphic emoticons by using functional MRI (fMRI). We use various types of faces from abstract to photorealistic in computer network applications. A graphics emoticon is an abstract face in communication over computer network. In this research, we created various graphic emoticons for the fMRI study and the graphic emoticons were classified according to friendliness and level of arousal. We investigated the brain activities of participants who were required to evaluate the emotional valence of the graphic emoticons (happy or sad). The experimental results showed that not only the right inferior frontal gyrus and the cingulate gyrus, but also the inferior and middle temporal gyrus and the fusiform gyrus, were found to be activated during the experiment. Forthermore, it is possible that the activation of the right inferior frontal gyrus and the cingulate gyrus is related to the type of abstract face. Since the inferior and middle temporal gyrus were activated, even though the graphic emoticons are static, we may perceive graphic emoticons as dynamic and living agents. Moreover, it is believed that text and graphics emoticons play an important role in enriching communication among users.
Recently, we can be able to get a lot of information easily because information technology has been developed. Therefore, it is thought that the impact to a society by communication of information such as word of mouth has been growing. In this paper, we propose a model of emergence of opinion leader based on word of mouth in artificial stock market. Moreover, the process of emergence of opinion leader and impact to stock prices by opinion leader are verified by simulation.
The key in stock trading model is to take the right actions for trading at the right time, primarily based on the accurate forecast of future stock trends. Since an effective trading with given information of stock prices needs an intelligent strategy for the decision making, we applied Genetic Network Programming (GNP) to creating a stock trading model. In this paper, we propose a new method called Real Time Updating Genetic Network Programming (RTU-GNP) for adapting to the change of stock prices. There are three important points in this paper: First, the RTU-GNP method makes a stock trading decision considering both the recommendable information of technical indices and the candlestick charts according to the real time stock prices. Second, we combine RTU-GNP with a Sarsa learning algorithm to create the programs efficiently. Also, sub-nodes are introduced in each judgment and processing node to determine appropriate actions (buying/selling) and to select appropriate stock price information depending on the situation. Third, a Real Time Updating system has been firstly introduced in our paper considering the change of the trend of stock prices. The experimental results on the Japanese stock market show that the trading model with the proposed RTU-GNP method outperforms other models without real time updating. We also compared the experimental results using the proposed method with Buy&Hold method to confirm its effectiveness, and it is clarified that the proposed trading model can obtain much higher profits than Buy&Hold method.
In the development of reuse-based software, it is necessary at the beginning to judge the feasibility of the development project including the estimation of a workload, development period, required engineers and skill, development cost such as real dispensation, a developer, and cost volume profit,. Computer assistance is desired for extracting a software module for reuse from existing software and improving the efficiency and accuracy of development estimation work. In this paper, A cooperative estimation assistance system utilizing configuration management technique which visualizes the relationship between software modules of the existing software is proposed. Thus this system supports the estimation in ascertaining of the development range, the total of the workload of the probed software, the allocation of development engineers, and the collaboration in dispersed development environment. Furthermore, this paper describes the application of the proposed method to the prototype of software reuse development, and its evaluation.
In this paper, we propose a method which aims to let people inside a building evacuate when a disaster occurs. Especially, it is very difficult for them to evacuate safely under the situation of blackout which makes servers down. In the proposed method, passive RFID tags are put on walls of the building and each user has a mobile terminal that is battery-powered and equipped with an RFID reader. It identifies evacuation routes by passive RFID tags the user touched. The method identifies safe routes using the movement of people who have evacuated safely. Mobile terminal communication and RFID tags realize to share information of the safe routes with many evacuees. An experiment is conducted to let people evacuate in two routes in an actual building, giving about half of them mobile terminals. We have measured the increment of blood pressure and heart rate of the evacuees before and after the evacuation. In both routes, the increasing rates of the evacuees with the terminal have been smaller than those of evacuees without the terminals. It proves that the proposed method brings assurance to evacuees.
This paper presents a model-based method to design a software platform, called an application common platform for developments of enterprise information systems. This application common platform(ACP) wraps existing reusable software assets to hide their details from application developers and provide domain level application programming interfaces, so that reusability of software assets and productivity of application improve. In this paper, we present a software architecture which organizes applications, ACP, and software assets and illustrate a development process of ACP. Especially, we show design rules to derive ACP design models from application design models and software assets design models. We also define metrics of reusability and productivity and evaluate the proposed method through real developments of enterprise information systems. As a result, the proposed method reduced 20% of development cost compared to estimation cost.
Public key cryptosystems such as RSA often require modular exponentiations. Modular exponentiations are performed by repeated modulo multiplications. We have proposed the high-speed modulo multiplier suitable for repeated operations. In this letter, we apply the modulo multiplier to modular exponentiation. Though we require one division at the end of modular exponentiation by use of the modulo multiplier, the whole delay time does not almost increase because the delay time of division is very shorter than that of modular exponentiation. Finally, by using PARHTENON, which is the design system for VLSI, we show the modular exponentiation circuit using our modulo multiplier is very fast as well as the modulo multiplier itself.