We proposed a simple method in order to fabricate high aspect ratio and high density microneedle arrays using backside exposure. These microneedle arrays are needed in fabricating perforated glucose responsive fluorescent hydrogel block. Three dimensional printing is one of the easiest way to fabricate microneedle arrays. However, three dimensional printing can fabricate minimum 200 μm diameter microneedle. In this research, we fabricated about 50 μm diameter and 1 mm height microneedle arrays using backside exposure method. We believe that this method is useful for fabricating high aspect ratio and high density microneedle arrays and also contribute in fabricating perforated hydrogel block.

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The performance of parylene E as a VOC sensing material has been benchmarked through a series of measurement of the dynamic/equilibrium capacitance responses in fringe-field type chemicapacitive sensors. The capacitance change over toluene and ethanol vapor has been obtained for different concentrations and different polymers. It is shown that parylene E has a unique gas-sensing nature with a high sensitivity to non-polar VOC and a high selectivity against polar VOC.

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With a motivation for developing oxy-hydroxyapatite (OHA) ceramic-electret applicable to a vibration energy harvesting system, the poling characteristics of OHA ceramics were investigated in terms of microstructure using thermally stimulated depolarization current (TSDC). OHA is a hydroxyapatite (Ca₁₀(PO₄)6(OH)₂)-derivative material, in which the OH- ions are partially substituted by O^2- ions and vacancies (Ca₁₀(PO₄)6(OH)_2-xO_x/2). A vibration electret generator using 14-mm diameter OHA ceramic electret was prototyped with patterned electrodes, which serve as the electrostatic shield on the surfaces. The relationship between surface potential and the pattern width of the gold electrodes was experimentally revealed, and the power generation characteristics were obtained.

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With breaking up of a stretching liquid bridge, micro droplet is generated near the center of the gap of separated liquid drops. We investigated the effects of the volume and the surface tension of liquid bridge on the size of generated micro droplet. Water, nonane and silicon oil are used as test liquid in the experiment because these three liquids have approximately equal kinematic viscosity. In the experiment using water which has higher surface tension than ones of other two liquids, the diameters of generated droplets are smaller than the diameters of these two liquids. At all experiment, dispersion of the size of generated droplet is up to about 6 µm and is nearly equal to reading error. The diameter of generated droplet increases linearly as the volume of liquid bridge increases.

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The fracture by the nano-scale contact should be investigated to understand the mechanism of the advanced mechanical processing. Using a combination of the scanning probe microscope (SPM) with possible high space resolution of nano-scale and the acoustic emission (AE) with high sensitivity for fracture is one of the possible way of investigating the fracture mechanism. When using the SPM, the AE signal might be detected with receiving the AE wave by the piezoelectric scanner of the SPM receiving the AE wave, where by the piezoelectric effect the electric signal due to the AE wave is superimposed on the scan signal. Based on that, in this study, a novel method to detect AE signal from the scan signal is proposed. By a simple experiment using the AE wave simulator, we confirm the AE signal could be detected by the piezoelectric scanner of the SPM.

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We investigated the basic rules of self-organization using an outer-totalistic Cellular Automaton (CA). In these models, the cell state is determined by summing the states of neighboring cells; Conway’s Game of Life is an example. This study used a short-range and long-range summation of the states of cells around the focal cell. These resemble reaction-diffusion (RD) equations, in which self-organizing behavior emerges from interactions between an activating factor and an inhibiting factor. At the same time, Game of Life-type rules, in which a cell cannot survive when adjoined by too many or too few living cells, were applied. Our model was able to mimic patterns characteristic of biological cells, including movement, growth, and reproduction. This result suggests the possibility to control self-organized patterns. Our model can also be applied to the control of engineering systems such as multi-robot swarms and self-assembling nano-robots.

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This paper reports visualization results of immiscible multi-phase fluid flow in microchannel for a synthesis of gold nanoparticles dispersion in an organic solvent by a glass microfluidic device. Brust–Schiffrin synthesis method with complex process can prepare gold nanoparticles dispersion in toluene. However, since a flow control of the immiscible multi-phase fluid consisting of toluene and aqueous solution is required for the synthesis using microfluidics device, the visualization of fluid in the microchannel was conducted by using red and blue ink aqueous solutions as a substitute for gold ion and reducing agent. From the experimental results, we confirmed that the fluid showed a parallel flow over flow rate of 0.25mL/min and a slug flow below the flow rate of 0.08mL/min.

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In this study, we investigated micro-scale lubrication properties of the nanostripe surface using AFM (atomic force microscope). The nanostripe surface is a kind of surface texturing, which has micro/nano-scale grooves consisting of multilayer films of two kinds of metal materials fabricated on silicon substrate. we rubbed two kinds of nanostripe surfaces, i.e., cross and herringbone patterns, composed of Ag-Cu using a metal cantilever having BK7 convex lens instead of a probe. Before friction test, lubricant oil (Hexadecane) was applied on the substrate using a spin coater. As a result, on the cross pattern, the measured friction force showed locally different values according to mutual sliding direction against grooves. On the herringbone pattern, the measured friction force was reduced at the apex of herringbone grooves. The effect of herringbone geometry became more pronounced at the higher scanning speed.

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This paper presents the effect of lattice constant change on the friction force using the stress-concentrating micro device. We designed micro devices that generate stress concentration by vending. These were fabricated on SOI (silicon on insulator) wafer by MEMS (microelectro-mechanical systems) technology. We measured the frictional force using AFM (atomic force microscope) under heating vacuum condition by changing the applied voltage of this device. As a result, we observed the frictional force distribution changed with voltage. The maximum change rate of frictional force was 10% but we couldn’t confirm the clear relationship between lattice constant and the friction force．We consider the causes are small stress concentration due to over developing and natural Si oxide film of the surface of the cantilever and device. Although we couldn’t clarify the relationship, we showed useful possibility and issues of this device.

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Micro-lenses of small mechanical elements are used for image pickup devices and displays, and finer lenses are required to improve their performance. Several researches have been conducted on liquid driven micro-lenses to provide variable focus and various lens functions. However, it is anticipated that there is a limit to miniaturization of mechanical elements when mechanical elements are used under hydraulically powered. Therefore, in this research, we aim to develop compact lens with various focal length combining our small and simple micro EHD pump and micro-lenses which we have developed in the past. We found that it was possible to control the focal point of the lens with working solution of the micro EHD pump. In the future, we would integrate micro-lenses with the micro EHD pumps.

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We propose design method of stretchable metal wires which satisfy required maximum elongation using elongation stiffness of the substrate and the wave shape of the wires. We used two kind of wire shape, elliptic arc curve and sinusoidal curve. In both shapes, tensile tests showed increased stretchability by the increased stiffness of the substrate. The wires with the larger amplitudes showed better stretchability, but on the other hands, the resistance increases as the amplitude increased. These results indicated that we can design stretchable metal wires with the lower resistance even under the condition where the minimum stretchability and the maximum stiffness are given.

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We have proposed a simultaneous measurement method for viscosity and density of liquid with an oscillating flow in a micro channel. A developed viscosity & density meter was consisted of a straight micro channel, a chamber opened to the atmosphere, and a chamber with a diaphragm. The volumetric vibration of the chamber induced by a diaphragm with a piezoelectric actuator produced an oscillating flow in the channel. The viscosity and density were calculated by the pressure amplitude in the chamber and the phase difference between the periodic motion of the diaphragm and the time change of the pressure. Water and aqueous glycerin solutions were used as the test sample. As a result, measured viscosity was less than reference value, and density was four times as large as reference value.

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We propose microfluidic modules as connectable platforms to form coaxial microfluidic devices for formation of monodisperse droplets and hydrogel fibers according to the intended use (Fig. 1). By integration of the microfluidic modules, we succeeded in preparation of variable designed coaxial microfluidic devices: axisymmetric flow-focusing device (AFFD) and coaxial laminar-flow device (CLFD). Using the AFFD and the CLFD, we achieved formation of monodisperse water-in-oil (W/O) and W/O/W droplets and multiple layered hydrogel fibers including cell-laden microfibers, respectively. Therefore, we believe that the microfluidic modules will be useful tools for researchers in various fields in biology and chemistry to prepare coaxial microfluidic devices without manufacturing techniques of coaxial microfluidic devices.

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In order to realize a self-soldering material for joint use, we investigated the exothermic reactivity of developed composite materials made by mixing Al/Ni multilayer powder and solder paste. Composite samples made of different composition of Sn paste (0, 25, 50 and 100 wt%) and different particle size of Al/Ni multilayer powder (~75 and 250~500 µm) were prepared for reacting test using electric spark. Experimental results of 0~50 wt% Sn paste with ~75μm Al/Ni samples show violently reaction with enormous heat and melting Sn paste. In conclusion, this soldering heat source that be able to melt the Sn powder by own exothermic heat is created. As future works, we will caryy out point bonded test for metal wire to investigate bonded characteristics of self –soldering material.

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In this study, we conducted numerical analysis in the diffuser/nozzle based valveless micropump to understand an effect of the asymmetric characteristics of pressure loss in the micropump channel on pump characteristics. We had been investigated relationships that generations of vortices in the diffuser channel is related to the pump characteristics by using visualization of the flow and PIV analysis. However, the relation between the pressure loss of the asymmetric flow channel and the pump characteristics is not investigated. Therefore, we calculate the pump performance of the valveless micro pump using numerical analysis and investigate the relationship between the driving frequency, the flow velocity amplitude, and the pressure loss due to the unsteady flow, which affect the pump performance.

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With increasing public interest in alternative energy sources, research and development groups are seeking thermoelectric (TE) applications with a low environmental load. Since the TE efficiency of bulk Si is quite low, nanoscale modifications are required to increase ZT and thus its potential use in commercial TE devices. However, many modifications rely on expensive lithography techniques [1] which cannot yield an affordable commercialized TE device. This work demonstrates a low-cost, method for increasing the ZT value of doped single-Si membranes over a large area by the deposition of Al thin films on the Si surface.

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The polymer electrolyte fuel cell (PEFC) is a clean and high efficiency power generation system. However, there are still several issues to be solved commonly used. One of the most serious issues accumulated in a channel, a catalyst layer, a gas diffusion layer lead to PEFC performance degradation because too much liquid water disturbs the reactant gas to the reaction site. In addition, the inside of PEFC is complex system because of two-phase flow of liquid water and vapor. So, we need to focus on the vapor transport as well as liquid water to reveal water transport inside the cell. There are some approaches to comprehend the RH inside PEFCs. However, the methods of these reports could not measure unsteady humidity at a channel. So, we have developed thin film humidity sensor (TFHS) using micro-electro-mechanical-systems (MEMS) technology for unsteady measurements of humidity distribution in a cathode channel.

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The Sliver-Alumina-cermet was fabricated by using metal organic decomposition method (MOD) in large area by low costs. The metal organic solvent with silver nano-particles was spin coated on the glass film with a deposited silver thin film, and heated up at 100ºC by a hot plate. The spectral normal-hemispherical reflectance of the samples with different silver particles concentration were measured by FT-IR. The spectral normal absorptance was calculated from the measured spectral reflectance. The absorptance was high in visible range, and the absorptance was low in infrared range. The figure of merit (FOM) of the cermet was calculated to be 0.59.

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Alcohols play an important role in coolants and other applications in industry, and a detailed understanding of the mechanisms of their thermal conductivity would be useful in the design of new liquids. In this study, the influence on thermal conductivity of the placement and number of hydroxyl groups situated on a 3-carbon (propane) chain is investigated using equilibrium molecular dynamics simulation. The study shows that short-range pairwise interaction plays a significant role in thermal conduction. This pairwise interaction is shown to be dominated by the presence of the hydroxyl groups. While increasing the number of groups is shown to increase their influence on the pairwise thermal conductivity, the choice of location of two groups on the carbon chain is not observed to change their importance for pairwise thermal conductivity.

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We prepared poly(dimethylsiloxane) (PDMS)-based microparts and fabricated hexagonal periodic structures by selfassembly. Periodic structures of PDMS are advantageous for the development of micro-optical devices because of the high transparency of PDMS in a wide range of wavelengths, including visible light. PDMS microparts were fabricated using the combination of photolithography and ultra-violet ozone treatment. The shape of the microparts was hexagonal prism consisting a hole in the center. The side lengths and the height were 10 μm and 8 μm, respectively. Self-assembly was progressed by the coffee-ring effect that flow the microparts toward outside of the suspension droplet that consisted of PDMS microparts and deionized water. A diffraction pattern was observed by laser irradiation to the self-assembled periodic structures. The ring pattern indicates that series of periodic structures were partially formed on the template.

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Understanding of change of a contact area due to a passage of current is significance for design of electric contacts of MEMS devices. In this paper, we investigate the change of contact area experimentally. In the whole experimental process, resistance and force generated around the contact area are measured. Those values are used for the estimation of the contact radius during the experiment. Additionally, the contact radius is optically observed by a microscope. The experiment result shows that the contact area melts and its contact radius increases proportionally with values of electric current. The proportional relation agrees with a theoretical result that authors have presented. This agreement suggests that the theoretical result is universal and applicable for other scale and materials.

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Mixing of minute reagents is one of the common operational elements in integrated microfluidic devices. Although a variety of mixer units have been developed, most of them are designed to use external pumps. In this study, we designed a pumpless micro-mixer for mixing reagents in μL volume. We employed a vibration-induced flow, in which a mean circulating flow around a micro-pillar is induced by giving small circulating vibration to the whole substrate. By employing non-axisymmetric micro-pillar design and switching of circulating direction, we show that stretching and folding of the fluid element, a feature of chaotic advection, can be induced.

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Microstructures with densely assembled TiO₂ nanoparticles were found to be obtained by femtosecond laser irradiation in liquid. Although laser direct fabrication is a powerful tool for fine fabrication, there is strong limitation of materials because adequate absorption is essential for laser interaction. The nanoparticles were effectively assembled around Ag microparticles, precipitated by femtosecond laser reduction, in diluted AgNO₃ solution. The nanoparticle layer was as thick as several micrometer in spite of laser spot diameter of 2 m. Direct laser writing of assembled TiO₂ nanoparticles were successfully performed.

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In this study, we propose a method to detect the shrink/swell behavior of stimuli-responsive hydrogel by a strain sensor using single-walled carbon nanotubes (SWCNT). We fabricated a sensor that detects the deformation of a thin poly-dimethylsiloxane(PDMS) sheet by resistance change of deposited SWCNT. When a stimuli-responsive hydrogel is placed on the sheet of PDMS, the swelling and shrinking responses of the hydrogel can be directly converted to mechanical deformation of the PDMS sheet, resulting in the electrical resistance change of the SWCNT strain sensor. We believe that this approach would be useful as a biochemical sensor for continuous monitoring of biological information.

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This paper reports on a spring-shaped micro coil with low resistance for MRI. The micro coil was fabricated by vacuum evaporation and electroplating of Cu onto the spring-shaped structure made by 3D printer. Since the spring-shaped structure is flexible, we could keep spring-shaped structure of wide pitch to complete large area of Cu wires by vacuum evaporation, that has a low resistance. Furthermore, the micro coil could be compressed with a jig to increase the number of turns per unit length. The resistance of the fabricated spring-shaped micro coil at the frequency of 85.8 MHz was measured at 2.30 Ω. Compared to the resistance of hand-winding coil, the resistance of spring-shaped micro coil decreased by 17 %. The MRI image of the cooking oil was taken by using spring-shaped micro coil at the pixel size of 100×100 μm2 , the SNR was 40.

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In this paper, we newly fabricated a sensor located cantilevers that miniaturized to one fifths size from conventional one, and evaluated its basic characteristics. By the miniaturized cantilever, it became possible to locate cantilevers with high density and an interdigitated array electrode on the chip. The cantilever and the interdigitated array electrode can detect force and light, respectively. As a result, by using the interdigitated array electrode, it was shown that light detection can be performed with higher sensitivity than conventional method. In addition, it was confirmed that the fabricated cantilever has load responsiveness equivalent to conventional cantilever and almost no hysteresis.

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This paper describes a stimuli-responsive microfiber with hierarchically aligned structure from nano-scale to macro-scale. We fabricated the microfiber using a microfluidic device that could make a double coaxial laminar flow. By controlling the flow velocity ratio when fabricating the microfiber, we were able to achieve an anisotropic microfiber where the shrinking ratio of the cross-sectional and axial direction is different. The shrinkage difference presumably comes from the alignment of the molecule inside the microfiber. Furthermore, we bundled the fabricated microfibers and made a macro scale actuator. We confirmed the power that could be produced by the microfiber was about 30 μN/mm². We believe that our microfiber could be applied to actuators for soft robots.

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We propose a bioactuator driven by a chick embryo cardiomyocyte for the investigation of cardiomyocytes as alternatives of rodent cardiomyocytes driven actuator. Chick embryo cardiomyocytes are more accessible than rodent cardiomyocytes in terms of cost and ethics. Here, we cultured chick embryo cardiomyocytes on parylene films and observed that the edges of parylene films were autonomously lifted up and down by the contractile force of cardiomyocytes. Moreover, the frequency of flapping increased in response to the addition of isoproterenol, which promotes contraction of cardiac muscles. This bioactuator would reduce the cost of experiments and thus be expected to promote the study of contractile properties of cardiomyocytes.

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In this paper, we present a perfusion culture system for fiber-shaped tubular tissues mimicking tissues microenvironment. This system can become an alternative method to animal experimentation in drug screening. Important points of mimicking tissue microenvironment are (1) extracellular matrix, (2) 3D culture, (3) perfusability. We fabricated hollow gel fiber using a double coaxial laminar flow microfluidic device, and succeeded in controlling the diameter of hollow of fiber. In addition, we fabricated cell fiber with luminal structure that satisfy the above three requirements by fabricating and culturing hydrogel microfiber with MDCK cells. Using this technique, we aim to apply to drug screening of tissues with luminal structure.

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We report formation of a three-dimensional tissue-like structure achieved by adhesion of massive liposomes. Liposomes generated by the gentle hydration method were assembled by centrifugation in a tapered mold, leading to compact aggregation of the liposomes. The liposomes whose lipids contain biotin molecules adhered each other by avidin-biotin binding by adding solution including avidin molecules. By observing change of morphology of liposomes in contact, we confirmed avidin-biotin binding was effective for liposome adhesion. After centrifugation, we succeeded in collection of a tissue-like structure in millimeter size. This tissue-like structure consisted of liposomes which kept the liposomal structures. Therefore, we believe the proposed method to form the liposome-based tissue-like structure is applicable to various fields including tissue engineering, since liposomes can be utilized for diverse applications from simple biochemical reactor to protocell model.

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A bioprinter, which is capable of depositing cell fibers in a layer-by-layer fashion, is conceived and constructed.

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Fundamental evaluation of the enfold connecting system for simplifying maintenance surgery is presented in this paper. This connector system makes it possible to reduce a surgery time. We designed the connector which doesn’t contact the blood directly because the artificial blood vessel enfolds metal pipe in connector，so the biocompatibility is negligible. We confirmed the blood coagulate protein which form a thrombus at the joint point of the connector with scanning electron microscope. And we also measured a potential of blood coagulation by activated partial thromboplastin time (APTT). We didn’t find the remarkable increase of blood coagulation on the surface of connecting point for 72 hours. And APTT decreased a little in the experiment of a blood circulation system with the connector. However，we can’t conclude the connector causes a blood coagulation from results for 120 minutes，so we need to continue the longtime experiments.

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A film-stack reaction field with a micro-pillars array using a motor stirrer was developed for the high sensitivity and rapid reaction in micro bio-analysis. The effects of the incubation time of a protein (30 s, 5 min, and 10 min) on the fluorescence intensity in Enzyme-linked immunoassays (ELISAs) were investigated using a reaction field with different micro-pillars array dimensions (5-μm, 10-μm and 50-μm gaps between micro pillars). The difference in fluorescence intensity between the well with the reaction field of 50-μm gap for the incubation time of 30 s and the well without the reaction field with for incubation time of 10 min was 6%. The trend of the fluorescence intensity in the gap between micro pillars in the film-stack reaction field was different between the short incubation time and the long incubation time because of different factors related with the biomolecule transport in each incubation times.

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This paper describes a human thrombin DNA aptamer modified acrylamide gel for biochemical sensor. DNA aptamer is single strand DNA that bind to a specific target molecule. As a preparation for fabricating the gel sensor, we fabricated ssDNA modified acrylamide gel. We used fluorescently tagged ssDNA sample solution for testing the reaction selectivity of our fabricated DNA-modified gel. We observed that only the sample of fluorescent ssDNA that has complementary to human thrombin aptamer sequence immobilized in the gel. This result shows that human thrombin aptamer DNA is properly modified into acrylamide polymer chain. We believe that our approach could be effective to construct aptamer-based biochemical hydrogel sensors.

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This paper describes multiple structural color hydrogel array integrated with a microfluidic chip. The microfluidic chip can sense multiple physical/chemical targets (ex. concentration of chemical molcules and temperature) at the same time simply in visible light region with only the color changes of the arrayed stimuli-responsive structural color hydrogels in the top chambers. Sample solution was introduced in the bottom channel and react to the arrayed hydrogel via sandwiched porous membrane. We evaluated our device by measuring ethanol/water concentration and temperature, and confirmed the structural color changes of our sensor without any external equipment. We believe that our sensing device could be applied to a biochemical sensor or microanalytical chip for environmental monitoring sensor and wearable healthcare devices.

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We studied the properties of giant unilamellar liposomes (GUVs) containing hydrogel as a dynamic microcontainer to construct digital microfluidic system that works in the aqueous environment. Here we especially focus on the release of encapsulated molecules. For conventional liposomes, the poration of lipid membrane is led by applying DC pulses. However, the formed pores are rapidly resealed due to the lipid diffusion in the membrane, resulting in the leakage of only a portion of enclosed molecules. We found that hydrogel formed within GUVs stabilizes the transiently formed pores. As a result, almost all the enclosed molecules can be released to the outer environment.

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In this study, we report on a blood pressure pulse wave measurement device with high wearing repeatability. This device has the supplemental part with a concave portion. We improved the wearing repeatability by fitting the ulnar styloid process into the concave portion. We measured the variation of wearing position of the device. The standard deviation of displacements of X-axis and Y-axis decreased 55 % and 60 %. Since the standard deviations of displacements were decreased, we could improve the wearing repeatability. We measured the wearing time for evaluating the usability. The wearing time with the adjusting mechanism and the supplemental part were 63 and 39 seconds. Since the wearing time was decreased 38 %, we could improve the usability of the blood pressure pulse wave measurement device.

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This paper describes an experimental platform to control endothelial tube formation by patterning cells and extracellular matrix (ECM) within 3D lane-shaped microchambers ． We fabricated two types of microchambers: polydimethylsiloxiane (PDMS) microchambers and collagen microchambers with 100-200 µm in width，and cultured HUVEC in those microchambers to observe how the surrounding 3Dmicroenvironments (the dimensions and materials of microchambers) affects to spontaneous tube formation of HUVECs．We found that the formation of tube-like tissue is different in each microchamber: In the PDMS microchambers，the diameter of vascular tissue was controlled by the width of the microchamber．On the other hand，in the collagen microchambers，the dimension of microchambers affected the aspect ratio of vascular tissue．We believe that our culture system could be an useful tool for understanding the tubeformation behavior of endothelial cells and for creating 3D vascular tissue models in vitro．

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Patterning of multiple biomaterials on a large area allows for the realization of high-function devices. This study aims for the development of a pressure microcontact printing technology, which will realize the large area patterning of biomaterials. A pneumatic force enables to apply a uniform pressure to a whole stamp and transfer a pattern on a large area. Our objective is to achieve the uniform patterning of multiple material. This paper reports the fabrication of a three-layer microstamp with an objective pattern. We characterized the printing performance of the stamp after adding a pressure to the stamp.

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Calcium fluoride micro particles are dispersed in polydimethylsiloxane as a novel optical material for ultraviolet optical filter that is transparent for a specified wavelength and diffusor for the other wavelength. The specified wavelength of 259 nm and 278 nm were discovered by selecting PDMS product. The optical properties were investigated and discussed.

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The compact IoT and data science system based on the open source platform (ThingSpeak) was proposed and demonstrated. Easy and powerful data process with Mathematica was combined by developing a triggering daemon of Python and PHP. This system also accelerate the data process speed from the Android terminal on a site. An IoT-like open source cloud computing platform is developed, based on ThingSpeak and focused on optical image and data analysis. Platform that give users the ability to handle the optical image and numerical data and store them in ThingSpeak by remote.

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While the proposed single probe gripper shows promise in picking up an object using strong capillary and surface tension forces, the main challenge has been the smooth release of the object. I'm proposing to Study on micromanipulation using EWOD. By controlling the electrical field imposed on the gripper surface, one can manipulate the contact angle of the liquid bridge and therefore, the meniscus geometry. Modifying the curvature of the meniscus geometry causes the lifting force between the object and the gripper to change. In order to explain the grasping of the object by the effect of the contact angle manipulation, I conducted an experiment in units of mm. As a result, it was possible to separate by the self-weight of the object and the wettability of the surface by operating the contact angle by application of EWOD.

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We proposed a new easy to use Urine Monitor based on cross-selectivity principle, and send the data over WiFi. Our device harvests the urine using the capillarity effect. We monitor the ionic species with conductivity measurement, and evaluate the organic species concentration with absorbance measurement.

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In this study, we have fabricated device on a chip which can eject multiple electrically-induced bubbles at a time. This device has been developed to injection of medicine or genes. Previously developed 3D probe injector has a problem in terms of high-throughput. It was required to increase the amount of reagent to be injected within short time. Therefore, a multiple injector on a chip has been developed in this study. The design parameters have been evaluated in terms of fluidic conditions. Especially the space between the injectors can be effect the trajectory of ejected bubbles by interfering each other. Optimization of the design of the chip provide high efficient and high-throughput injection device for biomedical applications.

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In this study, we propose a new metallization method which is based on the cavitation phenomena and electro-chemical properties of micro-bubbles. First of all, one point metallization experiment was carried out and it was confirmed that the metal is successfully fixed on a substrate. As a result, we confirmed that deposited material was seems to be nickel. Nickel which is initially ionic state in plating solution can be deposited by reduction reaction which is brought by electric charge on the bubble. This technology has possibility to metallize wide range of materials such as paper, polymer, metal and so on, and easy to apply to the 3D printing machine. Precise, robust and simple electrical circuit can be fabricated without any complicated procedures and pre-treatment and which can be contribute to micro-fabrication technology.

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The demand for measurements of fatigue and mental stress in our life, which leads to low tragic accidents, low efficacy, and illness is now becoming bigger in recent years. In order to solve these problems, we fabricated a micro-fabricated eyeglass-shape optical sensors system in our prior work. The fabricated sensors system can detect subject’s blinks by its dye-sensitized photoelectric cells or DSSCs. However, the DSSCs have possibilities to obstruct subject’s line of sight because of its position. The DSSCs are arranged on the center of glass substrate. In this study, we considered optimal placement of DSSCs to detect subject’s blinks without disturbances. It was experimentally revealed that detection sensitivity of blinks depends on the distance between DSSCs and subject’s pupil. We conclude that DSSC should be placed on where it does not disturb user’s visual field and close to user’s eyeball.

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In this study, we fabricated the microelectromechanical systems (MEMS) microphones composed of piezoelectric Pb(Zr,Ti)O₃ (PZT) thin-film bimorphs. To improve the sensitivity of the piezoelectric MEMS microphone, we designed the PZT bimorph cantilevers by using a finite element method (FEM) simulation. The dimensions of the PZT bimorphs are 1000 μm in width and 280 μm in length. The two layers of 1-μm-thick PZT thin films were deposited on Si substrates by radio frequency (RF) magnetron sputtering and formed into the cantilevers by dry etching. To evaluate the frequency responses, we measured the vibration amplitude of the PZT bimorphs oscillated by applying the negative AC voltage. The piezoelectric microphone was demonstrated by detecting the output signal owing to the direct piezoelectric effect when the sound pressure was applied. We confirmed that the output signal of the piezoelectric microphone was proportionally increased by increasing the applied sound pressure.

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This paper reports on a pressure sensor using ionic liquid to measure the pressure of the reflux flowing in the Body-on-a-Chip that mimics human physiological response by a microfluidic device. To design the sensor structure, the sensor output signal dependence of the pressure was estimated. First, deformation of PDMS thin film depending on the applied pressure was analyzed by finite element analysis considering the non-linear material property of a PDMS, and then the resistance change was estimated as the sensor output. Next, the sensor was fabricated by multilayer soft lithography technology, and the resistance change was measured. Comparison between the simulation results and measurements exhibits almost the same trend, revealing the capability to measure a small pressure range of 0 to 12 kPa required for the Body-on-a-Chip device.

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Mechanically tunable plasmonic devices are effective for functional photonic components including highly sensitive detectors, ultra-low power optical tweezers and so on. However, there is strong limitation of excitation wavelength because of difficulties in precise alignment with single nanometer scale. We have proposed a novel mechanism based on inclination of plasmonic plates, which allows for short wavelength excitation, for effective tuning of plasmonic properties. In this study, improvements of plasmon excitation efficiencies were achieved by using a UV imprint technique. Cracks and wrinkles of Al surfaces on metallic plates were markedly suppressed compared to that on conventional PDMS plates. The devices exhibited four times higher efficiency for 405 nm wavelength plasmon excitation. Scattering losses were simultaneously decreased.

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Bacteria in various environments have very important roles as biological resources of human beings. However, more than 99% of the microorganisms that inhabit the Earth are difficult or impossible to culture and study experimentally using conventional biochemical techniques. In order to analyze the genes of bacteria that can’t be cultured, it is necessary to trap only one bacterium, break the cell membrane, and take out their DNA. Therefore, as the technique of trapping and breaking bacteria, We attempted the electrodynamic operation. By applying alternating voltages, dielectrophoretic force works and We trap bacterium. By applying pulsed voltage, we generate electroporation and breaking bacteria. We found the proper voltage for trapping E.Coli and demonstrated breaking.

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