An olfactory display is a device that presents an odor to the user. In this research, odor components were used to reproduce a variety of scents by blending them at the specified ratio. A perfume is supplied from an electroosmotic pump to a microdispenser, and the multiple odor components ejected from the microdispensers are atomized by the surface acoustic wave device to produce the blended odor. Digital-to-Analog converter was introduced to promote automation and jigs were improved for convenience. A total of 21 solenoid valve droplet volumes were investigated, and it was found that the performance of the solenoid valves and the discharge volume differed for each solenoid valve. We then verified through sensory test whether calibration of the droplet volume is necessary, and found that it is better to compensate for the droplet volume for smell presentation.

In this study, we investigated dependence of carrier density and film thickness on H₂ gas sensitivity using tin dioxide (SnO₂) films deposited by RF magnetron sputtering. Our aim is fabricating a gas sensor that can detect ppb-level gas concentrations for health care applications. It had been reported that lower carrier density and thinner film thickness contributed improving sensitivity of a gas sensor. We balanced lower carrier density and thinner film thickness by using a sapphire substrate for depositing tin oxide in addition to annealing treatment to tin oxide films. In the result, we clarified that thinning film thickness of tin dioxide affected on improving its gas sensitivity more significantly than lowering carrier density.

In this study, iron oxide thin films are prepared under various heat treatment conditions, and their crystal structures and moisture-sensitive characteristics were evaluated to clarify the usefulness of iron oxide thin films as humidity-sensitive materials for humidity sensors. In addition, the possibility of a humidity sensor with a wide dynamic range was investigated by evaluating the relationship between the film thickness of the iron oxide thin film, the electrode width of the device, and the humidity-sensitive characteristics. As a result, it was found that the crystal structure of α-Fe₂O₃ exhibits relatively good humidity sensitivity compared to other crystal structures, and that the sensitivity to humidity can be adjusted by appropriately selecting the electrode width and film thickness of the device. Therefore, the α-Fe₂O₃ thin film may be useful as a moisture-sensitive material for wide dynamic range humidity sensors by appropriately adjusting the film thickness and electrode width.

The aim of this research project is to attain accurate gas-source localization in outdoor environments with large wind fluctuations. For this purpose, we propose to use a long short-term memory deep-learning framework to time-series data collected by a sensor network consisting of multiple gas sensors and an anemometer. This paper describes impacts of the length of time-series data and smoothing of wind data provided to a deep neural network model. We have collected three datasets by placing 30 semiconductor gas sensors and one ultrasonic anemometer in an outdoor field in different seasons. We have found that the success rate of gas-source location estimation can be effectively increased by removing high frequency fluctuations in the time-series data of the wind velocity vector by taking moving average before applying the data to the neural network. By adjusting the data length provided to the neural network and smoothing the wind data, the success rate of gas-source location estimation has been increased from 82.5% to 86.7%. A success rate of 78.8% has been obtained even when half of the gas sensors have been removed.

In this study, we proposed a cuff-less blood pressure measurement using a medical tape sensor with an embedded hetero-core optical fiber. The tape sensor pasted on the skin can directly detect pulse wave signals with a simple measuring device. Pulse transit time (PTT) was obtained from the time difference between the two pulse waveforms at the neck and foot. Systolic blood pressure (SBP) was estimated from PTT and the regression equation. The result shows that the maximum prediction error was 3.8 mmHg in five healthy young subjects. The SBP data were evaluated using a Bland-Altman method to assess the agreement of SBP data estimated by the proposed method with those measured by the cuff-based electronic sphygmomanometer. The mean ±1.96 standard deviation of the estimated SBP against the reference was -1.3±5.1 mmHg. The results show that the proposed non-invasive blood pressure measurement method can measure blood pressure, and its accuracy is comparable to that of the cuff-based electronic sphygmomanometer.

Recently, three-dimensional cell culture methods are focused on the fields of drug discovery and regenerative medicine. In the three-dimensional cell culture methods, cells are incubated to stereoscopic cellular structure (cellular spheroids) and metabolic organs, which are absorption tubes and excretory organs, are formed between cells. The metabolic organs are functional for drug metabolism in the tissue engineering. Conventional three-dimensional cell culture methods are used by nanoimprinted vessel, which are fabricated by a mold tool with Micro Electro Mechanical Systems (MEMS) processes, i. e. deposition, photolithography, and etching. Accordingly, the nanoimprinted vessels have very simple shapes, which are rectangular prism and cylinder. However, cells are not summarized in the center of the vessels, and the cellular spheroids are not efficiently incubated.This paper represents the fabricating method of dome-shaped vessels for efficient cell culture systems. In the three-dimensional cell culture, the dome-shaped vessels make it easy to collect the cells in the center of the vessels. However, the fabricating dome-shaped vessels are difficult to fabricate with only MEMS processes. To overcome this problem, the semiconductor post-process is applied to the fabricating process of dome-shaped vessels. The solder bump, which is connected between the semiconductor device and the external board, are easily formed to dome-shaped structure by reflow method. The dome-shaped mold tool, which solder bumps are plated on the substrate, is replicated to the resin.