The well-controlled, complex three-dimensional fiber structures would be more useful as optical devices and sensors. Optical fiber micro-machining was attempted by combination of plasma etching and photolithography technology. In addition, a Ni plating technology and Ni stencil mask were introduced newly into fiber micro-machining. As the results, optical fibers with periodically stepped diameter or with micro-holes were realized and discussed as wavelength filter or transmitted light monitor.

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This paper presents the development of electrophysiological biosensor. The developed sensor allows a batch-measurement by detecting all signals from a large number of cells together. The developed sensor employs the same measurement principle as the patch-clamp technique. A single cell is sucked and clamped in a micro hole with detecting electrode. Detecting electrodes in arrayed micro holes are connected together for the batch-measurement of signals a large number of cell signals. Furthermore, an array of sensors for batch-measurement is designed to improve measurement-throughput to satisfy requirements for the drug screening application.

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The final purpose of this study is to establish a method to realize three dimensional (3-D) microstructures with free arbitrary shaped sidewalls in “Moving Mask Deep X-ray Lithography (M²DXL)". In this paper, a new algorithm named “Inverse approach" applying Fourier transformation technique was proposed to theoretically determine a suitable mask movement pattern for a target shape. As a first step toward completion of this approach, the algorithm in 2-D space, i.e. vertical and lateral, has been developed. In order to confirm the validity of 2-D Inverse approach, a V-shaped groove with a cross -sectional shape of 40 μm opening and 20 μm depth was adopted as a target microstructure. The straightforward application of the 2-D Inverse approach to the V-shaped groove fabrication did not yield a satisfying result. However, one simple correction of a distributed dose profile firstly expected to realize the target microstructure in this algorithm allowed the successful fabrication of the target V-shaped groove microstructure. Furthermore, we showed that the Inverse approach provides derivations of not only the suitable mask movement pattern but also the optimal mask and movement patterns which contribute to reduce the time and cost for prototyping.

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In this research, we built an experimental setup for measuring the water content in plants and food, and for determining the water/ice state of a sample. The setup consists of a 35 GHz Gunn oscillator producing about 10 mW of output power, two horn antennas and a power meter. We have checked that the absorption of a leaf is directly proportional to its water content, and we could show how changes of the water content depend on photosynthesis, by intermittent illumination with a white fluorescent lamp. In another direction of research, we verified that the difference in the absorption coefficients for water and ice is significant, and we could discriminate and monitor the frozen state of water and food material. All these experiments demonstrate the possibility of applying millimeter waves to fields such as botany, agriculture, and food industry.

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The activity of an enzyme, captured in a micro chamber array, at elevated temperature has been successfully measured thanks to the rapid temperature control enabled by an on-chip micro heater. The enzyme, β-Galactosidase, survived short exposure (4 seconds) to high temperature at which it was severely damaged by longer exposure. Its activity at the higher temperature (around 60°C) was shown to be 4.2 times greater than that at 23°C. Furthermore, the degree of accelerated activity is expected to be controlled by changing the frequency of the heat pulses.

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Wrong:Shinsuke Katshhara
Right:Shinsuke Katsuhara

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