This paper reports multiple channels of surface acoustic wave (SAW) sensors. We realized by providing reflectors with different positions in the SAW propagation delay line for eight channels of the passive wireless SAW temperature sensors specified low-power radio station.

A fabrication method of silicon probe has been developed for wafer-level-testing of semiconductor with narrow-pitch electrodes. The silicon probe consists of probe-tips, beams and three-dimensional wirings. The probe-tips and beams are fabricated by anisotropic etching with KOH aqueous solution. The beams were conventionally fabricated with etching a back side of substrate after etching a top side. However, after the back side etching step, the defects were observed on the back side of beams. We clarified that the defects were caused by etching that proceeds from defects in the silicon oxide layer on V-grooves with a scanning electron microscopy (SEM). Thus, we propose an improving fabrication method, which the beams are formed by etching from the both sides of silicon substrate. With this method, narrow-pitch beams on a silicon probe can be fabricated without defects.

In this study, we developed a dry-nano-polishing technique using reactive ion etching for ultra thin titanium wafer. The surface of titanium coated with photoresist is polished by reactive ion etching using SF₆/C₄F₈ gas. Etching speed of titanium and photoresist were adjusted to close to each other by changing temperature and ratio of SF₆/C₄F₈ gas. By etching titanium under these conditions, the smooth surface shape of the resist was transferred to titanium. By combining with photolithography, it is possible to polish a specific part.

Cell separation technique is essential for the detection of circulating tumor cells in blood and for enrichment of stem cell in regenerative medicine. However, conventional methods require cell labeling such as antibodies, which may damage the cells during the operation. Therefore, dielectrophoresis (DEP), a "label-free" separation technique that eliminates the effects on cells, has been attracting attention. In this paper, we investigated the dielectric properties of Jurkat cells derived from human T-cell leukemia cells by dielectrophoretic velocimetry (DEPVM). An equivalent circuit model of the cell was constructed and the frequency characteristics of the voltage of each layer of the cell were calculated. As a result, it was shown that the live and dead cells showed opposite dielectrophoretic forces in the region below 10 kHz, indicating the possibility of separating them. The agreement between the theoretical calculations and the experimental results shows the validity of the equivalent circuit model.

We propose a tomography method to reconstruct gas distribution based on compressed sensing in Fourier domain for a laser scanning gas sensor, e.g. methane gas. 3D reconstructed results measured by an onboard 2-axis laser scanning gas sensor on a movable robot were successfully obtained with fewer artifacts, and denote that the number of laser scanning and robot movement can be reduced with keeping the same gas distribution mapping accuracy.