This study develops a real-time system for visualizing electrostatic field distribution measurements. The system is based on a field programmable gate array (FPGA) and uses a microelectromechanical systems (MEMS) micromirror array. Subsequently, the electrostatic field distribution was visualized through the FPGA-based soft-core processor. The maximum and minimum full-scale errors of the developed system were 4.5% FS and 0.2% FS, respectively. In measuring a single point charge with 5% FS, the developed system performed equivalently to that of an electrostatic sensor.

A batteryless bicycle speed recorder with a hub dynamo and FM/AM radio has been developed. The hub dynamo functions as both a power source and a speed sensor. It produces a voltage waveform with fourteen AC cycles per rotation of the bicycle wheel, which enables precise determination of speed and acceleration. A sound data of radio broadcasting was also used as time stamp function. The data is stored in a magnetoresistive random-access memory (MRAM). A road test showed that a fabricated speed recorder mounted on a bicycle stored and reproduced accurate values of a large acceleration and its duration when the brakes were suddenly applied while the bicycle was being ridden.

The microreactor has attracted attentions because the microrecter can realise a new phenomenon and a new reaction in the field of micro-chemical process. In this study, a temperature controlled microreactor system using a microchannel of stainless steel and a Peltier device has been developed. In this system, the temperature device made of the microchannel device has been controlled from 8.7℃ to 65.8℃. The hot fluid has been quenched successfully. To evaluate the performance of this system, a recrystallization of alum has been used. In this temperature controlled microreactor system, the average particle diameter and standard deviation were 9.2 and 10.1µm when air flow rate and solution flow rate were 452 and 2.4ml/min. These results show that the proposed system has realized the miniaturization and uniformization of the alum crystals. As a result, the effectiveness of this system has been indicated.

Electrical impedance imaging is an emerging medical imaging technique which can produce tomographic images of impedance properties. Many fusion systems in which impedance imaging combined other modalities are developed, but no technique currently exists the multi imaging system that could simultaneous imaging of the same region. To realize the multi-imaging systems, an improved fusion impedance imaging technic with electrical and ultrasonic multi-imaging system is developed. Especially, this paper investigates the accuracy effects against the increasing sensor number and proposes an improved parameter adjustment method. The numerical simulation and the practical experiment are conducted on the assumption the breast cancer. The imaging result shows the accuracy of estimating impedance can be improved by the increasing the sensor number and the modification of the parameter setting.

Electrical impedance of plants is related to condition of the plant's cell tissue. In existing works, the impedance has been utilized for understanding the condition of the plant. There are three kinds of electrode for measuring the impedance: a needle electrode, a metallic foil electrode, and a conductive gel electrode. However, these electrodes have problems. The needle electrode injures the plants. The metallic foil electrode does not stably contact to the plant because the plants has curve and convexo-concave surface. The conductive gel electrode including NaCl blasts the plants. We proposed a conductive unvulcanized rubber electrode for measuring the electrical impedance of the carrots. Characteristics of the conductive unvulcanized rubber electrode were soft, deformable, and self-adhesive. Thus, the electrode was noninvasive and did not damage to the carrots. In experiments, we showed that the conductive unvulcanized rubber electrode could be utilized for measuring electrical impedance of a carrot for 912 hours. Moreover, we observed that the contact area of the electrode was larger than the contact area of a conductive adhesive tape electrode.

In this paper, we report for the first time a programmable active metamaterial leaky-wave antenna using a monolithically integrated MEMS (microelectromechanical systems) switch array. The metamaterial antenna is integrated with surface micro-machined capacitive switches that could be electrostatically actuated to alter the electrical conditions in the antenna units by the external voltages supplied through the bonded-wires. Due to the discrete periodical metamaterial units that can be independently controlled, the equivalent propagation constant β of the antenna is manipulated to spatially modulate the radiation patterns, thereby enabling programmable antenna performances. Furthermore, we discuss and analyze the spatial and the transient resolution of the radiation for the first time, by which continuous spatial scan is synthesized from discrete periodical antenna patterns of digital control. Given the number of units, the scan speed is found to depend on the electromechanical resonant frequency of the MEMS modules. Experimental results on a 5-bit programmable antenna agree well with the analytical simulations.

In recent years, miniaturization and higher performance have been increasingly required for the electronic devices in the measurement system or electronics. In order to accomplish these goals, sensors and actuators using the MEMS have been widely studied. A flow sensor is one of such MEMS sensors. There are various types of flow sensors such as an electromagnetic type, a float type, an ultrasonic type, an impeller type, or a thermal type. Among them the thermal type has the potential of fulfilling the above requirements and is easy to be produced using the MEMS technology. Based on these backgrounds the micro thermal flow sensor using SOI-MEMS technology has been extensively studied. The authors conducted a research on thermal micro flow sensor using SOI-MEMS technology which can easily be integrated with other sensors such as acceleration sensors. However, there are fluctuations in sensitivity and offset due to thermal stress and aged deterioration in a bridge circuit system including ordinary temperature sensitive resistors. In this paper, we investigated an oscillator type thermal micro flow sensor aimed at suppressing these effects by utilizing the time delay of thermal conduction.

Magnetic sensor characteristics of InSb Hall element with a ferrite sandwich structure were investigated. This sensor can accurately measure a magnetic field of the order of 1 µT and the standard deviation of the measured magnetic field is about 130 nT. Fluctuation of the offset voltage and noise power spectrum was measured and 1/f noise was observed up to 10 kHz for applied current of 8 mA. It was also found that the noise power spectrum density was proportional to input current.