三田 信

LIDAR(LIght Detection And Ranging) that measures distance by the laser pulse is a necessary sensor of navigation for a deep space explorer that doses a planetary exploration. Two dimension of LIDAR scanning is required from both sides of the navigation control and the science observation in order to make a 3D map of surface efficiently. This paper proposes a novel method on the beam scanning mechanism for a receiver telescope with big aperture by using MEMS technology. In addition, it reports on the result of executing the basic function experiment of the beam scanning mechanism. The scanning optics system is composed of a telecentric telescope, and a micro shutter array. This optical system has achieved a narrow viewing angle corresponding to aperture of the shutter by limiting the view of the telescope that has a wide viewing angle with the shutter. We experimented by using the shutter array of 6mm×6mm size. As a result, it succeeded that the scanning angle in the achievement of azimuth angle 8.8deg, elevation angle 8.1deg, and the field of view angle of azimuth angle 1.8deg and elevation angle 0.6deg.

We have successfully developed a novel micromechanism of random number generator (RNG) by using the silicon micromachining technique. The MEM(Micro Electro Mechanical)RNG produce a series of random numbers by using the pull-in instability of electrostatic actuation operated with a typical dc 150 volt. The MEM RNG is made by the deep reactive ion etching of a silicon-on-insulator(SOI) wafer, and is very small compared with the conventional RNG hardware based on the randomness of thermal noise or isotope radiation. Quality of randomness has been experimentally confirmed by the self-correlation study of the generated series of numbers. The MEM RNG proposed here would be a true random number generation, which is needed for the highly secured encryption system of today’s information technology.

We have newly developed a prototype model of silicon microfabricated piggyback actuator for positioning a read/write head of magnetic hard-disk drive, which is usually referred to as a dual servo system because the piggyback actuator for fine control is used in collaboration with the voice-coil motor for coarse control. The actuator is made of a 50-micron-thick SOI (silicon on insulator) wafer processed by deep RIE (reactive ion etching) of high-aspect ratio. Actuation mechanism is based upon electrostatic force generated by multiple parallel plates. Maximum displacement of 0.2μ with a dc driving voltage of 20V has been achieved with a 1mm × 0.3mm actuator of its resonance at 25kHz. An analytical model for predicting electromechanical performance has also been developed.

The micro-miniature JT cooler is a promising cooling device as an element of the micro-thermal system for semiconductor devices, which dissipate an incredible amount of heat. In particular, the thermal management of laser diodes is a serious problem because they require a large amount of power but must maintain a fixed temperature. Considering such a situation, the performance of a micro-miniature JT cooler was calculated under the assumption of a countercurrent heat exchanger operating with a laminar gas flow, and the guidelines of a micro-miniature JT cooler for optimizing pump power and size were designed from the viewpoint of minimizing the cost. The authors present the results in this paper. A micro-miniature JT cooler was fabricated from Si wafer using a photolithographic process, which is available for operation with C₂H₆ from 3 MPa to 0.1 MPa. It is shown that a cooling power of 2.1 W was obtained at 239 K with a mass flow of 51.7 mg/s.

This paper deals with the new method that makes micro-holes with electrodeposition photoresist (EDPR) as a sacrificial layer. The EDPR was deposited on a silicon-mold made by ICP-RIE. Ni film was plated on a silicon-mold covered with EDPR. Etched through a gap between a silicon-mold and the Ni film, the Ni film came off from the silicon-mold. As a result, we could make Ni films that have micro hole of 9.2µm in diameter, and 56µm in depth on an experimental basis, and verified the silicon-mold that lateral faces of columns did not bare scratch marks. Moreover, the circularity roundness was able to fill 1.5µm which was the specification of the printer nozzle.

This paper deals with the new method that makes micro-holes with electrodeposition photoresist (EDPR) as a sacrificial layer. The EDPR was deposited on a silicon-mold made by ICP-RIE. Ni film was plated on a silicon-mold covered with EDPR. Etched through a gap between a silicon-mold and the Ni film, the Ni film came off from the silicon-mold. As a result, we could make Ni films that have micro hole of 20.9μm in diameter, and 56μm in depth on an experimental basis, and verified the silicon-mold that lateral faces of columns did not bare scratch marks.