This paper focuses on a development of a cortical signal recording system to analyze an information processing system in a brain, and describes a fabricated microprobe using techniques of the microfabrication for realizing a multi-site recording. In order to identify the brain system, the multi-site and simultaneous recording is required. However, the property of the invasiveness leads to miniaturizing such a device. Therefore, the multi-site microprobe was fabricated by applying a multilayer structure of electrical circuits. Moreover, the anisotropic etching was applied in order to simplify the fabrication process. And the electrical property of this microprobe was described.
A method based on Self-Organizing feature Map (SOM) for classifying behavior patterns of autonomous actors has been proposed. This paper shows that the method has been able to display a classified behavior of gold fish after a shock was applied. The pattern of behavior is calculated using five-dimensional input vectors formed from animated pictures. This classification method is improved so that the displaying map may not be influenced by initial conditions. In this case, the Euclidean distance on competitive layer is arranged by the fuzzy inference. The Fuzzy-SOM is useful to analyze acts of the athlete in sports and refugees in an accident, because this method can deal with animated pictures. An application to a soccer game is also presented.
This paper presents a new error separation method for roundness and spindle error measurement, which is called the angular three-probe method. Three two-dimensional angle probes are employed in this method. The two-dimensional surface local slopes of the cylindrical workpiece, the radial error motion and angular error motion of the spindle, which are included in the output of each probe, can be separated from each other using the two-dimensional outputs of probes. Comparing with the conventional displacement three-probe method, the angular three-probe method is more suitable for detecting the multi-degree-of-freedom components of spindle error and roundness. In this paper, the measurement of roundness is discussed in detail theoretically and experimentally. An in situ self-calibration method, which does not require extra angle references, is proposed to calibrate the angle probes. Experimental results have indicated that the roundness can be measured with a repeatability of approximately 0.04μm. Comparison of roundness measurement with the displacement three-probe method has also been conducted.
A system measuring for nanoparticles on a silicon (Si) wafer using a light-scattering method was developed previously. The present research aims at developing a new method for measuring a scratch width of the nanometer (run) order on a Si wafer using the developed system. In this method, the measurement of the width of a scratch was attempted by detecting the amount of scattered light obtained from the scratch and calculating the spherical volume of a particle which would approximately replace the unit volume of the scratch having a concave shape. The measurement of a nanoscratch on a Si wafer surface, where the scratch was created using an atomic force microscope (AFM) needle, was carried out using the present measuring system and an AFM. As a result, the use of this measuring system has enabled the measurement of the scratch width with a high accuracy. The measurement of scratch width on the surface of a bare Si wafer has been attempted using this measuring system. Consequently, it has been verified that this measuring system is applicable for the detection of scratch widths of nm order on a Si wafer.
The authors have proposed a new optical method for measuring surface roughness by use of a halogen lightsource and a CCD camera. Based on the Torrance-Sparrow model, the proposed procedure theoretically converts the data of the reflected light into surface roughness represented in Rq (roughness in root mean square). In this paper, we attempt to use the proposed optical roughness sensor as a proximity sensor, which can measure both the gap distance between the sensor and the surface and the inclination angle of the surface. By moving the optical sensor actively, the proposed optical roughness sensor can be used as a proximity sensor.
A high-density mounting technology for liquid crystal drive IC and liquid crystal substrates has been developed to achieve high-definition liquid crystal displays. The material to connect liquid crystal drive IC and the liquid crystal substrate is anisotropic conductive film (ACF).Formerly, 250μm connection pitch was used as a joining material between liquid crystal drive IC and liquid crystal substrate. Now, connection pitch has been increased to 50μm. To achieve this high-density mounting technology, it was necessary to clarify the stretching mechanisms for the liquid crystal drive IC and anisotropic conductive film, which have different thermal expansion rates. Apart from the elucidation of the stretching mechanism, by the discovery of new mounting conditions to restrain the stretching, mounting technology featuring a 50μm connection pitch for joining, which had been thought impossible in the past, has been established. Thus realization of the high-definition liquid crystal display has been achieved.
In grinding, it is required to clarify the processing phenomenon and the process to be made intelligent. The acquisition of detailed tool information is necessary for the purposes. Consequently, not a small number of measurements for wheel working face has been reported. This measurement is expected to be high-speed and performed on the machine. However, there is no measuring system, which is suitable for these purposes. Therefore, this paper describes a high-speed 3-D measuring system for wheel working face on the machine. In this system, a sensing head similar to a laser displacement meter is used. The sensing head is attached to grinding head by two automatic stages. The wheel rotating at 30m/s peripheral speed is scanned by these stages. The scanning resolution is 3μm for X, Y, and Z respectively. This system essentially does not have any limitation for the measurement area. The results of measurements are studied experimentally. As a result, the data obtained by this system is in good agreement with that by a laser microscope.
In ultraprecision cutting by which surface finish is nano-meter order, the problems which are not necessary to consider in ordinary cutting occur. One of these is the step at grain boundary on machined surface which is generated by the difference of elastic recovery of crystal grains after cutting edge passing because of mechanical characteristics of crystal grain affected by crystal direction. In this study, in order to make clear the mechanism of the surface finish generation in ultraprecision cutting of Al-Mg alloy, the relationship between clearance angle of tool and surface finish is analyzed quantitatively taking notice of step at grain boundary. As a result, it is confirmed that burnishing effect with clearance of cutting tool, which strengthen with a decrease of clearance angle, improves surface finish in ultraprecision cutting of Al-Mg alloy.
This paper presents a method of real-time adaptive control of tapping for the difficult-to-machine material such as superheat resistant alloy (Incone1718), titanium alloy (Ti-6AI-4V) and stainless steel (SUS 304). Normally adaptive control has disadvantage to be applied in tapping process because C-axis requires high acceleration in the process. In general, conservative cutting speed is applied to such difficult-to-machine materials, since high cutting speed intensify tool wear. Moreover, only in the case with low cutting speed, C-axis is able to be operated with high acceleration to stop its rotation. Therefore, real-time adaptive control such as adaptive pecking is effective for these materials. By introducing adaptive control, chip jamming is avoided during tapping process. In addition, it is possible to predict the tool life by counting number of pecking in successive tapping process.
This paper deals with the micro-welding of the glass substrates by YAG laser beam. The micro-welding technology is required for the precision assembly of the micro components in the optical transmission devices, LCD plate and so on. In the conventional welding method of the glass materials, glass components were bonded to glass substrates by bond material which was melted by heat energy. In our proposed method, a pair of glass plates was overlapped, in which the absorbent was painted on the welding area of glass surface, and the YAG laser beam was absorbed in only the painted area. Therefore only the interface between two plates will be welded and glass surface will be clear. In this study a feasibility study of a newly developed welding method was carried out. In the experiments, slide glasses were welded by YAG laser beam, the welding point was observed and welding strength was measured.
This paper introduces a new machining device that enables us machining tests of hand-brittle materials under high hydrostatic pressure, up to 400MPa. The new machining device consists of a pressure vessel in which a turntable and a tool stage mechanisms are installed. The device equips several sensors in the chamber. A load cell for cutting force measurement and position sensors of the tool stage were specially designed for use under high hydrostatic pressure. A pressure gage and a thermometer are placed near the cutting tool so that environment of the machining region can be monitored Sensitivity and accuracy of these sensors were tested, and it was shown that the sensors are available for machining test wider high hydrostatic pressure. A plate glass was use as a specimen for machining test wader high hydrostatic pressure. Machining defect and tangential cutting force were measured. Results show that hydrostatic pressure reduces machining defect, but increases cutting force.
In order to develop a new ultra-precision and ultra-clean machining method, we studied electrochemical machining in ultrapure water. In this paper, we newly performed electrochemical machining in ultrapure water under the cathode specimen condition to understand the interaction with H atom. We found that Al and Si specimen whose surfaces are oxidized under the anode condition are etched off under the cathode condition. It was also confirmed that pH value near the cathode is basic (pH=9) in the experiment. These results indicated that OH molecule is generated at cathode surface, which is concerned in the etching mechanism of cathode surface with H atom. As the result of these experiment, we proposed that etching mechanism of cathode specimen condition is as follows, (1) Adsorption of H atoms on the cathode surface, (2) Generation of OH molecules at cathode surface, (3) Chemisorption of OH molecules to the H-adsorbed cathode surface and etching off the surface atom.