| 1. Superplasticity in Nickel-base Superalloys
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| Superplasticity is a phenomenon which allows materials with high strength and low ductility, such as nickel-base superalloys, to be worked easily. Research towards the creation of new superplastic alloys, involving investigation of both microscopic structural properties and metallurgy, has lead to non-destructive testing methods which use internal friction techniques. Investigations into macroscopic phenomena and applications of superplastic alloys have lead to the development of a new forging method.
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| 2. Oil Film Thickness Tester for Pressurized Refrigerant Atmospheres
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| To prevent ozone layer depletion, conventional refrigerants are replaced with alternative refrigerants, causing various tribological problems. For long system life and reliable operation, compressors must be operated under fluid lubrication conditions, and the physical properties of refrigerant-oil mixtures are important. The oil film thickness tester achieved the first reliable measurement of the refrigerant-oil mixture film thickness needed to cope with the tribological problems encountered with the new refrigerants.
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| 3. Artificial Muscle
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| Muscle-like actuators are actively being sought by researchers in the fields of robotics and medical devices. In the study of polymer actuators a novel polymer gel-material has been developed which can generate contraction force and mechanical power density as high as frog muscle. In the photograph an artificial muscle model lifts up a ball by exchanging solvents from water to acetone.
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| 4. Prosthetic Devices Developed Through the Study of Human Bones and Joints
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| In this project, the relationships between the different components of human joints were studied. Analysis of the strength and stiffness differences between loaded and unloaded regions indicated that bone and annular cartilage respond to load by remodelling. A continuum model of human joints was developed, and applied to the development of artificial joints using advanced biocomposite materials such as alumina, zirconia, ceramic coated Ti alloys, and ceramic filled polyethylene.
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| 5. Optical Correlator Using a Liquid Crystal Spatial Light Modulator
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| Optical correlation systems have the potential to perform extremely high-speed pattern recognition, a characteristic anticipated to be of great importance in the next generation of intelligent manufacturing machines. However, conventional optical correlators have been rather difficult to actually use in a routine production environment. In order to overcome this problem, a new phase-only spatial light modulator has been developed, which has made the construction of flexible optical correlation systems possible.
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| 6. High-efficiency Propulsion Systems for Solar Powered Airships
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| Unmanned solar powered airships have great potential for application such as environmental monitoring and communications relay in the least windy lower stratosphere. They have advantages for monitoring typhoons and the Antarctic Ozone hole. However, high-efficiency propulsion systems are needed. Active boundary layer control techniques, in which boundary flow over the airship skin is intercepted by a slot towards the back of the vehicle and ejected as a jet, were developed for improving overall propulsion efficiency.
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| 7. New Acoustic Microscope
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| In order to perform sub-micron analysis of material properties, surface defects and thin films, a new acoustic microscope has been developed. This microscope uses a sharp tip with a radius of a few tens of nanometers to detect the ultrasonic vibration of the sample surface, and has already been commercialized by an instrument manufacturer to perform non-destructive observation of crystal lattice defects and evaluation of lubricant molecules on magnetic recording media.
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| 8. Micro-gripper
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| A micro-gripper has been developed which can be utilized for assembling micromachines and miniature machines. The gripper consists of a force intensifying mechanism using multiple spring joints and links, and a piezo actuator. This mechanism is a one-tip type produced by etching a Be-Cu thin plate. The gripper is 23 mm long, weighs 4 g, and can hold parts weighing up to 1 g.
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| 9. In-cylinder Observation of Diesel Combustion by High Speed Shadougraphy
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| In this project, a system was developed which allows the simultaneous photographing of shadowgraphs and direct images of diesel engine combustion flames. Although the principle of this technique is very simple and it is easy to put into practice, it has proven extremely useful in gaining a complete picture of the fuel spray, combustion flame, and soot behavior in diesel engine cylinders.
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| 10. Hydrogen-powered Vehicle
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| In this project, a practical hydrogen-powered vehicle was developed, which used several new technologies. Amongst these were the use of a new type of metal hydride for fuel storage, a spark ignition engine which featured direct injection of low pressure hydrogen gas, and electronic control of the total engine system. Tests showed the feasibility of practical, high performance hydrogen-powered vehicles.
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| 11. Stirling Engine
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| From 1982 to 1987, MEL was involved in the Moonlight Project, and as part of this work, carried out fundamental studies towards improving the design of Stirling engines. The work covered investigations of design methods, heat exchangers, and gas seals, and culminated in the production and performance testing of four practical engines and their associated systems.
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| 12. Event-driven Knowledge-based Control Machining System
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| An intelligent machining system was developed which has knowledge of machining processes similar to that of a trained machinist, and is able to deal with unexpected accidents. When an abnormal or faulty condition was detected, the system could reason a strategy to avoid potential trouble and make a corrected control command using its knowledge-base. Intelligent sensing technologies such as in-process tool failure diagnosis based on Wavelet Transform have also been developed.
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| 13. Flexible Manufacturing System Complex with Laser Processing
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| From 1977 to 1984 work was carried out towards the development of automated systems for the small batch production of machine components. MEL played a leading role in the planning and execution of this project, and in the final stages a test plant was constructed in Tsukuba for operational evaluation. The plant included a 20 kw laser, made use of new flexible machining techniques, and was the subject of world-wide attention.
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| 14. Two-Fingered Hand for Micro-Manipulation
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| To achieve dexterous precise manipulation, a two fingered microhand has heen developed from ideas based on chopstick usage. The hand has two layers of parallel mechanisms, each with six degrees of freedom. The lower layer provides global motion of the two fingers, and the upper layer allows relative motion of one finger with respect to the other, for example, the motion to open and close the fingers. Using this mechanism, coordinated motion of the two fingers to manipulate micro objects can be achieved simply without complicated control algorithms. The hand could successfully manipulate a glass hall 2μm in diameter to an accuracy of 0.1 μm.
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| 15. Biped Walking Robot "MeltranⅡ"
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| Anew control method for biped walking robots based on "linear inverted pendulum mode" has been developed. It can immediately generate each leg joint trajectory which enables stable dynamic walking under the given body trajectory. The method has been implemented on the biped walking robot "Meltran Ⅱ" which was originally developed at MEL and confirmed to be effective. Using this method, the robot could not only walk forward, backward, and step in place, but also move on an irregular surface with sensory feedback.
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