Structures of interfaces between materials and lubricants are analyzed by neutron reflectometry and discussed in the series of studies. In this paper, three kinds of DLC films having different surface energies (normal DLC, hydrophilic DLC and hydrophobic DLC) were prepared as base materials, and water and 2-propanol were selected as lubricants. The instrument we used was a neutron reflectometer 'MINE' in Japan Atomic Energy Agency (JAEA). The DLC films were soaked into the lubricants in a specially-designed sample holder, and the neutron reflectivity profiles from the interface between DLC films and lubricants were directly obtained. Through an analytical fitting approach with Parratt's theory to the obtained profiles, authors presented the strict structure of the interface.

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Since the discovery of carbon nanotubes(CNTs), the remarkable structural, electrical and mechanical properties as carbon material has attracted many researchers, and the synthesis of high quality CNTs using various methods have studied. Kusunoki et al. have reported that CNTs with high-density and well-alignment are formed vertically on a silicon carbide substrate. CNTs on SiC substrate could be used for tribomaterial as high friction or wear proof materials because each CNT covalently bonds with the SiC substrate. Thus, we have studied about interface strength of CNT film by means of the combination of AFM nanoscratch test and finite element analysis. From the result, we could assume that shear strength at the interface of CNT films was about 180 MPa. And it was no dependency on the length of CNT.

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This paper describes wall-climbing robot based on adhesion mechanism of ants. Adhesive pads which are similar to adhesive organs of ants were fabricated using micro fabrication techniques. In order to adhere the pad to a vertical wall, a small amount of liquid was supplied to the surface of the adhesive pad through micro channels using a micro pump. Tangential adhesive forces between the adhesive pad and a glass surface were measured. Furthermore, a hexapod robot that walks in the same gait as that of an actual ant was fabricated and the adhesive pads were integrated in each foot of the robot. The robot successfully adhered on a vertical glass surface.

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This paper describes a novel micromotor using surface tension of liquid droplets. As the dimension of mechanical elements decreases, surface tension becomes dominant compared to gravity force, and it often causes adhesion problems between two surfaces. On the other hand, recent studies show that surface tension can be utilized for transportation of liquid droplets and lubrication of hydrophobic surfaces. In this study, a micromotor that is driven and lubricated by surface tension of water droplets has been developed. The motor consists of stator electrodes, water droplets and a rotor. The water droplets are transported on the stator by using electrowetting on dielectric (EWOD) and a rotor is supported and rotated by the droplets. A rotor of 5-mm diameter was successfully rotated at 320 rpm.

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This paper discusses biomimetic water strider robots that have microfabricated hydrophobic legs. Various kinds of supporting legs with hydrophobic microstructures on their surfaces were developed using MEMS (micro electromechanical systems) techniques. The lift and pull-off forces of these supporting legs were analyzed theoretically and then measured. The experimental results were in good agreement with the calculations. Water strider robot with twelve microfabricated legs driven by a vibration motor successfully moved on a water surface and also made left/right turns by exploiting differences in the resonant frequencies of the legs.

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Coarse-grained molecular dynamics simulations were performed to analyze the surface morphology of lubricant films composed of PFPE (Perfluoropolyether) Zdol and Trifunctional PFPE. Trifunctional PFPE has the functional group at the middle of a lubricant molecule as well as functional endgroups at the head and tail of the lubricant molecule. The mesh scanning method was introduced to detect the film surface. The effects of the functionality and length of the lubricant molecules on a flat solid surface with periodic boundary conditions were studied. We clarified that the film surface of the Trifunctional PFPE was smoother than PFPE Zdol2000 when compared at the condition of the same film thickness.

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