Papers by Keyword: Structured Surface

Abstract: Rolling Imprint Lithography is an Enabling Technique for the Mass Production of Ultra-Precision Micro-Structured Surfaces which are Widely Used in High Value Added Optical Products such as Backlight Guides for Display Devices. the Accuracy of the Produced Micro-Structured Surfaces Relies Heavily on the Master Roller of which Quality is Difficult to be Controlled by Traditional Off-Line Measurement Process due to the Large Dimension and Heavy Weight of the Workpiece. this Paper Presents a CCD Based Non-Contact Measurement System to Perform the on-Machine Measurement of the Structure Pattern on Machined Rollers. Instead of Measuring each Single Structure on the Roller, the System is more Focused on the Characterization of the Conformance of the Structure Pattern with the Designer’s Requirement. Low Angle Monochromatic Light is Used to Extract the Structure Pattern on the Machined Roller Using a High Magnification Objective Lens with a High Resolution CCD Sensor. the Image Processing Techniques are then Employed to Characterize the Captured Image Based on the Designed Pattern Structure. the Developed System has been Mounted on a Single-Point Diamond Turning Machine to Measure the Machined Structured Roller, and the Results Indicate that the Developed Measurement System is Able to Perform the on-Machine Measurement and Characterization of the Structure Pattern of the Machined Roller with Sub-Micrometre Accuracy.

Abstract: A wavelength scanning interferometry system for fast areal surface measurement of micro and nano-scale surfaces which is immune to environmental noise is introduced in this paper. It can be used for surface measurement of discontinuous surface profiles by producing phase shifts without any mechanical scanning process. White light spectral scanning interferometry, together with an acousto-optic tuneable filtering technique, is used to measure both smooth surfaces and those with large step heights. An active servo control system is used to serve as a phase compensating mechanism to eliminate the effects of environmental noise. The system can be used for on-line or in-process measurement on a shop floor.

Abstract: Spray cooling is considered to be one of the most promising electronic cooling methods, since it has several unique advantages such as high heat dissipation, small fluid inventory, and uniformity of heat removal. However the spray cooling performance could be further improved, which can be expressed by the combination of a better heat removal capability, a higher cooling efficiency, and the more uniform surface temperature distribution. In this paper, recent research developments on spray cooling characteristics under different working conditions are reviewed, possible approaches to improve the spray cooing performance are also proposed. Especially spray cooling systems with both enhanced surface and lower system pressure would be be full of attraction.

Abstract: This paper discusses a design of micro-structure on the surface in contact with human from the standpoint of frictional property and feeling. Coefficient of friction on a floor varies with sliding speed in wet environment. At some condition where hydrodynamic pressure becomes dominant, the coefficient decreases and causes slip. Experiments were carried out on a special setup and structural design to decrease this pressure was discussed. It was found that structures of sub-millimeter pitch are effective in floor design. Then, the surface structure for handles was discussed. In this case, feeling becomes important rather than the change in sliding speed condition. It was found that sub-millimeter sized structure can improve the feeling while keeping high coefficient of friction under wet condition.