Materials Science Forum Vols. 505-507

Abstract: Electromagnetic optical scanning mirrors for both horizontal and vertical scanning of a Laser Projection Display have been proposed. Electromagnetic actuation is selected because of the millimeter-sized mirror. For low cost reason, the glass and PMMA films are respectively used as the main structure of horizontal and vertical scanning mirrors. A mathematical model considering the operation frequency of the Laser Projection Display has been derived to fast design the geometry of the scanning mirror. In order to machine scanning mirrors with high quality geometry, the 193 nm excimer laser is used as the major machine tool. Different control circuits have been developed to control both horizontal and vertical scanning. The scanning frequencies, 4.15 kHz and 260 Hz respectively for horizontal and vertical scanning mirrors, have been measured by laser Doppler vibrometer. Comparing to other optical scanners, 193 nm excimer laser machined optical scanning mirrors have advantages in low cost and easy to fabricate. In this paper, a Laser Projection Display consisting of the horizontal and vertical scanning mirrors has also been built to show the application potential. A 2-D single color image with resolution of 46 × 32 pixels, 4.15 kHz of horizontal scanning frequency and 60Hz of regulated vertical scanning frequency has been demonstrated.

Abstract: An on-line image measurement system for curve grinding was schemed out according to the working process. Because of interaction between detection precision and field of view, it is difficult to realize high detection precision at a large field of view. In order to settle this problem, a detection method based on circular tolerance zone was presented according to grinding process and wheel shape. Real-time images of work piece can be gathered while using synchronal control and outer trigger technology. Using curve fitting method, the work piece image edge can be located to sub-pixel values. Experiments show that the proposed method in this paper is effective, and its detection precision and results are reasonable.

Abstract: One of the most popular mathematical tools in fields of robotics, mechanisms and computer graphics is the 4x4 homogeneous transformation matrix. In previous work we applied this matrix to the optical domains of flat and spherical surfaces for: (1) skew ray tracing to determine the paths of skew rays being reflected/refracted; (2) sensitivity analysis to determine by direct mathematical analysis the differential change of incident point and reflected/refracted vector with respect to change in incident light source. The present work extends our previous work to include the case of parabaloidal boundary surfaces.

Abstract: One of the most popular mathematical tools in fields of robotics, mechanisms and computer graphics is the 4x4 homogeneous transformation matrix. In previous work we applied this matrix to the optical domains of flat and spherical surfaces for: (1) skew ray tracing to determine the paths of skew rays being reflected/refracted; (2) sensitivity analysis to determine by direct mathematical analysis the differential change of incident point and reflected/refracted vector with respect to change in incident light source. The present work extends our previous work to include the case of parabaloidal boundary surfaces.

Abstract: An intelligent E-Manufacturing system was developed in this paper. The high speed machining center was rebuilt using 3D CAD system. The moving table (X axis), span column (Y axis), spindle (Z axis) and the tool changing system were modeled precisely. The high speed cutting (HSC) experiments of AL 6061 were carried to obtain the cutting forces and surface roughness for different cutting conditions. The backward propagation supervised artificial neural network (ANN) system was developed to predict the results of the high speed cutting. The intelligent virtual reality (VR) system of high speed cutting was developed integration the ANN and the VR environment. The users were able to learn the manual and the CNC operations of the HSC machine. The actions of users were recorded and evaluated to judge the learning results. The cutting results of forces and surface roughness of user’s NC program was predicted by the ANN system to assist the NC programmer to adopt the suitable cutting parameters. The developed VR system was deployed to the internet webpage to supply a good E-Learning and E-Manufacturing environment.

Abstract: This paper describes the development of a virtual CNC controller. Controller is the major driver for a CNC machine. Similarly, virtual controller is the key driving component for a virtual CNC, which is a three-dimensional digitized physical CNC. A virtual CNC can exist in every PC serving as the complementary safer counterpart in lecturing and learning the hand on operation of expensive machinery such as five-axis milling machine, high speed CNC and mill-turn because the virtual CNC will not break. Virtual reality environment provided by EON studio software has been adopted in establishing the interactivity of a virtual CNC based on the geometry model constructed in off-the-shelf CAD software. Visual Basic was used in implementing the graphical user interface to operate the virtual CNC through the developed virtual controller. The virtual controller is in charge of (1) parsing user’s NC codes, (2) simulating the tool path of the parsed NC codes, and (3)driving the virtual CNC according to the tool path. The developed virtual CNC controller has been successfully applied in implementing virtual CNCs based on two physical three-axis CNC machines and has also been demonstrated in an international exposition successfully. The virtual controller can enable the virtual CNC in facilitating lecturing, tutoring, self-learning, and reducing the chances of accidental breakdown of precious CNC equipment.

Abstract: This study presents a new micromachine-based cell counting and sorting system capable of multi-wavelength detection for biological applications. Chip-based flow cytometers have been extensively investigated recently. Several unique features have been integrated on this new cell-analysis system. First, a series of new serpentine-shape pneumatic micro-pumps were used to drive sample and sheath flows and generate a hydrodynamic focusing effect. The control of fluids could be achieved with ease by using this approach. Multiple embedded optical fibers were then used to transmit the light source and collect induced fluorescence signals in and out of the chip device. Cells labeled with different fluorescent dyes could be then individually detected by corresponding fibers using lasers with different wavelengths. Finally, three pneumatic micro-valves downstream were used for cell sorting. The developed micro flow cytometer could be used for fast analysis of cell-related bio-medical applications.

Abstract: This paper proposes a novel microfluidic system for cell/microparticle recognition and manipulation utilizing a digital image processing technique (DIP) controlled optical tweezer under microfluidic configuration. Cell/microparticle samples are firstly electrokinetically sorted in a microfluidic channel and pass through an image detection region. Digital image processing technique is used to count and recognize the cell/particle samples and then sends control signals to generate laser pulses to manipulate the target cell/particles optically. The optical tweezer system is capable of catching, moving and switching the target cells within the microfluidic channel. The trapping force of the optical tweezer is also demonstrated utilizing the relationship between Stocks-drag force of microparticles and the applied electroosmotic flow. The proposed system provides a simple but high-performance solution for microparticle manipulation in a microfluidic device.

Abstract: Biochip is an emerging technology and has evoked great research interests in recent years. In this paper, a novel air-driven loop-type microfluidic biochip was investigated. Differing from conventional micro channels, this chip has a micro loop-channel and 3 sets of driving conduits with valveless design in their intersections so that the microfluid can be driven smoothly in unidirectional circular movements. The driving efficiency reaches the highest if the entry angle of driving conduits is in the tangent direction of the loop-channel. However, the smaller the included angle, the impact area the larger, leading to comparatively serious reflow phenomenon. Furthermore, the microfluid can be controlled to stop almost instantaneously in the loop segment. Therefore, this loop-type biochip is suitable for biochemical reactions under repeated multiple temperature operations such as polymerase chain reaction. A full circular movement completes a cycle of PCR amplification. Besides, this biochip has its merits including simpler chip design, shorter channel length, and flexible controllability for biochemical reactions.

Abstract: A citrate-stabilizing Au nanoparticles aqueous solution was prepared at near 0 oC by reducing tetracholoaurate(III) ions with sodium borohydride. Combining with Pluronic block copolymers, the citrate-stabilizing Au nanoparticles was nearly completely embedded in the mesoporous silica channels via fast silicification with silicate solution at near neutral pH. After calcination for removing organic templates, Au nanoparticles@mesoporous silicas of high surface area and pore volume were obtained. With different block copolymer, the pore size of the mesoporous silica can be tuned. The Au nanoparticles@SBA-15 mesoporous silica exhibits high catalytic activity to CO oxidation reaction.