Papers by Author: Pai Shan Pa

Abstract: This study describes a new precise recycle module as a clean poduction pocess and an environmental protection consideration that uses micro electroetching (MECE) and a new design of an intercross tool to remove defective transparent conducting oxide (TCO) nanostructures from the optical PET diaphragm surfaces for e-paper surface. This process takes very little time to remove the TCO easily and cleanly and is highly efficient both technically and economically. A large diameter of the cathode of the intercross tool combined with a small gap between the cathode and the workpiece corresponds to a higher removal rate of TCO. This higher feed rate combined with enough voltage results in a shorter machining time. A high rotational speed of the intercross tool can also improve dregs discharge and allows a higher feed rate of the optical PET. A small end radius of the cathode or a thin cathode of the bulge-form tool takes less time for the same amount (20 nm) of TCO removal.

Abstract: A newly devised process using round bar-shaped electrodes and ultrasonic enhancement in a micro-electrochemical machining (UMECM) process is described. The purpose is the precise removal of In₂O₃SnO₂ thin-film nanostructures from optoelectronic flat panel display color filter surfaces. In the current experiment it was found that a large surface area cathode and a small gap-size between the cathode and workpiece was found to remove the In₂O₃SnO₂ rapidly. A high feed rate of the workpiece (the display with color filter) and adequate electrical power results in fast machining. Pulsed direct current improves dregs discharge and this is an advantage with a fast feed. A high electrode rotational speed also corresponds to faster removal of the In₂O₃SnO₂ nanostructures. The development of the proposed precision production design is based on both technical and economic considerations.

Abstract: The motion system of a toy robotic snake is discussed. This study is expected to provide the best design for this toy and to help widen future application. A mathematical model was constructed after a literature and mechanical design survey. Tribotix AI 1001 motors are used to operate the snake. By an analysis of the mathematical model, transformation of the D-H matrices, and the introduction of forward and inverse kinematics, the relationship between the angle and the coordinate of each section of the robotic snake were determined. The trace curve of a real snake was also studied to arrive at a description of the motion and parameter changes for the robotic snake within a single time unit. MATLAB was used for the simulation and to plot the figures. Experiments and trace analyses were also performed to obtain the design rule and an approach to an improved mechanism for the toy robotic snake. Finally, the experimental results and the possibility of future development are discussed.

Abstract: A effective method for the precision electrochemical removal of thin film nanostructures from LCD panels using a gear-shaped electrode tool has been developed. This ultra-precise process effectively removes defective Indium-Tin-Oxide layers allowing LCD panels to be returned to the production line and significantly reduces costs. In the current experiment a 7th Generation TFT-LCD panel was used. A high rotational speed of the gear-shaped negative electrode elevates discharge mobility and improves the removal effect. Pulsed direct current can improve the effect of dregs discharge and is advantageous when combined with a fast workpiece feed rate. A fast feed combined with a high current flow results in very effective removal of the color filter layer. A negative electrode of large diameter with a small edge radius provides higher current density and also improves the removal affect. This novel design using electrochemical removal as a precision recycling process for removing ITO layers from LCD panels is clean, effective and very fast.

Abstract: This study describes a new module that uses micro electrochemical machining, and a new design of a convex-shaped tool, in a precision reclamation process to remove defective Indium-tin-oxide (ITO) nanostructures from the optical PET diaphragm surfaces of a digital-paper display. This process takes very little time to remove the ITO layers easily and cleanly and is highly efficient both technically and economically. A small end radius of the cathode or a thin cathode of the bulge-form tool takes less time for the same amount (20 nm) of ITO removal. A large diameter of the cathode of the bulge-form tool combined with a small gap between the cathode and the workpiece corresponds to a higher removal rate of ITO. A high rotational speed of the bulge-form tool can also improve dregs discharge and allows a higher feed rate of the optical PET diaphragm. This higher feed rate combined with enough voltage results in a shorter machining time.

Abstract: This paper studies the performance assessment of magnetic-assistance electrochemical finishing using an effective design system and magnetic force to the electrolyte to assist the dregs discharge on zinc alloy beyond die casting by electrochemical finishing as a finish process on the freeform surface of castings. An outer shell of toy vehicle is taken for instance in the experiment. A small distance between the two magnets or large magnetic field intensity provides larger magnetic force and discharge ability. A higher current rating with magnetic-assistance can avoid the difficulty of dreg discharge, thus reducing the finish time. Pulsed direct current can slightly promote the finishing effect, but the machining time is increased. Thus the magnetic-assistance electrochemical finishing without pulsed current is recommended for the finish process. It is a great contribution that the magnetic-assistance electrochemical finishing just needs quite short to make the freeform surface of workpiece smooth and bright.

Abstract: The design of the biped toy robot in this study, presents a brand new concept compared to that of the conventional mechanical biped robots on the market. These conventional mechanical products rely mainly on a large sole area to stabilize the wobbling movement during walking. In this design walking stability is not achieved by large sole areas, but by having more degrees of freedom and automatically shifting the center of gravity as the robot walks. A single motor is used to drive the biped toy robot trunk so that the center of gravity is automatically shifted to achieve walking stability. The two feet are driven by four connecting rods for striding and leg-lifting action. More particularly, an equal parallel crank mechanism is provided that uses a single motor to drive the connecting rods, thereby swinging the center of gravity of the toy robot in time with striding frequency. In addition, the concept of the zero moment point is utilized in the shifting of the center of gravity allowing the biped robot to lift its legs, change step, and move forward in balance. This study also discusses the use of the four connecting rods, and the shifting of the center of gravity of the robot, as an alternative to the servomotors commonly used in conventional robots which are bulky, expensive and hard to control.

Abstract: A system design for a recycling process for the nano removal of the indium tin oxide (ITO) nanostructure from the color filter surface of TFT-LCD displays is presented. The low yield rate of ITO thin-films is well known in semiconductor production processes. By establishing a recycling process for the ultra-precise removal of the thin-film nanostructure, the optoelectronic semiconductor industry can effectively recycle defective products with a reduction of both production costs and pollution. In the current experiment, the major interest lies in the features of the technology and the design of an oblique cathode for the electrochemical removal process. For this process a steep gradient of the oblique cathode provides large discharge mobility and a better removal effect. A thin oblique cathode, a small gap-width between the cathode and the ITO surface, or a high flow rate of electrolyte corresponds to a higher removal rate of the ITO-layer. A large current flow combined with a high feed rate of the display also results in a fast removal rate.

Abstract: A new triangular-shape designed tool as a cathode in microelectromechanical etching process is a precision nanoscale production of a reclamation system of Indium tin oxide (ITO) thin-films defects removal from optoelectronic flat panel displays’ color filter surface is demonstrated in the current study. Through the ultra-precise removal of the thin-film nanostructure, the optoelectronic semiconductor industry can effectively reclaim defective products, reducing production costs. In the current experiment, a large size triangular shape cathode is accompanied by a small gap-width between the cathode and the workpiece takes less time for the same amount of ITO removal. A higher feed rate of displays’ color filter or a small end radius of the cathode combined with enough electric power produces fast machining. Pulsed direct current can improve the effect of dregs discharge and is advantageous in association with a fast workpiece feed rate. However, it raises the current rating. A large flow rate of the electrolyte corresponds to a higher removal rate for the ITO nanostructure. The electrochemical etching just needs a short time to make the ITO remove removal easy and clean.

Abstract: The current study presents a method for finishing hole-wall surfaces, superior to that obtainable by traditional boring, using a simultaneous grinding and electropolishing process. A specially designed finishing tool, that includes a nonconductive grinding wheel and an electrode is employed in the process. The form of the tool and the machining process are different from those used in electrochemical grinding (ECG). A high power electrical supply is not required with this design of finishing tool because the axial feed allows for the use of a smaller interactive area between the electrode and the hole wall surface. The experimental results show that a high current flow combined with a fast axial feed rate for the tool is an important advantage to the finishing process. The finishing effect is better with high rotational tool speeds because discharge of the electropolishing dregs and grinding cuttings becomes more efficient and this is also advantageous to the grinding finishing process. Pulsed direct current can slightly improve the electrochemical finishing effect, but machining takes longer and this raises costs. A small edge radius on the electrode also provides more than sufficient discharge and gives a better finish. We intend to make a complete evaluation of the processing parameter data so that the use of this method for hole-wall surface finishing may be extended in the future. The combined application of grinding and electropolishing is crucial to this method and the specially designed tool and the new finishing process are highly efficient and inexpensive.