Three dimensional (3D) forces are the key factors for determining movement of teeth during orthodontic treatment. Designing precise forces and torques on tooth before treatment can result accurate tooth movements, but it is too difficult to realize. In orthodontic biomechanical systems, the periodontal tissues, including bones, teeth, and periodontal ligaments (PDL), are affected by braces, and measuring the forces applied on the teeth by braces should be based on a simulated model composed of these three types of tissues. This study explores the design and fabrication of a simulated oral model for 3D orthodontic force measurements. Based on medical image processing, tissue reconstruction, 3D printing, and PDL simulation and testing, a model for measuring force was designed and fabricated, which can potentially be used for force prediction, design of treatment plans, and precise clinical operation. The experiment illustrated that bi-component silicones with 2:8 ratios had similar mechanical properties to PDL, and with a positioning guide, the teeth were assembled in the mandible sockets accurately, and so a customized oral model for 3D orthodontic force measurement was created.

Heat generated during wire saw slicing can cause silicon temperature raise and make silicon wafer warpage, especially for larger silicon wafers. In order to study the wire saw effect on silicon temperature during slicing process, three kinds of wire saw, mainly semi-fixed abrasive wire saw and traditional wire saw, are applied for slicing silicon ingot. In this paper, the thermocouple is used to measure the temperature of the silicon during wire saw slicing. The experiment results show that the temperature of the silicon increases along with the wire saw working direction and reaches maximum value near the outlet position of silicon. The temperature of the silicon sliced by semi-fixed abrasive wire saw is lower than that sliced by traditional wire saw.

In this study the prediction of the erosion profiles during ECM of the spiral hole was presented. By assumptions, the major points were simplified into one-dimensional problems. The theoretical and computational model was built to illustrate the profile movement as the time elapses. The analysis was based on the law of electrolysis and the software MATLAB was used. Verifications were done through experiments and the deviation was 7.5% between theoretical and experimental result. On the basis of the prediction of the erosion profile, the applied parameters could be estimated.

Electrochemical machining (ECM) technology has the advantage of machining the workpiece with complex profile on the basis of electrolysis. In this study, turbulated holes with the rib’s shape of spiral and annular were processed by ECM by using the shaped cathodes. Experimental system was built which consists of electrolyte supply module, power supply unit and workpiece holding device. Machining experimentations were carried out on the built system. Analysis and discussions were done according to the experimental results. It indicated machining efficiency is high by using the shaped cathode. Machining error could be controlled within 10-20%.

Fixed-abrasive diamond wire saw is widely used for slicing semiconductor materials. In this paper, a novel manufacturing method is studied by using polyethylene wire to replace the traditional metallic core wire. A new coating device of ultraviolet-curing for rapidly making diamond wire saw is developed. In terms of tensile strength experiments’ results, a high strength polyethylene multi-strand wire is finally selected as the core wire of the fixed-abrasive wire saws. Experimental results show that the high tensile strength of polyethylene multi-strand wire can satisfy the technical requirements of fixed-abrasive wire saws.