tailieunhanh - Mechatronics for Safety, Security and Dependability in a New Era - Arai and Arai Part 7

Tham khảo tài liệu 'mechatronics for safety, security and dependability in a new era - arai and arai part 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 164 INTRODUCTION In recent years many kinds of metals are applied to medical usages instead of ceramics high polymer and so on. Metals have the advantage in terms of strength elasticity and stiffness. Usually employed metals are stainless steel cobalt-chromium alloy titanium gold and so forth. Naturally these metals are widely employed as materials of such medical implements as are buried in human bodies for example fixture for fracture artificial joints tooth implants and others. Accordingly it is important to investigate the influences or toxicities of the metals for human bodies. For satisfactory selection of metals used in the medical implements therefore it is essential to evaluate bio- and blood- compatibilities of the metals. Conventionally the evaluation has been done by making experiments on living animals which consumes a lot of money and time. To save the cost it is required to develop a new evaluating method. On the other hand micro-rheology device to measure blood-fluidity has been developed to investigate flow mechanism of blood. The device allows human blood flow to pass through microchannel array built on a chip which is a model of capillary vessels due to its shape in which many microgrooves are arranged in parallel. At the same time the blood flow through the microchannel array can be visually observed which can evaluate its fluidity. Consequently the employment of microchannel array chips made of various metals is expected to evaluate the compatibility between blood and metals. However the microgrooves constituting a microchannel array is generally built on silicon by photolithographic techniques which do not have high abilities to control the shape of the microgrooves and to increase the accuracy of the shape. Their shape and accuracy are extremely important to measure blood-fluidity with a microchannel array chip. Accordingly the study aims at fabrication of the microchannel array chip by ultraprecision cutting. Cutting can make complicated .