Tham khảo tài liệu 'the mems handbook mems applications (2nd ed) - m. gad el hak episode 1 part 9', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Sensors and Actuators for Turbulent Flows 6-61 FIGURE An external manipulator is used to fold and supply the structure with a reshaping voltage. The Joule s heating raises the temperature of the arm to cause annealing effect which results in stress release and plastic deformation. After removal of the voltage the arm cools down and the structure retains its three-dimensional shape. Reprinted with permission from Fukuta Y. Akiyama T. and Fujita H. 1995 A Reshaping Technology with Joule Heat for Three-Dimensional Silicon Structures Technical Digest Inter. Confer. on Solid-State Sensor and Actuator Tranducers 95 pp. 174-177 25-29 June Stockholm Sweden. FIGURE Illustration of a three-dimensional self-assembled polysilicon structure based on scratch-drive actuators. Reprinted with permission from Akiyama T. Collard D. and Fujita H. 1997 Scratch Drive Actuator with Mechanical Links for Self-Assembly of Three-Dimensional MEMS J. MEMS 6 pp. 10-17. makes it possible to control the final bending angle rather well. A reversible bending angle can be obtained as a result of the thermal expansion of the cured polyimide. A metal conductor is used as a resistive heater which produces local power dissipation in the joint. A temperature increase results in an expansion of the polyimide and a dynamic change in the bending angle. 2006 by Taylor Francis Group LLC 6-62 MEMS Applications b 2w a c Moveable part d FIGURE Production of a three-dimensional structure with Si mechanical parts based on surface tension forces top figure and SEM photo of the resulting three-dimensional structure bottom figure . Reprinted with permission from Syms . 1998 Demonstration of Three-Dimensional Microstructure Self-Assembly Sensors and Actuators A 65 pp. 238-243. Microturbomachines Micropumps There have been several studies of microfabricated pumps. Some of them use non-mechanical effects. The so-called Knudsen pump uses the thermal-creep effect to move rarefied gases from .
