tailieunhanh - Crc Press Mechatronics Handbook 2002 By Laxxuss Episode 1 Part 10

Tham khảo tài liệu 'crc press mechatronics handbook 2002 by laxxuss episode 1 part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | that the spherical-conical micromotors develop higher electromagnetic torque compared with the con- ventional design. In addition improved cooling reduced undesirable torques components as well as increased ruggedness and robustness contribute to the viability of the proposed solution. Thus using the classifier paradigm novel microdevices with superior performance can be devised. MEMS Fabrication Microelectromechanics which integrates micromechanics and microelectronics requires affordable lowcost high-yield fabrication technologies which allow one to fabricate 3-D microscale structures and devices. Micromachining is a key fabrication technology for microscale structures devices and MEMS. Microelectromechanical systems fabrication technologies fall into three broad categories bulk machining surface machining and LIGA LIGA-like techniques 1-3 . Bulk Micromachining Bulk and surface micromachining are based on the modified CMOS and specifically designed micromachining processes. Bulk micromachining of silicon uses wet and dry etching techniques in conjunction with etch masks and etch-stop-layers to develop microstructures from the silicon substrate. Microstructures are fabricated by etching areas of the silicon substrate to release the desired 3-D microstructures. The anisotropic and isotropic wet etching processes as well as concentration dependent etching techniques are widely used in bulk micromachining. The microstructures are formed by etching away the bulk of the silicon wafer to fabricate the desired 3-D structures. Bulk machining with its crystallographic and dopant-dependent etch processes when combined with wafer-to-wafer bonding produces complex 3-D microstructures with the desired geometry. Through bulk micromachining one fabricates microstructures by etching deeply into the silicon wafer. There are several ways to etch the silicon wafer. The anisotropic etching uses etchants that etch different crystallographic directions at different rates. Through