Development of strategies and advanced tools for complex micromanipulation.

摘要

Advanced micromanipulation tools and strategies for micro-assembly can significantly enhance the development of miniaturized systems and devices for many potential applications. Desirable characteristics of such tools include a high degree of manipulation dexterity for carrying out complex micromanipulation tasks as well as small device sizes for potentially enabling large-scale micromanufacturing applications. There are various limitations in achieving such micro-assembly using existing devices and techniques for micromanipulation. These include large sizes, limited functionality and dexterity of the devices as well as the presence of unconventional effects such as electrostatic, capillary and van der Waal's forces that tend to adversely influence contact manipulation tasks at the micro-scale. In order to address some of these issues, three strategies of complex micromanipulation for micro-assembly are developed in this thesis. The scope of the work includes modeling, development and experimentation of novel tools and techniques towards accomplishing these strategies.;The first strategy involves the development of theoretical models as well as a chip-scale micromanipulation tool to enable multi-part micro-assembly. This is achieved by using the coordinated action of multiple micro-fingers of the tool to simultaneously grasp, move and align micro-objects within a designated workspace. The second strategy presented in this thesis involves the development of a chip-scale microgripping tool that can achieve stable, multi-point grasps on arbitrarily shaped micro-objects using a single rectilinear actuator. Such grasps are highly beneficial in micro-assembly applications that require immobilization of micro-objects such as object-fixturing and long-range transport of objects or object-assemblies. The third strategy enables the critical task of object regrasp (changing points of grasp on an object) at the micro-scale without the need for intermediately releasing the micro-object on a substrate. Accomplishing regrasp in such a fashion is highly beneficial as releasing a grasped micro-object can be very challenging at the micro-scale due to the presence of adhesive forces that cause the object to strongly adhere to the endeffectors of the micromanipulator. The seamless micro-regrasp task proposed in this thesis involves inducing smooth sliding of a grasped micro-object by providing controlled vibrations to one or more of the endeffectors in contact with the micro-object.