NSF Award
8660931
This proposal involves the development of a new technique for the generation of complex three-dimensional structures directly from a CAD/CAM database without the need for molds or subsequent machining. The innovation will use independently targeted particles of molten metal or composite metal to build structures under computer control in much the same manner that an ink-jet printer produces images. The structure would be constructed by "writing" multiple cross sections. Cohesion between particles would be provided by cold welding or rapid solidification. Cemented carbides, stainless steels and aluminum-based eutectic alloys appear best suited for use in this method. The basic innovation has two major subsections: the material injection system and the material delivery system. The Phase I research will study various means of accomplishing the two major subsections, the appropriate materials to use, the material properties to be imparted, and the applications to be addressed. Mathematical models of the various components will be developed to gain a quantitative understanding of the process parameters and interaction between the individual components. The results should provide theoretical groundwork and a clearly defined approach for follow-on research. Follow-on research plans include developing a complete engineering design of the system and construction of a working prototype. This research should lead to a method to generate net shape parts with unique properties directly from a CAD/CAM database. Application should be to various industries including aerospace, electronics and machine tools. Method should result in decreased lead time and increased productivity. *** 8707870 Tsach This proposal will investigate a novel robot hand which utilizes rubber fingers which bend to grasp an object when their internal pressure is elevated. The bending of the fingers is accomplished by employing non-uniform wall thickness in the fingers, and the bending mechanism is controlled by a single variable (the internal pressure). Using rubber actuators (fingers) drastically reduces the number of control variables of the artificial fingers without restricting its maneuverability. The novel robot hand should be capable of gripping objects of various shapes and sizes, applying various grasping modes, modifying the compliance of the grip, and performing limited object manipulations. Preliminary work has shown this approach to be attractive. The proposed research will investigate a design to enable the base angle of each finger to be controlled independently which should significantly enhance the object manipulation capabilities of the hand. The incorporation of tactile sensing to control the contact forces and gripping compliance will also be investigated. This work is needed to determine the feasibility of these two tasks, which, if successful, can lead to development of a versatile, multiple grasping robotic hand. This novel robot hand should be a far less complex mechanism than other current approaches, and hence should contribute to improved production efficiency.
