This Small Business Innovation Research (SBIR) Phase II project is directed towards the development of an ultrahigh speed micro-spindle for micro-machining. The proposed spindle for micro-milling and micro-grinding at speeds near 500,000 rpm will be implemented with existing commercial micro-machining systems. Micro-manufacturing refers to the creation of high-precision three-dimensional (3D) products using a variety of materials and possessing features with sizes ranging from tens of micrometers to a few millimeters. While micro-scale technologies are well established in the semiconductor and microelectronics fields, the same cannot be said for manufacturing products involving complex 3D geometry and high accuracies in non-silicon materials. The trends in industrial and military products that demand miniaturization, design flexibility, reduced energy consumption, and high accuracy continue to accelerate -- especially in the medical, biotechnology, telecommunications, and energy fields. The principal advantages of the proposed micro-spindle include higher production rates and precision obtained through the implementation of ultrahigh speed machining that will decrease the cutting forces and tool vibrations. The prototype micro-spindle will be evaluated in a series of alpha and beta testing with commercial micro-machining systems. The objective of Phase II is to perform the necessary R&D to prepare the micro-spindle for marketing.<br/><br/>The broader impact/commercial potential of this project encompasses the following. The ultrahigh speed micro-spindle will enable the production of cost-effective micro-components and will positively impact the micro-fabrication industry. Since the underlying scientific principles of micromachining at such high speeds are not known, the availability of the proposed spindle will allow for basic studies to uncover the response of materials under these conditions. Such basic information could lead to new scientific discoveries and further extend the micromachining processes. The data and information generated will undoubtedly be used in future for training of graduate students. The broad impact of this research includes expansion of micromanufacturing research, and research opportunities for next-generation scientific researchers and technology developers to pursue micro machining and micro manufacturing related efforts in the broader fields of micro positioning devices, micro die-and-mold manufacturing, micro sensing and monitoring systems, and micro factory integrations and optimization. Commercialization of the proposed micro-milling spindle will be instrumental in the development of new businesses and industries, and high value added jobs.