PITA Fiscal Year 2007 Projects


Feasibility of a Novel Technique for Fabrication of Micro/Nano-Scale Spheres and for Multi-Scale Layered Manufacturing from Metals and Polymers
This project focuses on development and utilization of a microfluidics-based technique as a means (1) to create micro/nano-scale metal and polymer spheres and (2) to perform solid free-form manufacturing of multiscale (nano-to-micro) components. The concept involves utilizing a microfluidic device that takes advantage of the Rayleigh capillary instability to break up a continuous flow of fluid into micro/nano-scale droplets. In this proposal, we will investigate the feasibility of applying this technique to create molten metal or polymer droplets. This requires development of a system that will function at temperatures higher than the melting temperature of the metal (or polymer), design and fabrication of a high-temperature microfluidic device, selection of proper operating conditions, and integration of the overall system. The droplets of molten material can be either directly used, or cooled down to obtain solid micro/nano-sized spheres of metals or polymers. Although Rayleigh capillary instability has been utilized in ink-jet technology and demonstrated with liquids like oil and water at room temperature, the high-temperature application and use of the process for creating nano-scale metal and polymer droplets has not been previously addressed in literature.

There are various aspects of the proposed technique that make it attractive with respect to other existing techniques. The system will be capable of creating micro and nano-scale droplets (and spheres) of metals and polymers with highly controllable size and a high level of sphericity. A wide range of droplet sizes (spanning two orders of magnitude) can be generated using a single device geometry. These attractive aspects translate into various advantages for at least two exciting applications of the system, including (1) multiscale (nano-to-micro) manufacturing through solid freeform fabrication, and (2) fabrication of metallic and polymer spheres for creating near-net-shape components through molding/compaction and layered manufacturing techniques.