Cooling strategies for embedded electronic components of wearable computers fabricated by shape deposition manufacturing

Rugged, portable computers that can be comfortably worn on the body and easily operated for maintenance applications are being designed and manufactured at Carnegie Mellon University. The recently developed process of Shape Deposition Manufacturing has created the opportunity to embed the electronics of wearable computers in a polymer composite substrate. As both a protective outer case and a conductive heat dissipating medium, the substrate satisfies two basic design constraints of wearable computers: design for ruggedness and cooling efficiency. One such application of embedded electronics is the VuMan3R, a wearable computer designed for aircraft maintenance. To understand thermal phenomena of embedded electronic design, a combination of spectral element numerical simulations, physical experimentation, and analytical models facilitate the exploration of the thermal design space. Numerical models with heat spreaders, air channels, and various substrate materials test the thermal performance, while physical experimentation of an embedded electronic artifact ensures the accuracy and practicality of the numerical simulations. Analytical models using thermal resistance networks are created to predict heat flow paths within the embedded electronic artifact as well as the role of conductive fillers used in polymer composites.