Advanced Materials

Composites are typically made from layers of multiple materials, or have a matrix structure consisting of fibers or particles embedded in a surrounding medium. In many applications, such as parts for airframes, they are in addition required to be built in complex freeform shapes. It's interesting to speculate that if additive fabrication hadn't already existed, it might have been necessary to invent some form of it simply to move the development of this important field forward.

A Two-way Street
Composites also share a unique symbiotic relationship with additive fabrication. Rapid prototyping has been routinely used to make tooling and templates to manufacture composites - and now RM is being used to make the final products themselves. Conversely, many of the newest and most advanced materials used in RP, and therefore RM, are based on composite material technologies. Composites improve and extend properties by taking advantage of the favorable characteristics of each constituent material. This makes it easier to improve the mechanical or thermal properties of a photopolymer, for example, without placing the entire burden on a molecular chemistry solution. The benefits obtained from combining materials are also usually multiplicative rather than simply additive. That's probably one reason that nature so frequently uses such materials as optimized solutions to evolutionary problems. Nearly every structure in biology is a composite of one kind or another.

Automating Manufacturing and Expanding Capabilities
RM provides the means for automating the manufacturing of advanced materials. It also extends their functionality through the use of graded and mixed materials and optimized local architecture. These are important reasons why metal-matrix composites, and parts for aerospace are among the most active materials applications being investigated. The ability to make a part from disparate ingredients like ceramics and metals means that previously unattainable levels of functionality and efficiency can be achieved. This can be expected to have a big impact on any application where a significant improvement in the performance of functional parts is important, such as internal combustion engines and other high speed mechanisms.

New commercial aircraft designs use a sharply increasing number of composite parts. Indeed, the new Boeing 787 will be largely built from composites and will rely on them for its competitive edge. Consequently, methods which automate previously labor-intensive operations for making these parts are becoming very important. The fate of Boeing will likely hinge on the market acceptance of the 787 - and that market acceptance will be determined by reaching engineering and economic goals directly tied to the use of composites.

Probably the most exciting thing about the use of RM in manufacturing advanced materials is the range of applications being considered. Among them are superconductor composites, multi-functional structures to provide load bearing and measurement functions, sound dampening and insulation systems, catalyst and reactor structures, nanofiber-reinforced polymers - and many more specialized materials.

Combining this diversity of materials with an equal or greater number of functional applications for rapid manufacturing points to a future filled with highly-refined, complicated products designed to provide utility from almost the molecular level on up.