NASA Goddard Space Flight Center has developed a substantial advancement in additive manufacturing technology. The method eliminates most material restrictions, enabling fabrication of sub-microscale three-dimensional structures composed of nearly any material that is compatible with chemical vapor deposition (CVD) including metallic and ceramic materials. Current technology for the production of microscale three-dimensional structures, such as two-photon lithography, is generally limited to the use of photosensitive polymeric materials.
The technology capitalizes on existing stereolithography techniques to fabricate a polymeric scaffold of the desired three-dimensional structure employing a photosensitive polymer material. After the scaffold is complete, nickel can be deposited onto the structure using a catalyst and a low-temperature CVD process, at which point the polymer structure can be dissolved away, leaving a nickel shell. Using the resulting nickel shell as yet another scaffold, the desired material can be deposited using the appropriate CVD process since the melting point of nickel is 1455 °C. If necessary, the nickel can then be preferentially etched away.