Use of volumetric additive manufacturing as an in-space manufacturing technology

Computed Axial Lithography (CAL) is a recent advancement in volumetric additive manufacturing (VAM) that delivers a light dose to a photopolymer volume through tomographic reconstruction. The precursor liquid or gel itself generally supports the emerging object, eliminating the need for wasteful dedicated solid supporting structures. A challenge, however, is that desired geometry can shrink or expand during solidification and on Earth, if the precursor material's viscosity is low enough. These effects may result in sinking or floating of the component, which can blur the geometry.In principle, CAL is promising for in-space manufacturing because, unlike layer-based processes, CAL does not require a flat liquid-gas interface to be maintained during printing. With suitable development, CAL is potentially capable of manufacturing parts such as organic tissue, flexible seals, rigid trusses, and microstructures for space exploration, as well as repairing existing tools and parts. 'SpaceCAL' flew on a microgravity parabolic flight in May 2022 to demonstrate the capabilities of CAL and analyse a CAL system in a microgravity. Initial findings show that 0.12 Pa-s low viscosity precursor can be printed in microgravity with less geometric distortion than an Earth-based gravity counterpart.

Automated summary

Computed Axial Lithography (CAL) is a recent advancement in volumetric additive manufacturing that uses tomographic reconstruction to deliver a light dose to a photopolymer volume. It eliminates the need for dedicated solid supporting structures and has the potential to manufacture various parts for space exploration and repair existing tools and parts. Initial findings from microgravity flight tests show that low viscosity precursor can be printed with less geometric distortion compared to Earth-based gravity printing.