Locally patterned anisotropy using grayscale vat photopolymerization

Additive manufacturing (AM), or 3D printing, has the ability to create complicated structures that cannot be produced using traditional manufacturing methods. However, these fabricated parts are usually created with only a single material, which limits the design flexibility. Many multi-material AM techniques have been proposed, but they usually lack the accuracy to achieve small-scale property control. Due to this limitation, it is difficult to 3D print structures with large degrees of anisotropy at a small scale without turning to metamaterials. In this work, we present a method to 3D print locally tunable anisotropic patterns using grayscale vat photopolymerization. This method allows for widely tunable degree and orientation of anisotropy. Moreover, this vast property control requires only one resin feedstock, which allows us to preserve the high accuracy and high efficiency of vat photopolymerization printing when creating these structures. The patterns used in this work are proven to be effective at multiple length scales and when used together to create composite structures with locally varying anisotropy.