Weighting Method to Increase Print Fidelity of Filtered Back Projection Volumetric Additive Manufacturing Around Complex Inserts

The embedding of inserts such as electronics within polymer materials is required in many applications in order to manufacture sensors and actuators. In case-specific and patient-specific applications and in temperature-sensitive inserts, the use of inject molding is not possible and additive manufacturing is required. Moving parts and the layer-by-layer process of common additive manufacturing methods limit the insert and print shapes which are feasible. Volumetric additive manufacturing (VAM) has recently been introduced as a new method of 3D printing in which calculated images of light are projected into a rotating vial of resin. This method provides the capability of printing over objects and inserts such as electronic boards. In this study we aim to improve print fidelity when using the Filtered Back Projection method to calculate projections. To this end, a weighting technique is proposed in which various parts of the print model are assigned weights based on the number of directions from which they receive light. Simulations show that this technique results in more uniform print models, lower out-of-part dose and an increase in dose received by the print model.