A feasibility study on process monitoring and control in vat photopolymerization of ceramics

Vat photopolymerization is a prominent additive manufacturing technology for the fabrication of near-net shape ceramic parts. To serve the high tech industry's needs, additive manufacturing equipment has to scale up to larger product sizes and higher, repeatable product quality. This motivates the integration of more process monitoring and control solutions into the equipment. Hence, this paper reviews the state of the art in process modelling, sensing, actuation and control for ceramic vat photopolymerization. The aim is to analyze the feasibility of potential real-time control schemes for the vat photopolymerization process. A comparison of time scales related to physical phenomena in vat photopolymerization, sampling rates of sensors, and response times of actuators, shows that feasibility of real-time control is governed by sensor sampling rates. With the current state of sensor technology, real-time control is only feasible in mask projection systems. Alternatively, one can resort to layer-to-layer control schemes.