Photogrammetric measurements of 3D printed microfluidic devices

Additive manufacturing (AM) processes are being more frequently applied in several fields ranging from the industrial to the biomedical, in large part owing to their advantages which make them suitable for several applications such as scaffolds for tissue engineering, dental procedures, and 3D models to improve surgical planning. Moreover, these processes are particularly suited for the fabrication of microfluidic devices and labs-on-a-chip (LOC) designed to work with biological samples and chemical reaction mixtures. An aspect not sufficiently investigated is related to the dimensional verification of these devices. The main criticality is the texture-less surface that characterizes the AM products and strongly affects the effectiveness of most currently available 3D optical measuring instruments. In this study, a passive photogrammetric scanning system has been used as a non-destructive and low-cost technique for the reconstruction and measurement of 3D printed microfluidic devices. Four devices, manufactured with stereolithography (SLA), fused deposition modelling (FDM) a Stratasys trademark, also known as fused filament fabrication (FFF), and Polyjet have been reconstructed and measured, and the results have been compared to those obtained with optical profilometry that is considered as the gold standard.