3D printing aids in understanding food enjoyment

UNIVERSITY PARK, Pa. Tasting food relies on food volatiles moving from the back of the mouth to the nasal cavity, but researchers have wondered why airflow doesn't carry them in the other direction, into the lungs. Now a team of engineers, using a 3D printed model of the human airway from nostril to trachea, has determined that the shape of the airway preferentially transfers volatiles to the nasal cavity and allows humans to enjoy the smell of good food. "During quiet breathing, there is no valve that can control the direction of volatile transport," said Rui Ni , assistant professor of mechanical engineering , Penn State. "However, something must be controlling the movement of these particles and keeping them out of the lungs." In the past, physiologists looked at the nasal passages, but not at the pathway from the back of the mouth to the nose. In this case, the researchers used data from CT scans and the help of two radiologists to build a schematic of the human airway from the nostrils to the trachea, including the fine structure. They then used the schematic to make a 3D model using a 3D printer.