3D necroprinting: Mosquito proboscis as a biological micro nozzle for 3D printing

Researchers at the University of Houston have developed a 3D printing process that uses the proboscis of female Aedes aegypti mosquitoes as a natural micro nozzle. The technique, which they call 3D necroprinting, is aimed at high-precision direct ink writing applications with extremely fine structures in the micrometer range. What is particularly interesting for the additive manufacturing community is that a finished biological component takes on the role of elaborately manufactured metal or glass nozzles.

Before choosing the mosquito proboscis, the team analyzed numerous natural microstructures, including insect stingers, snake fangs, and plant vascular bundles. The proboscis of female mosquitoes proved to be particularly suitable because it is slender and largely straight, with an internal diameter of about 20 to 25 micrometers. This allows line widths of around 20 micrometers to be achieved, which exceeds conventional 36-gauge metal tips. The stiffness is around 200 megapascals, which is similar to that of common plastics. In addition, the structure can withstand internal pressures of up to 60 kilopascals.

For use in 3D printing, the researchers mounted the prepared suction nozzle on a specially designed direct ink writing printer. 3D-printed scaffolds mechanically stabilize the biological nozzle. In experiments, the system extruded various bioinks and produced complex geometries such as a honeycomb pattern, a stylized maple leaf, and a bioscaffold with living cancer cells and red blood cells. More than 86 percent of the cells survived the printing process, indicating comparatively low shear forces in the nozzle.

In addition to print quality, the approach also addresses cost and sustainability issues. According to the study, conventional metal or plastic microdispenser tips cost up to $80 each. The mosquito nozzle, on the other hand, is made from sterile cultured material and can be manufactured for less than $1. The cost per proboscis is approximately $0.80. The biological tip remains functional for up to one year when stored frozen. However, the price comes at the expense of pressure resistance, as the mosquito nozzle fails at around 60 kilopascals, while borosilicate glass tips tolerate pressures of over 20,000 kilopascals.

The authors see 3D necroprinting as a step toward biohybrid manufacturing, in which non-living biological structures replace technical components. Future work could investigate other insect structures, such as the proboscis of predatory bugs, tsetse flies, or aphids, to expand the range of biological micro-nozzles available for 3D printing.