See how the bacteria inside the 3D printed masks painted them in different colors.

The researchers called their development hybrid living material. To create it, scientists used two

types of resins - a regular 3D printing material that hardens after the part is created, and a temporary resin that forms cavities inside the part.

The researchers injected chemicals into these cavities.solution with fluorescent bacteria. A few hours after the part was printed, microbes began to glow different colors in parts of the object printed from the temporary material.

The glow is associated with substances that were contained in a chemical solution - they cause certain reactions in bacteria, causing them to glow in different colors.

Researchers note that future technologycan be used to create biomedical devices, smart packaging that detects bacterial contamination, and other surfaces that respond to environmental signals.