This tiny camera can be injected with a syringe

University of Stuttgart researchers used 3D printing to fabricate a tiny three-lens camera that fits on the end of an optical fiber no wider than two human hairs. Eventually, the technology could lead to a new kind of very thin endoscope for looking inside the human body. According to the researchers, the camera delivered "high optical performances and tremendous compactness." From Phys.org:

(The camera) can focus on images from a distance of 3.0 mm, and relay them over the length of a 1.7-metre (5.6-foot) optical fibre to which it is attached.

The "imaging system" fits comfortably inside a standard syringe needle, said the team, allowing for delivery into a human organ, or even the brain.

"Endoscopic applications will allow for non-invasive and non-destructive examination of small objects in the medical as well as the industrial sector," they wrote (in their scientific paper).

Below, the lens (blue) was fabricated directly on the optical fiber (red). The fiber and camera are emerging from a hollow, 27 gauge syringe needle: