They 3D printed a three-part lens using something called a “femtosecond direct laser writing system,” which is no bigger than a grain of salt, onto the end of a fiber optic cable the width of two human hairs. “Endoscopic applications will allow for non-invasive and non-destructive examination of small objects in the medical as well as the industrial sector,” its creators wrote in their paper. They added: “The unprecedented flexibility of our method paves the way towards printed optical miniature instruments such as endoscopes, fibre-imaging systems for cell biology, new illumination systems, miniature optical fibre traps, integrated quantum emitters and detectors, and miniature drones and robots with autonomous vision.” The researchers say that during testing it produced “high optical performances and tremendous compactness.” Once inside the body, 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, allowing for delivery into a human organ, or even the brain, said the team. What is remarkable about the tiny camera that it takes very little effort to make these lenses. The researchers say that they designed, built, and tested the tiny camera in just a few hours. The process was described in the journal Nature Photonics.
