At the Univesity of Stuttgart in Germany, scientists have created a lens system small enough to be injected through a syringe. It can be attached to the distal end of a fiber optic cable, while at the proximal end a tiny CMOS sensor captures the images.
The hope is that the technology will lead to flexible endoscopes that can be
delivered into the body through tiny portholes to peek inside without
causing too much damage.
The lenses are manufactured using 3D printing, with the initial design and simulation happening on the computer before the real things are produced. The focal point is only 3mm away from the lenses and having a width of only 100 micrometers will allow for imaging of difficult to reach and detailed anatomical structures.
The researchers published their study in journal Nature Photonics, in which they “demonstrate the complete process chain, from optical design, manufacturing by femtosecond two-photon direct laser writing and testing to the application of multi-lens objectives with sizes around 100 µm, and validate their high performance and functionality by quantitative measurements of the modulation transfer function and aberrations.”
It took only a few hours to design, manufacture and test the tiny eye, which yielded “high optical performances and tremendous compactness,” the researchers reported.
It 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.
The compound lense can also be printed onto image sensor other than optical fibres, such as those used in digital cameras. The compound lens is just 100 micrometres (0.1 millimetres or 0.004 inches) wide, and 120 micrometres with its casing.