Tiny injectable camera system to radically miniaturize endoscopes

Regular arrangement of doublet lenses directly fabricated on a CMOS image sensor. Credit: Timo Gissibl

At the University 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.

Colored SEM-image of a miniature triplet lens directly fabricated on an optical fiber. Credit: Timo Gissibl

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.”

Image of a multi-lens system with a diameter of 600 µm surrounded by four doublet lenses with a diameter of 120 µm. Credit: Timo Gissibl

Source: University of Stuttgart