Towards 3D printed confocal endoscopy

Abstract

A low-cost confocal endoscope was developed consisting of a 3D printed laser scanner, a lens, and a housing. The developed tool, mainly made out of low cost polymer offers a disposable use. The scanner unit is overall 10x10mm and electromagnetically actuated in 2-dimensions using a magnet that is attached to the 3D printed scanner and an external miniaturized coil. Using 3D printer's fabrication advantages the first two vibration modes of the scanner were tailored as out-of-plane displacement and torsion. The scanner employs lissajous scan, with 190 Hz and 340 Hz scan frequencies in the orthogonal directions and we were able to achieve +/- 5 degrees scan angles, respectively, with similar to 100 mA drive current. The lens which has 6-mm diameter and 10-mm focal length is 3D printed with Veroclear material and then polished in order to reach optical quality surface. Profilometer (Dektak) measurements indicate only x2 increase in rms roughness, with respect to a commercial glass lens having identical size and focal length.