Rotational UV lithography device for cylindrical substrate exposure

Optical photolithograhy is a well developed technique, which is normally restricted to planar substrates used in microelectronics or microelectromechanical system fabrication. For other applications—e.g., patterning of stents—photolithography would be an attractive alternative to techniques such as laser structuring provided that the planar technique could be adapted to cylindrical geometries. This study presents the development of a three-dimensional UV photolithography exposure method using a synchronizing movement between a planar Cr mask and a circular substrate. This technique was successfully applied to tubes with outer diameters between 1 and 5 mm. A lateral resolution for a $5μm$ feature size of $4.8μm$ was achieved, which is close to the resolution of $4.6μm$ for similar planar films.