Creation of convex microlenses in PDMS with focused MeV ion beam

In this work the creation of convex microlenses is presented in polydimethylsiloxane using shrinkage of the polymer due to energetic ions. The creation process is based on the observation that the PDMS shrinks due to irradiation and the surface of the unirradiated areas will have a regular curvature between the irradiated places. The created microlenses were arranged in arrays, the diameters were varied between 15 and 200 μm. The properties of the lenses were investigated using an AFM and a profilometer. The profile of the lenses turned out to be parabolic, the focal lengths were found to be between 18 and 180 μm, that can be adjusted with the delivered ion fluence and the lens diameter.