Fabrication of Heterogeneous Microlenses using Self-Surface Tension

In this paper we propose novel fabrication processes of convex and concave microlenses on the same surface using inkjet-printing, hydrophilic confinement, self-surface tension, 3D-printer and replication process. We used LightTool (R) to simulate the freeform lens and transform the freeform surface into heterogeneous microlenses. The dimension of the microlens array is 2 mm x 2 mm x 1 mm which has concave and convex microlenses on the top surface. This microlens array which is composed by 1/4 cylinder and 1/8 sphere on the edge side. Because the edge side of the microlens is difficult to use the semiconductor manufacturing, we utilized the replication process combined with the semiconductor manufacturing to achieve this. First we used a glass as a substrate and the heterogeneous microlenses which made by the inkjet printer with the hydrophilic and hydrophobic of the SU-8 photoresist is on the top. Then we assembled with the module which was printed by 3D-printer. After this we can start the replication process. In the replication process we filled in with Polydimethylsiloxane (PDMS) and finally we can get the heterogeneous microlens array.