Refractive microlens arrays (MLAs) are widely used in many electro-optical devices due to their high performance and low optical loss. To fabricate a microlens array effectively, we have proposed a novel fabrication method based on a selective-area patterning method. The surface properties of glass substrates were defined as either hydrophilic or hydrophobic regions by microcontact printing of self-assembled monolayers (SAMs). Consequently, the microlens arrays were self-organized on the hydrophilic regions after the lens materials were nozzle-spread followed by UV curing. As a result, we have demonstrated microlenses with 50, 75, and 100 μm footprints, and f numbers as low as 5.4. The focused spot size of the 50 μm lens was 9.82 μm, which is near the diffraction limit. The optical measurement shows excellent light collecting efficiency of a microlens array, which is suitable for many electro-optical applications. Furthermore, all fabrication steps can be accomplished in ambient environment and at room temperature. It is anticipated that the present proposed method has great potential for mass production.
- Microcontact printing
- Microlens array
- Selective-area patterning method