Electrodispensing of Microspheroids for Lateral Refractive and Reflective Photonic Elements

An electrodispensing fabrication process is introduced in this work for the fabrication of microspheroid photonic elements. The fabrication process is suitable for in situ patterning of microdroplet spheroids whose optical responses can be tailored for use in on-chip focusing or retroreflecting. Theoretical ray-based and wave-based analyses are used to characterize the optical responses of these microspheroid systems. Design-based details are extracted from these theoretical conclusions, and the electrodispensing fabrication process needed to pattern the structures is presented. Polymer microspheroids with diameters down to 150 μm and contact angles up to 160° are fabricated, and the focusing/retroreflecting characteristics of these structures are experimentally characterized.