Dispensing of microlenses under adjustable gravity

Lenses are essential components in photonic systems to enable compact and high performance optical applications. While various lens fabrication methods exist, the influence of gravity on these processes has remained understudied due to limited access to variable gravity environments. This study leverages the Einstein-Elevator, the first third-generation drop tower in operation, to investigate the effects of gravity on the fabrication of polymer-based microlenses, which are produced by jet dispensing of sessile photopolymer droplets onto a glass substrate and subsequent UV curing. Systematic experiments were conducted under six different gravitational conditions (0 g, 0.17 g, 0.38 g, 0.6 g, 0.8 g, and 1 g) ∗ . The manufactured lenses were analyzed for morphological parameters including curvature, height, diameter, and contact angle. The findings reveal that while gravity has minimal effect on the morphology of small lenses, larger lenses show noticeable changes under reduced gravity. Through this study, it is possible to achieve tailored droplet morphologies by varying gravity. These results show that gravity influences manufacturing processes and that gravity is an essential parameter, which is not only relevant for future manufacturing processes in space.