The objective of this research is to develop the science base for tunable micro-lens arrays and explore their application for high throughput production. Tunable, millimeter-sized capillary lenses have recently been demonstrated by this group, with resolution approaching the maximum theoretical limit. The unique feature of these capillary lenses is that their tuning does not involve the movement of the contact line, where the fluids (the liquid that constitutes the lens and the gas surrounding it) meet the solid; contact line movement is avoided since it is a source of friction. The project will address two key issues: i) fast-response time and ii) small-scale packaging. The approach to meet the first challenge is to analyze shape changes in capillary lenses triggered via mechanical (pressure obtained by piezoelectric actuator) and electrical (electrokinetic) means. To address the second challenge, existing microfabrication techniques will be adapted and new ones developed for manufacturing capillary micro-lens arrays. For example, a novel technique may have to be developed to embed a porous medium in the middle of a glass chip for electrokinetic actuation. Micro-lens arrays will be studied at scales ranging from tens to hundreds of microns. The proposed research will ultimately make possible a technology to accurately control the minimum feature size by continuously adjusting the focal length of each micro-lens while the substrate is scanned underneath the array.
This project is expected to impact technological development, since capillary micro-lenses can be used to manipulate light, enabling high volume production (manufacturing) of small scale devices. Specifically, realization of an individually tunable micro-lens array can lead to dynamic photolithography, which can be used for example on curved surfaces. This is a gateway to 3-dimensional patterning capability with sub-micrometer features. Furthermore, the multidisciplinary senior team is expected to provide a unique research opportunity for educating graduate and undergraduate students.
