Fresnel phase plates as reconfigurable microfluidic lenses

Abstract

In this study, Fresnel phase plates were tested as reconfigurable lenses. The lenses were constructed from a Fresnel pattern which was transferred to a silicon substrate via photolithography. A layer of PDMS was spin-coated on the substrate and cured to produce the lens. This lens was attached to a PDMS control layer which enabled specific regions of the lens to addressed, via the application of pressure. It was concluded that based on the limitations of the pressure-based Fresnel lenses, liquid-filled flow channels, while possessing slower response times, might be a more promising means of modulating phase.