Tailored polymer microlenses on treated glass surfaces

Integrating arrayed biosensors (biochips) or micro- and nanofluidic devices with readout systems is an important step towards their realization in lab-on-a-chip devices. To this end, we present a straightforward method of fabricating polymer microlenses in precise locations, with desired optical characteristics, using a combination of two methods: surface energy tuning using low-energy electron irradiation, to control the numerical aperture, and time-controlled nanofountain pen deposition of polymer microlenses, to control the focal length. The authors demonstrate the tuning of focal length between 8 and 20 μ m with numerical apertures between 0.16 and 0.26.