Smartphone-Based Microscopy with Silicone Lens Embedding Nanostructured Photonic Components

Abstract

In this work [1], the moldless preparation of a silicone (i.e., poly(dimethylsiloxane), PDMS) lens embedding nanostructured porous silicon (PSi) optical components is discussed, along with its application to smartphone-based microscopy in biology and medicine.A nanostructured PSi surface is used to redirect a droplet of uncured silicone into a lightweight, high-magnifying lens (10 mg mass and 4.7 mm focal length). Geometrical and optical properties of the lens are easily controllable by tuning of the nanostructure features (i.e., thickness and porosity of PSi). Design of the PSi layer as an optical component (e.g., distributed Bragg reflector, rugate filter, resonant cavity) further enables to embed nanostructured optical elements in the lens, so as to select the light transmitted through the lens itself. The fabrication process of the lens has high reliability (yield >95%), low-cost (0.01 $).As proof of concept applications, using a single monolithic lens/filter element self-adhered to a commercial smartphone camera we will discuss: fluorescence imaging and counting of live/dead isolated human cancer cells with high magnification and rejection of the excitation light; selection of a narrow wavelength band from the emission spectrum of a fluorescent dye; changing of the color of a white light emitting diode (from red to blue) through shaping of the diode emission spectrum.[1] Mariani, V. Robbiano, R. Iglio, A. A. La Mattina, P. Nadimi, J. Wang, B. Kim, T. Kumeria, M. J Sailor, G. Barillaro, Moldless Printing of Silicone Lenses with Embedded Nanostructured Optical Filters, Adv. Funct. Mater., 1906836 (2019).