title: Reconfigurable and responsive droplet-based compound micro-lenses.
abstract: Micro-scale optical components play a crucial role in imaging and display technology, biosensing, beam shaping, optical switching, wavefront-analysis, and device miniaturization. Herein, we demonstrate liquid compound micro-lenses with dynamically tunable focal lengths. We employ bi-phase emulsion droplets fabricated from immiscible hydrocarbon and fluorocarbon liquids to form responsive micro-lenses that can be reconfigured to focus or scatter light, form real or virtual images, and display variable focal lengths. Experimental demonstrations of dynamic refractive control are complemented by theoretical analysis and wave-optical modelling. Additionally, we provide evidence of the micro-lenses' functionality for two potential applications-integral micro-scale imaging devices and light field display technology-thereby demonstrating both the fundamental characteristics and the promising opportunities for fluid-based dynamic refractive micro-scale compound lenses.
authors.affiliation: Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Nagelberg
authors.affiliation: Department of Chemistry and Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.|Department of Materials Science and Engineering and Department of Chemistry, The Pennsylvania State University, 427 Steidle Building, University Park, Pennsylvania 16802, USA.
authors.forename: Lauren D
authors.identifier: 0000-0002-3287-3602
authors.initials: LD
authors.lastname: Zarzar
authors.affiliation: Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Natalie
authors.initials: N
authors.lastname: Nicolas
authors.affiliation: Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany.
authors.forename: Kaushikaram
authors.identifier: 0000-0002-9050-5672
authors.initials: K
authors.lastname: Subramanian
authors.affiliation: Department of Chemistry and Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.|Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
authors.forename: Julia A
authors.identifier: 0000-0001-9215-520X
authors.initials: JA
authors.lastname: Kalow
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Vishnu
authors.identifier: 0000-0002-5764-9383
authors.initials: V
authors.lastname: Sresht
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Blankschtein
authors.affiliation: Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: George
authors.initials: G
authors.lastname: Barbastathis
authors.affiliation: Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany.
authors.forename: Moritz
authors.initials: M
authors.lastname: Kreysing
authors.affiliation: Department of Chemistry and Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Swager
authors.affiliation: Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Mathias
authors.identifier: 0000-0001-7395-8824
authors.initials: M
authors.lastname: Kolle