Conference Agenda

TOM12 S01: Optofluidics: Morphological Optofluidics
Tuesday, 13/Sept/2022:
11:30am - 1:00pm

Session Chair: Paulo Marques, University of Porto & INESCTEC, Portugal
Location: B328

3rd floor, 32 seats

11:30am - 12:00pm
ID: 324 / TOM12 S01: 1
TOM 12 Optofluidics

Microdroplet lasers and their applications

Matjaž Humar1,2,3

1Condensed Matter Department, J. Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia; 2Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000, Ljubljana, Slovenia; 3CENN Nanocenter, Jamova 39, SI-1000 Ljubljana, Slovenia

Bio-integrated lasers, that are lasers made of biological and biocompatible materials and implanted into cells and tissues, are gaining interest from the research community. Here we show how whispering gallery mode microlasers and microcavities made of solid beads or droplets can be used for sensing different processes in biological materials including inside cells. By making microcavities of a predefined size they can also be used to encode some information and for cell tracking. Sensing and tracking can be applied to highly scattering tissues.

12:00pm - 12:15pm
ID: 151 / TOM12 S01: 2
TOM 12 Optofluidics

Imprinting characteristics of droplet lenses on liquid-repelling surfaces into light

Valeriia Bobkova1, Eileen Otte2,3, Sarah Trinschek4, Cornelia Denz1

1Institute of Applied Physics, University of Muenster, Germany; 2Geballe Laboratory for Advance Materials, Stanford University, USA; 3Center for Soft Nanoscience, University of Muenster, Germany; 4Department of Engineering Physics, Muenster University of Applied Sciences, Germany

We propose an experimental method that allows the investigation of droplets on liquid-repelling surfaces. The described technique goes beyond the standard imaging approaches and reveals a plethora of spatial droplet information, which is usually unavailable. Liquid droplet lenses shape the transmitted light field of a Gaussian laser beam passing though them, thereby forming refracted three-dimensional (3D) light landscapes. We investigate numerically and experimentally these 3D landscapes which are customized depending on the droplet shape as well as its refractive index and demonstrate the encoding of droplet information. This approach can also be applied for analyzing droplets showing high-speed dynamics, in order to reveal even minimal shape deviations. The developed technique can be used to complement the existing conventional tools for the investigation of the droplets formed on liquid-repelling surfaces.

12:15pm - 12:30pm
ID: 210 / TOM12 S01: 3
TOM 12 Optofluidics

Design of an all-liquid anamorphic imaging device

Daniel Sauter, Pengpeng Zhao, Hans Zappe

University of Freiburg, Germany

The design of a novel anamorphic optofluidic imaging system based on a pair of liquid lenses whose toroidal surfaces create different optical powers in the symmetry-axes is presented. Using electrowetting-on-dieletrics for actuation, a cylindrical fluidic system is actuated by 32 azimuthally-distributed electrodes allowing the definition of non-rotationally-symmetric surface shapes. We present the design and simulation of this optical system and show that an anamorphic ratio of 1.43 at a maximum field of view of 6.82° is attainable.

12:30pm - 12:45pm
ID: 332 / TOM12 S01: 4
TOM 12 Optofluidics

Analysis of size and concentration of microplastics in water using static light scattering combined with PCA and LDA

Mehrdad Lotfi Choobbari1, Leonardo Ciaccheri2, Tatevik Chalyan3, Barbara Adinolfi2, Wendy Meulebroeck3, Heidi Ottevaere3

1Vrije Universiteit Brussel, Department of Applied Physics and Photonics, Brussel Photonics, Pleinlaan 2, 1050 Brussels, Belgium; 2CNR-Istituto di Fisica Applicata "Nello Carrara", Via Madonna del Piano 10 - 50019, Sesto Fiorentino (FI) -Italy; 3Vrije Universiteit Brussel and Flanders Make, Department of Applied Physics and Photonics, Brussel Photonics, Pleinlaan 2, 1050 Brussels, Belgium

Quantitative analysis of size and concentration of microplastics is a crucial step for having a better understanding of plastic pollution in the environment. Such information is typically obtained in a single particle mode that significantly increases the analysis time and can be a cumbersome task. Therefore, we demonstrate here a measurement technique based on Static Light Scattering (SLS) combined with chemometric methods such as Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) for resolving the size and concentration of multiple microplastic particles in water. Two sets of samples with uniform and non-uniform size distribution of microplastics, called “monodisperse” and “polydisperse”, respectively, are fully investigated. It is shown that a relationship exists between the scattering signals of mono- and polydisperse samples on the PCA space. Hence, a PCA-LDA model that is constructed on the PCA space of monodisperse samples is used to discriminate the size of the microplastics in polydisperse samples. By specifying the size of the particles, their concentration is determined using a simple linear fit.

12:45pm - 1:00pm
ID: 296 / TOM12 S01: 5
TOM 12 Optofluidics

Deformation and shapping of optically trapped microdroplets: an ab-initio numerical study.

Hugo Chesneau1,2, Hamza Chraibi2, Jean-Pierre Delville2

1Commissariat à l’Energie Atomique et aux Energies Alternatives, Centre d’Etudes Scientifiques et Techniques d’Aquitaine, F-33116 Le Barp, France.; 2Université de Bordeaux, CNRS, LOMA, UMR 5798, F-33405 Talence, France

We numerically study the deformation of optically trapped microdroplets with optical tweezers using a house-made code based on the boundary elements method. Particular attention is paid to the droplets deformations itself and on the coupling between the electromagnetic waves forming the trap and the resulting droplets morphologies.