Conference Agenda

TOM12 S02: Optofluidics: Emerging Concepts
Tuesday, 13/Sept/2022:
2:30pm - 4:00pm

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

3rd floor, 32 seats

2:30pm - 3:00pm
ID: 159 / TOM12 S02: 1
TOM 12 Optofluidics

Heliconical Cholesterics: new opportunities for optofluidics?

Francesco Simoni

ISASI - CNR - Italy, Italy

In this presentation the novelty represented by the heliconical cholesteric liquid crystals (Ch-OH) for easy electric and optical control of optical properties are highlighted. After a quick summary of their electro-optical properties, an account of the recent experimental and theoretical achievements about the nonlinear optical response of Ch-OH will be given. The peculiar conical structure allows an easy control of the spectral location of the Bragg resonance making possible effects never observed previously in pure liquid crystals, making these materials attractive for development of several optical devices.

3:00pm - 3:15pm
ID: 333 / TOM12 S02: 2
TOM 12 Optofluidics

Trapping, characterization and reactions of biocolloids in a salinity gradient

Martin Kjærulf Rasmussen, Jonas Nyvold Pedersen, Rodolphe Marie

Technical University of Denmark, Denmark

The properties of soft matter nanoparticles like exosomes are interesting for drug delivery and diagnostics applications. However, the simultaneous characterization of multiple properties, e.g., size and zeta potential, can only be done serially and is highly sensitive to the purification prior to characterization. Here we show how a salt gradient established in a nanofluidic channel induces opposing transport of particles and liquid that trap the particles. Particles are thus accumulated in the trap. We show how optical microscopy images of the particle positions in the salinity gradient provide a measurement of the size and surface charge. We demonstrate the method on a sample of exosomes and on individual particles. Finally, we show how biomolecular reactions at the surface of the nanoparticle can be detected from the optical microscopy analysis of the particles’ trapping position

3:15pm - 3:30pm
ID: 326 / TOM12 S02: 3
TOM 12 Optofluidics

Size-based chromosome separation in a microfluidic particle separation device using viscoelastic fluids

Therese Rahbek Wassberg1, Mathilde Lassen Witt1, Murat Serhatlioglu1, Christian Friberg Nielsen2, Ian David Hickson2, Anders Kristensen1

1Technical University of Denmark (DTU), Denmark; 2University of Copenhagen (KU), Denmark

Viscoelastic flow-based particle manipulation techniques enable bio-particle focusing, separation, and enrichment by precisely tuning the rheological parameters, flow conditions, and microchannel geometry. In this study, we fabricated a PDMS-based single inlet/outlet microchannel to separate bio-particles by their size ranging from 1-10 µm. Flow conditions and rheological properties are optimized using 2 µm and 4 µm Polystyrene beads to reach the best particle separation condition. We demonstrated the size-based separation of human chromosomes by separating 1-2 µm size small chromosomes from 8-10 µm size large chromosomes. Thanks to its miniaturized size and simplicity, the isolation chip and unique viscoelastic separation method have great potential to be used as a future pioneering tool for genetic applications to study chromosome abnormalities such as fragile-X and trisomy.