Events The 7th International Multidisciplinary Conference on Optofluidics 2017

Event submissions

Published

10.3390/optofluidics2017-04529

This submission belongs to the session 16. Lab on a chip of the event The 7th International Multidisciplinary Conference on Optofluidics 2017

Published date

21 Jul, 2017

Citation

Paolo Minzioni, Giovanni Nava, Tie Yang, Valerio Vitali, Francesca Bragheri, Roberto Osellame, Tommaso Bellini, Optofluidic Microrheometer: study of viscosity behavior in transient networks, in Proceedings of The 7th International Multidisciplinary Conference on Optofluidics 2017, Singapore, 25 July–28 July 2017, MDPI: Basel, Switzerland, doi: 10.3390/optofluidics2017-04529

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Optofluidic Microrheometer: study of viscosity behavior in transient networks

Giovanni Nava ¹

Tie Yang ²

Valerio Vitali ²

Francesca Bragheri ³

Roberto Osellame ³

Tommaso Bellini ¹

Paolo Minzioni ²

1. Dept. of Medical Biotechnology and Translational Medicine, Universita degli Studi di Milano, via Fratelli Cervi 93, I-20090 Segrate, MI, Italy.

2. Dept. of Electrical, Computer, and Biomedical Engineering; Università di Pavia Via Ferrata, 5 A I-27100 Pavia ITALY

3. Istituto di Fotonica e Nanotecnologie (IFN-CNR) & Dipartimento di Fisica, Politecnico di Milano,Piazza Leonardo da Vinci 32, 20133 Milano, Italy

Abstract

It is well known that analyzing the dynamic behavior of reversible gels is a tough job, as it requires a detailed control of geometry, bond lifetimes, etc… . In this context, we use an optofluidic microrehometer to investigate the properties of a system composed by DNA nanostars.

The device, allowing to test samples with volume smaller than 1 uL, consists in a square section microchannel realized in a glass substrate and having a couple of facing waveguides, realized by fs-laser inscription technique, on the two sides of the channel. Using the optical-shooting technique (T. Yang, et al. Scientific Reports 6, 23946 2016; T. Yang et al. Micromachines 8, 65, 2017.), we investigated the system viscosity as a function of the temperature and of the applied optical force, observing the transition from Newtonian to shear-thinning behavior while lowering the temperature below the gelation threshold.

Stress-strain curves analysis allowed assessing the system activation energy, which is in good agreement with that obtained by dynamic light scattering measurements.

Keywords

optical forces

hydrogel

DNA

rheometry

Nanofluidics for Single-Cell Proteomics with Single-Molecule Sensitivity

Optofluidics biosensor based on speckle focusing