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Alfredo Lanzaro: Non-Linear Flows of Complex Fluids in Microfluidics: Elastic Turbulence, High Shear Viscometry of Biopharmaceuticals and Development of Novel Micro-Rheometers


Tid: 2017-03-22 14:15 till: 15:00
Plats: Kemicentrum, Lecture hall G

A Physical Chemistry Seminar by Dr. Alfredo Lanzaro, Physical Chemistry, Lund University.



Elastic turbulence is a new and still poorly understood flow regime. It occurs when low viscosity, weakly elastic fluids (e.g. semi-dilute polymer solutions) flow through micro-fabricated devices [1, 2]. The wide range of novel flow regimes achievable in microfluidics provides a useful benchmark to test microscopic constitutive models of complex fluids under highly deforming flow conditions. Also, a better understanding of non-linear effects in microfluidics is highly relevant to many industrial applications, including inkjet printing or spraying. By means of a combination of micro-velocimetry and pressure measurements, a platform was established for a quantitative characterisation and analysis of the highly non-linear dynamics achieved by polymer solutions in several complex flow geometries [3-5].   

Microfluidics can also provide the capability of measuring rheometric properties of complex fluids at large (104 s-1, or higher) and virtually inertia-less rates of deformation, and with minimum interfacial effects. This is especially relevant for bioprocessing industry, as future trends in treating various chronic diseases with recombinantly-produced therapeutic proteins (such as monoclonal antibodies) will require frequent and highly concentrated (100 g/L or higher)  doses of active protein ingredients in a small volume of liquid. The necessity of a technology for fast and high throughput formulation screening of concentrated protein solutions led us to the development of the “Rheo-chip” device [6]. It consists of micro-channels with various size and geometry, inherently replaceable pressure sensors, a high force syringe pump and a LabVIEW-based data acquisition platform. Using “Rheo-chip” and light scattering measurements, we have studied the effect of protein-protein interactions on the non-linear shear flow of concentrated antibody and globulin solutions. Also, a preliminary design of a novel microfluidic device suitable for linear and non-linear mechanical spectroscopy of complex fluids over a broad range of frequencies (1-100 Hz) will be presented.

It is envisaged that such quantitative approach to rheology of complex fluids in microfluidics will bring a step change to quantitative characterisation of macromolecular solutions of scientific and industrial interest, as well as constituting a robust test of the available theoretical and computational predictions.
[1]: Groisman, Alexander, and Victor Steinberg. Nature 405.6782 (2000): 53-55.
[2]: Groisman, Alexander, and Victor Steinberg. Nature 410.6831 (2001): 905-908.
[3]: Lanzaro, Alfredo, and Xue-Feng Yuan. Journal of Non-Newtonian Fluid Mechanics 166.17 (2011): 1064-1075.
[4]: Lanzaro, Alfredo, and Xue-Feng Yuan. Journal of Non-Newtonian Fluid Mechanics 207 (2014): 32-41.
[5]: Lanzaro, Alfredo, Zhuo Li, and Xue-Feng Yuan. Microfluidics and Nanofluidics 18.5-6 (2015): 819-828.
[6]: Xue-Feng Yuan. "Rheometry apparatus." U.S. Patent Application No. 13/813,933.