Open postdoc position! Flow and deformation of microorganisms in biomicrofluidics

Postdoc on flow and deformation of microorganisms in biomicrofluidics

The flow physics of microorganisms is important to explain how they organize in their natural environment and in response to different stimuli, such as sunlight and chemical concentration gradients. For microorganisms that have been genetically modified to make products (foods, pharmaceuticals), the flow conditions in human-made flows, for instance in bioreactors, can be extreme compared to those in the natural environment. In these conditions, the forces applied by flowing fluids can be so large as to deform and break cells. While the deformation and rupture in flow of animal cells (cancer cells, red blood cells, etc) has been studied extensively for biomedical applications, the physics of deformation and rupture in flow of microoganisms remains largely unexplored, despite its potentially important implications in biotechnology and bioprocessing. The difference between the two types of cells is profound: while an animal cell is only enclosed by a soft, 2-nm thick lipid membrane, microorganisms also possess a structural layer up to 100s of nm thick, called cell wall, with a complex architecture and outstanding mechanical strength. The goal of this project is to address some fundamental questions from the perspective of soft matter and flow physics, to ultimately enable to control the deformation and microstructure of the cell wall of microorganisms in flow. You will address these questions using a combination of fluidic methods (microfluidics, acoustofluidics), imaging techniques (microscopy, fluorescent staining of cell components) and micromechanical measurements (AFM). You will join an inclusive and interdisciplinary team working on microscale transport phenomena in soft and biological matter. The Garbin lab is embedded in the Department of Chemical Engineering of TU Delft, and the project provides exciting opportunities for collaboration with colleagues in the Departments of Biotechnology and Bionanosciences, and with collaborators in Physical Chemistry and Soft Matter at Wageningen University. The postdoc position is initially for 1 year, with the possibility to extend for 1 additional year. The deadline for applications is 28/05/2021. For information on the opening, details of the application procedure, and to apply, see Job details (tudelft.nl).

New MSc project available! (TN/ChemE students)

Gas vesicles (GVs) are air-filled protein nanostructures that can be deployed to enable deep molecular ultrasound imaging in living organisms. To maximize the potential of this novel nanotechnology, a diversification of GV acoustic properties is needed. Your goal will be to develop new formulations based on gas vesicles for enhanced acoustic performance. The project is supervised by David Maresca (ImPhys) and co-supervised by Valeria Garbin (ChemE), and is suitable for a MSc student in Applied Physics (TN) or Chemical Engineering. This collaborative, interdisciplinary project is supported by the Delft Bioengineering Institute. Please contact David (D.Maresca@tudelft.nl) or Valeria (V.Garbin@tudelft.nl) to express your interest and find out more.

Available BSc/MSc projects in our group are listed here.

The Garbin Lab is moving

We are excited to announce that the lab is moving to TU Delft. Our research group joins the Transport Phenomena section of the Department of Chemical Engineering. We are already offering BSc/MSc projects for students of TU Delft, and soon we will advertise new openings for PhD students and postdocs.

The past 7 years in the Department of Chemical Engineering at Imperial College London have been very productive and successful, thanks to the creativity and perseverance of our PhD students and postdocs (Vincent Poulichet, Angelo Pommella, Marc Tinguely, Christiana Udoh, Akaki Jamburidze, Axel Huerre, Marco De Corato, Saikat Saha, Diego Baresch, Brice-Saint Michel, Nerine Joewondo) and to the support and friendship of colleagues, particularly Omar Matar, Serafim Kalliadasis, Ronny Pini, João Cabral, Paul Luckham, Roberto Rinaldi, Klaus Hellgardt, Geoff Maitland, Mengxing Tang, James Choi, John Seddon, and many others. Thank you!

Bubbly! From cracking joints to volcanoes

Photo by Heather Smith on Pexels.com

Happy 2019! If you found yourself marveling at the growing, rising, and bursting bubbles in your glass of champagne this New Year’s Eve, read on!

Bubbles are hidden inside a variety of man-made or natural materials and fluids. Lots of tiny bubbles give texture to chocolate mousse. A few tiny bubbles created when we crack our joints are the cause for the “crack” noise we hear. Huge bubbles are formed inside volcanoes because of the decompression of magma as it rises to the surface of the Earth. From sub-millimeter to kilometer scales, from industrial to biological processes, researchers strive to understand and control the presence and evolution of bubbles.

Together with Benjamin Dollet and Philippe Marmottant we have reviewed this fascinating topic in Bubble Dynamics in Soft and Biological Matter. The review paper will be published in volume 51 of the Annual Review of Fluid Mechanics on 07 January 2019, and is already available online.

Looking back on last year, here are some great review papers on bubbles that have appeared in 2018 (not an exhaustive list):

Here’s to another year of discoveries on bubbles leading to advances in fluid dynamics, electrochemistry, food engineering, geophysics and more!

Keith Haring at the colloidal scale and dynamic capillarity

Art and science have come together in our lab as we observed this pattern of microparticles sitting on the surface of a bubble. The observed microstructure resembles a human figure in American mural artist Keith Haring’s distinctive style.

The microstructures formed by colloids at fluid interfaces are usually due to electrostatics and capillarity. This unique microstructure was obtained by deforming a bubble decorated with colloidal particles with ultrasonic waves, resulting in complex dynamic interactions between the particles. The science behind making chains of particles by dynamic capillarity is explained in our paper Dynamic capillary assembly of colloids at interfaces with 10,000g accelerations, published today in Nature Communications.

The first author of the paper, Axel Huerre, led this work as a postdoc in our group in 2016-2018. He is now a postdoc at LadHyx, Ecole Polytechnique in Paris, where he studies the coupling between hydrodynamics and phase changes in capillary problems. The interaction model presented in the paper was developed by co-author Marco De Corato, also a postdoc in our group.

For the past 3 years we have been investigating extreme deformation of particle-laden fluid interfaces in the framework of ERC-funded project ExtreFlow. Marco has also developed a theoretical model for the effects of the dynamic deformation of the interface by oscillating particles, described in his paper Capillary interactions between dynamically forced particles adsorbed at a planar interface and on a bubble, which was published (Open Access) earlier this year in the Journal of Fluid Mechanics.

We will present both papers at the upcoming 12th European Fluid Mechanics Conference in Vienna (9-13 September 2018). If you’re interested, come along to our talks on Tuesday, 11 September, in the Mini Symposium “Particles at Interfaces”. See you then!

Image: 2-µm fluorescent microparticles at 30% surface coverage on an air bubble of radius 86 µm suspended in water. From: A. Huerre, M. De Corato, V. Garbin, Dynamic capillary assembly of colloids at interfaces with 10,000g accelerations, Nature Communications 9, 3620 (2018).