Colloquium Jerome Bibette (Tuesday December 6, 16:00h, WA4)We herewith invite you for a MESA+ Nanofluidics colloquium that will be given by
Professor Jerome Bibette
Laboratoire Colloides et Matériaux divisés, ESPCI Paris Tech
The title of his presentation is
Microorganism Growth Variability in Droplets
When: Tuesday December 6, 16.00 h
Where: Prof.dr. G. Berkhoff zaal (Waaier 4)

Colloquium Bob Evans (Thursday November 10, 14.00 h, ZH 286)We herewith invite you for a colloquium given by Professor Bob Evans from the University of Bristol.
The title of his presentation is:
"Phase behaviour and Structure of Confined Fluids: A Novel Delocalized Interface Phase"
When: Thursday November 10, 14.00 h
Where: ZH 286

Nanofluidics Colloquium Tuesday 18 octoberSilica nanochannels filled with electrolytes are fundamental components in contemporary bionanofluidics, but despite the apparent simplicity of such systems, it is a challenge to develop a theoretical description of them with predictive power. In the talk is presented a combined theoretical and experimental analysis of the solid-liquid interface of fused silica nanochannels with and without a hydrophilic cyanosilane coating [1,2,3]. Our theoretical model consists of three parts: (i) a chemical equilibrium model of the bare or coated wall, (ii) a chemical equilibrium model of the buffered bulk electrolyte, and (iii) a self-consistent Gouy–Chapman–Stern triple-layer model of the electrochemical double layer coupling these two equilibrium models. To

PhD Defence of Dileep MampallilDileep Mampallil Augustine defended his PhD thesis “Microfluidic flow driven by electric fields” on Thursday, 22nd of September, 2011 at 12:45h in the Waaier. After listening to the defence, the graduation committee consisting of Prof.dr. G van der Steenhoven, Prof.dr. R.G.H. Lammertink, Prof.dr. J.G.E. Gardeniers, Dr.ir H.L. Offerhaus, Dr.ir C.G.P.H. Schroen, Prof.dr.ir. J.M.J. den Toonder as well as assistant promoter Dr. H.T.M. van den Ende and promoter Prof.dr. F. Mugele awarded the degree to – now – Dr. Mampallil.

PhD Defence Sissi de BeerSissi de Beer defended her PhD thesis „Probing the properties of confined liquids” on Friday, May 27 at 16:45h in the Waaier. After listening to the defense, the committee consisting of Prof. W.J. Briels, Prof. V. Subramaniam, Prof. G.J. Vasco, Prof. E. Charlaix, Prof. J.W.M. Frenken as well as assistant promoter Dr. H.T.M. van den Ende, promoter Prof. Frieder Mugele and referee Dr. W.K. den Otter awarded the degree to – now – Dr. de Beer.

Drops on functional fibers: from barrels to clamshells and backVariation of the contact angle of drops on fibers with a previously unachieved precision and reversibility has allowed PCF members and Ciro Semprebon and Martin Brinkmann of the Max Planck Institute in Goettingen to determine the stability limits of two competing drop morphologies...

IOP-selectThe editors of Journal of Physics: Condensed Matter chose the recent article S. de Beer, D. van den Ende and F.Mugele, J PhysCondens Matter 23 112206 (2011) {link} to be an IOPselect publication. Moreover the paper was featured in the IOP LabTalk {link}.

PhD Defence of Hao GuHa o Gu defended his PhD thesis „Controlling two phase-flow in Microfluidic systems using electrowetting” on Friday, March 18 at 12:30h in the Waaier. After listening to the defense, the committee consisting of Profs. G van der Steenhovenl, R.M. Boom, A. van den Berg, J.G.E. Gardeniers and R.G.H. Lammertink as well as assistant promoter Dr. Michel Duits and promoter Prof. Frieder Mugele awarded the degree to – now – Dr. Gu.

PhD Defence of Burak EralBurak Eral defended his PhD thesis „Colloidal Suspensions Under External Control” on Friday, March 04 at 12:30h in the Waaier. After listening to the defense, the committee consisting of Profs. Willem Kegel, Jurriaan Huskens, Leon Lefferts, Stefan Luding, and Wim Briels as well as assistant promoter Michel Duits and promoter Prof. Frieder Mugele awarded the degree to – now – Dr. Eral.

Droplet on demandWe present a novel method that implements voltage programmable on-demand droplet formation and on-demand droplet merging. This method offers a way of miniaturized automated microfluidic chip for screening in various areas of chemistry and biochemistry.

AIP BiomicrofluidicsProf. Frieder Mugele has been appointed as a member of the Editorial Board of the journal Biomicrofluidics. Biomicrofluidics is an online open-access journal published by the American Institute of

VICI grant for Frieder MugeleFrieder Mugele received a VICI grant from NWO/STW. Together with his team he will develop “Electrically Switchable Superhydrophobic Surfaces” in the upcoming five years.

Cell Spread: electrowetting for cancer researchThe PCF group starts up a new collaboration with the MCBP group of Leon Terstappen to improve the early detection and to study the properties of circulating tumor cells.

PCF contributes to new FOM program on NanotribologyA new collaborative FOM program on Fundamental Aspects of Friction has recently been approved by FOM. A consortium of eight research groups will address the question on how to bridge the gap from idealized individual dry nanoscale tribological contacts to the true practical situation of multiple asperity contacts with elastic and plastic behavior in the presence of lubricants. The PCF group will contribute to this program with a study on Nanolubrication.

Droplet impact on superhydrophobic substratesUsing electrowetting to control the bouncing/ sticky droplet transition on superhydrophobic substrates

Slow diffusion in spatial confinementWhen a colloidal particle approaches a wall, its hydrodynamic interaction with the wall causes the particle to slow down. This effect was studied in the PCF group and is now published.

Bubble bursting in NatureOn June 10, the article “Daughter bubble cascades produced by folding of ruptured thin films” appeared in Nature. A PhD student within the PCF group, Riëlle de Ruiter, contributed to this research during her MSc internship in the group of Howard Stone at Harvard University.

Gekko adhesie bestudeerdSissi de Beer, Aram Klaassen en Bart Stel hebben het adhesiemechanisme van een gekko bestudeerd en dit werk zal in het juli nummer van het Nederlands Tijdschrift voor de Natuurkunde worden gepubliceerd.

NWO Project granted: Suspensions in confined flowNWO-CW, the chemistry section of the Dutch Science Foundation, granted 28 out of 129 proposals this year within its ECHO program. One of the successful ones was the proposal entitled “Influence of wall roughness and particle adhesion on confined flows”.

Lorentz Center Workshop: Adsorption of Ions at Solid-Electrolyte InterfacesSolid-electrolyte interfaces are ubiquitous in nature, from the aqueous solution surrounding living cells to brine in oil wells and rock in the ocean. They also play a decisive role in environmental science (in processes leading to ozone depletion, for example) or in technology (water purification and desalination, efficiency of energy storage and harvesting devices). There are a few examples of phenomena finely controlled by the particular arrangement of adsorbed ions at or near the surface of an immersed solid.

Ivan Stojanovic and Arjen Pit win Simon Stevin Leerling poster awardThe poster made by Ivan Stojanovic and Arjen Pit showed their STW funded research and was rewarded with the Simon Stevin Leerling-prize. Ivan works on specific detection of molecules excreted by cancer cells, while Arjen works on cell-containing drop manipulation in microchips. The combination of these two techniques promises a quick diagnosis of a patient’s type of cancer. This personalized approach allows to use cancer drugs targeted to this specific type of cancer, which in turn results in less drug-induced negative side-effects for the patient.
After Ivan’s eloquent two minute presentation of the poster a large majority of the audience (58%) voted for this project. Arjen and Ivan happily take home 1000 euros.

PHD DEFENCE OF DIETER 't MANNETJECongratulations, Dieter!
Dieter ‘t Mannetje defended his PhD thesis „Drops, contact lines, and Electrowetting” on Friday, September 5th in the Waaier. After listening to the defense, the committee consisting of Prof. H.J.W. Zandvliet, Prof. A.A. Darhuber, Prof. J. Westerweel, Prof. M.T. Kreutzer, Dr. J.H. Snoeijer and Dr. R. Badie as well as assistant promoter Dr. H.T.M. van den Ende, and promoter Prof. F. Mugele and presided by Prof. G. van der Steenhoven awarded the degree to – now – Dr. ‘t Mannetje.

FP7 GRANT ON SEMI-SOLID FLOW BATTERIESFrom September 2013, the PCF group participates in the FP7 project: “Interfaces of Fluid Electrodes: New Conceptual Explorations” (INFLUENCE). The aim of this project is to explore new types of fluids for semi-solid flow batteries. In SSFBs, electrochemically active (e.g. Li containing) particles are suspended in a non-aqueous medium together with auxiliary nanoparticles that form a conducting network. The contribution of the project in Twente (led by Michel Duits) to the European consortium will be to analyze and optimize the rheological and conductive behaviors of the fluids inside microchannels. In particular the interface between the slurries and the current collector is expected to play an important role.

AFM force spectroscopy in liquidThe article "Atomic force microscopy of confined liquids using the thermal bending fluctuations of the cantilever " by Fei Liu et al is accepted by Physical Review E. The paper describes how to reconstruct distance-dependent conservative and dissipative forces at the liquid-solid interface by using the thermal fluctuations of a cantilever. The approach avoids difficulties in force inversion related to the active drive of the cantilever. The referees found it an important contribution to the AFM force spectroscopy community.

JM Burgers Center course on Capillarity-driven flows in microfluidicsNext week 15-19 April.

Professor Cohen Stuart new part-time chair holder of the Physics of Complex Fluids groupProf. Martien Cohen Stuart is appointed as part-time professor Interfacial Physical Chemistry within the Physics of complex fluids (PCF) group at the University of Twente. Prof. Martien Cohen Stuart has received numerous awards, including the ERC advanced grant. He plays an important role within the Association of the Dutch Chemical Industry and he is chair of the Dutch Polymer Institute(DPI).

Prof. Cohen Stuart will contribute in research within PCF and the MESA+ institute for Nanotechnology to the fundamental understanding of the interaction of solid surfaces with electrolytes and complex fluids, which play – amongst others– a central role in enhanced oil recovery.

His research comprises the broad field of “soft matter”, with a special interest for (bio)polymers and surfaces. The PCF group expects a direct contribution to fundamental research of physical mechanisms that may ultimately also break grounds for new technological applications in the future. The PCF group also likes to join more national organized activities within the Dutch Chemical Industry association and the Dutch Polymer Institute

Michel Duits associate professorAs per january 2013, Michel Duits has been granted associate professorship by the faculty of Science and Technology. The PCF chair congratulates him, and wishes him success with the further development of his research and teaching. In the coming years Michel will extend his physico-chemical research line on colloids, interfaces and microfluidics. Interactions between particles and interfaces will play a prominent role in this work. In the new educational program he will become coordinator and teacher in the Dynamics module in the first year of Applied Physics.