Bio

Rossana Madrid is EE and Ph.D. in Bioengineering. She is currently Full Professor of Biomedical Transducers and Biosensors and Microsystems of the Biomedical Engineering Program, and also at the Doctoral degree, at the Faculty of Science and Technology at the University of Tucumán, Argentina. She is Independent Researcher at the National Council of Scientific and Technical Investigations of Argentina (CONICET). She has published R&D papers in national and international journals, two chapters in books and has developed two patents. She leads research grants and international cooperation grants with two German Universities. She leads graduate and postgraduate theses in the area of biosensors and microfluidics. Her main research fields include sensors and biosensors, microfluidic systems and paper-based POC (Point of care) devices for biomedical and environmental applications. Particularly, her microfluidic group is working now in the development, from one side, of a microfluidic paper POC device for the detection of Leishmaniasis in cooperation with the Experimental Pathology Institute of Salta, and on the other hand, of hybrid microfluidic chips. For the latter case, the incorporation of active elements (peristaltic pumps, valves, etc.) made with stimulus-sensitive hydrogels for fluid management, is evaluated. In the area of biosensors, her group won in February 2019, the Eukera prize to make the field validation of a biosensor for the early detection of HuangLongBing disease (HLB) in citrus plants.

Talk title: "Biosensors in Microfluidic Devices: Recent advances and future trends"

Abstract:

Biosensors are useful and interesting devices that made a wide range of biomedical, environmental or food determinations. These devices emerge in the sixties in the last century, and from that moment they had a great evolution both in the applications and in the technologies involved. Biosensors combine a molecular recognition element, the bioreceptor, with a signal conversion unit, the physical transducer. Over the last few years, biosensors were thought towards new fields of application. The recent advances in electrochemical biosensors, that incorporates nanotechnology, and their integration into compact analysis devices, may contribute to protect human and animal health, to facilitate environmental monitoring and ensure food safety. On the other hand, microfluidics, a very useful and promising technology, which emerged in the early 1990s arise for applications related to chemical separations, but now, it has been applied to a wide range of other applications, both for diagnostic and for synthesis. Moreover, when microfluidic is combined with biosensors, the possibilities seem to be limitless. The integration of biosensors with microfluidics provides miniaturized devices with very desirable properties, which combine the advantages of biosensors, such as low sample and reagents volumes, fast response and low-cost analysis; with microfluidics advantages such as laminar flow, minimal handling of hazardous materials, multiple sample detection in parallel, portability and versatility in design. The combination between electrochemical and microfluidic biosensors allows us to conceive three areas of intersection, which according to the Venn diagram proposed by Rackus et al., 2015, would be (A) electrochemistry and microfluidics, (B) electrochemical biosensors, (C) microfluidic biosensors, and (D) microfluidic electrochemical biosensors. There is a rich between electrochemistry, biosensors, and microfluidics, where the interesting topic is on how they are combining to form new application-areas. This includes not only new application, but also new materials such as paper-based chips for Point-Of-Care (POC) devices, new fabrication processes and new architectures. The progress in this area is so fast that, provided the scientific community focuses not only on the development of the bioanalytical systems but also on their validation, it will not take a long time to implement them in routine analysis.

Bio

Claudia Trejo is a bachelor in physical sciences from the Universidad de Concepción and master in Physical Science from the Instituto Balseiro. She obtained her Ph.D. in Physics at the Universitat de Barcelona in 2016 where she worked with the group of Dynamics of interfaces in nanotechnology, fluidics and biophysics. She has published R&D papers in international journals, colaborate in technological transfer projects with the Laboratory of Complex Fluids of the Centre de Recerca Matemàtica, and develops as a consultant for RheoDX inc.

Since 2018 she is developing her research at the Instituto de Física of the Pontificia Universidad Católica de Valparaíso where she is in charge of an international collaboration project with Barcelona and leads the Biorheology and Microfluidics Laboratory. Here with her group they develop experimental research in interface dynamics in microfluidics, hemorheology, red blood cells dynamics in confined geometries and mechanical properties of red blood cells. Currently, in collaboration with the Institute of Chemistry and the Medical Technology departament of PUCV, she is working on the development of Point of Care diagnostics techniques, relating the viscosity of blood with the mechanical properties of red blood cells.

Talk title: "Viscosity of blood and its relation with the mechanical properties of red blood cells"

Abstract:

The rheological properties of blood depend highly on the properties of its red blood cells, concentration, aggregation and membrane elasticity. These properties affect the viscosity of blood, as well as, its shear thinning behavior and, in some cases, are related to diseases, such as typical anemia or alpha-thalassemia, which affect the features of red blood cells. By mean of the experimental analysis of the front advancement of blood in a microchannel, we de- termine the viscosity of different samples of blood. We present a method that successfully scales the viscosity of blood of healthy, aged, anemic and alpha-thalassemic blood samples, according to the concentration, aggregation and the bending properties of its erythrocytes.

Bio

Sorin Melinte is Professor of Electrical Engineering in the Institute of Information and Communication Technologies, Electronics and Applied Mathematics at Université catholique de Louvain, Belgium. His current projects aim at developing novel nano- and micro-devices and hybrid inorganic-organic platforms for molecular electronics as well as scaffolds for bioelectronics and additive manufacturing via microfluidics. In particular, he uses high-resolution electron-beam nanolithography and soft-lithography to link bottom-up and top-down nano- and micro-structuring techniques for the engineering of smart materials.

Talk title: "Novel electro-optic techniques and nano-engineered transparent materials for microfluidics"

Abstract:

Designed with targeted properties and combining multiple attributes that allow them to be dynamic, ordered particle assemblies are strong candidates to replace the traditional structures processed with top-down fabrication approaches. Self-assembly by gravitational sedimentation is one of the methods largely used to organize particles in desired architectures. Understanding the physical phenomena that take place during self-assembly is a crucial step in controlling the structure and properties of the colloid-designed materials. In this respect, novel approaches to analyse the spatial and temporal information embedded in colloidal systems confined to microfluidic environments are needed.

Interestingly, coplanar waveguides can be used to study the physical phenomena that appear during gravitational sedimentation due to their unique response towards the dielectric properties of the surrounding environment. Microwave measurements using coplanar waveguides were reported for fluidic environments, with a focus on the dielectric characteristics of liquid samples. Various other electro-optic techniques and devices were designed at microwave frequencies to measure dielectric properties of biomaterials or analyte concentrations in microfluidic systems: coaxial probes, microstrip transmission lines or microwave resonators. We employ coplanar waveguides and simple microfluidic structures to study the on-chip sedimentation of polystyrene nano- and micro-spheres in aqueous solutions. Along with the detection of the solution's concentration, we monitor the time evolution of the underlying sedimentation processes and we devise a technique applicable to the specific detection of molecular species. We present a novel class of biosensing devices, based on coplanar waveguides fabricated onto thin glass and working in the frequency interval from 40 MHz to 40 GHz.

Finally, we discuss further integration of coplanar waveguides within lab-on-chip technologies. We address nano-engineered transparent electronics and the exploitation of complex circuitry for enhanced real-time monitoring of target analytes as well as for surveying soft matter self-assembly in various microfluidic environments.

Bio

Professor Jon Otto Fossum is a Full Faculty member at the Department of Physics in the Faculty of Natural Sciences at the Norwegian University of Science and Technology (NTNU) in Norway. He obtained his MSc and PhD in Physics in 1978 and 1983, respectively, at the Norwegian University of Science and Technology. At the beginning of his career, he had postdoctoral appointments at the University of Sherbrooke in Quebec, Canada; the Chemistry Department at the Massachusetts Institute of Technology (MIT)/USA, and in the Physics Department at the Risø National Laboratory in Denmark. During his career, he has supervised more than ten Post-doctoral and ten PhD students and more than 45 master’s degree students. In Norway he developed several courses, including “Soft Technologies”, “Cooperative particles: Patchy colloids, active matter and nanofluids” and “Soft Matter Physics”. Currently, he collaborates with more than 20 researchers across the world, including groups located in Norway, France, Sweden, the Netherlands, Germany, the United Kingdom, Portugal, Finland, Brazil and Cuba. In the last 10 years, he has also participated in more than 50 scientific meetings. And he has given lectures as an invited speaker at more than 80 international scientific meetings and he has authored more than one hundred publications.

Talk title: "Active versus driven particle assembly in microfluidic confinement"

Abstract:

Passive nano-/meso-/micro-colloids or passive micro-/milli-granules in suspension will in general be exposed to external force fields that make them move due to some specific mechanism that depends on the type of force field coupled to the colloid/particle material properties, on the carrier fluid properties, and on the spatiotemporal confinement of the system. The motion of such colloids/granules can be termed driven, or active.

Driven colloids/granules: Typically, when the external force fields (i.e. external to the suspended colloids/particles) are global, such as gravitational, electric, magnetic, hydrodynamic, or for instance linear global gradients in temperature or chemical concentrations in the carrier fluid (e.g. salinity gradients in water). Examples of phenomena that can be classified as exhibiting globally driven motion are for instance gravitational sedimentation of suspended micro-/milli-granules, or electrophoretic motion of suspended charged colloids/granules.

Active colloids/granules: Typically occurs when the external force fields are local on the colloidal/granular scale, in the sense that the individual suspended colloids/granules move as individual active swimmers due to individual exposure to a local directional field gradient that is attached to each individual. One example of this is a suspended patchy (including Janus) colloid/granula/drop that is propelled due to an attached (local) catalytic reaction chemical product gradient. Such active suspended colloids/granules are called swimmers because they move by dissipating their internally stored (attached) energy locally (i.e. they effectively have their “own motor”), with direction of motion which is independent of any global field, i.e. much like animals move (birds, fish, bacteria etc).

Collective behaviour (colloid/granule structural and dynamic assembly) is at least qualitatively different between these two fundamental ways of colloidal/granular suspension motion, i.e. one distinguishes between driven matter (e.g. collective phoretic or gravitational deposition of colloids/granules), and active matter (e.g. flocking or swarming behaviour).

System size, geometry and dimension (i.e. confinement) is of crucial importance for the behaviour of such driven/active colloid/granule assembly. This may for instance be coupled to the long-range nature of the hydrodynamic force field that is produced and “emitted” by any suspended colloid/granule that is moving translationally or rotationally.

Here we will exemplify all of the above by considering colloidal/granular driven/active assembly in suspension, limiting ourselves to two types of external fields: DC-electric partly aided by gravity, applied in two different microfluidic geometries: Droplet confined suspensions or quasi-2D (flattened confinement) suspensions.

We will give examples of driven colloidal shell assembly on drop interfaces by application of DC-electro-hydrodynamics and dielectrophoresis, using standard leaky dielectric oils as carrier fluids for non-polarisable and/or polarizable colloids. We will summarize how this can be used to fabricate static or dynamic colloidal shells with patchy structure and functionality.

Secondly, we will give examples of active granular bead assembly in suspension by exploiting the electrohydrodynamic Quincke-rotation effect (which typically is electric field induced purely rotational motion of a non-electrically-conducting particle suspended in a low-electrical-conductivity fluid (leaky-dielectric)). We study a system in quasi-2D microfluidic confinement with an applied DC-electric field perpendicular to the 2D-plane, where a monolayer of “Quincke rotors” are forced to “live” near a flat solid surface, and thus become a monolayer of self-propelled “Quincke rollers”. A Quincke roller’s direction of motion in the 2D plane is purely individual and normal to the electric field, with any direction possible, i.e. the electric field supplies energy (food), but not direction. Unlike animals, the “metabolism” of Quincke-rollers is instantaneous, and their “food” is translated into swimming immediately. We will show several types of assemblies that emerge from populations of granular Quincke-rollers confined in a 2D-microfluidic cell, such as crystallites, dynamic clusters, clusters of clusters, vortices, swirls, and polar liquids with uniform direction of motion.

Bio

Prof. Patrick Tabeling is leader of the group MMN (Microfluidics MEMS and Nanostructures), a prominent team in the field of microfluidics. He is the cofounder of the startup MicroFactory. He occupied various positions at the University: visiting researcher in Chicago University (1984-1985), Chargé/Directeur de Recherches CNRS in the Department of Physics in ENS (1985-2001), visiting professor to UCLA, Directeur de Recherches/Professor at ESPCI. He is cofounder of the Institut Pierre-Gilles de Gennes, and has been its director for the period July 2011-July 2018. He was professor chargé de cours at the Ecole Polytechnique (1996-2008). He is the author of 200 papers, 11 patents, 80 invited talks in international conferences; he was divisional editor of Physical Review Letters, Associate Editor to Physics of Fluids, PRF. He is member of Academia Europae. He published the book entitled “An introduction to microfluidics” (Oxford University Press – a French version being edited by Belin) in 2005.

Talk title: "Phoamtonics"

Abstract:

I will describe the work that we are performing in my group (MMN) at ESPCI, dedicated to the obtention of new materials using microfluidics. This work ranges from the assembly of droplets to create self assembled materials, to the realization of foams at the microscale, enabling the obtention of photonic band gap materials in the IR, and hopefully in the future, in the visible range. The word "phoamtonics", coined by S.Torquato, means: "Photonic band gaps of 3D foams"