Ecole Polytechnique Federale de Lausanne

11 articles published in JoVE

• Bioengineering

  
  OnePot PURE Cell-Free System Laura Grasemann*¹, Barbora Lavickova*¹, M. Carolina Elizondo-Cantú¹, Sebastian J. Maerkl^{1 1}Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne We present a fast and cost-effective method to produce the recombinant PURE cell-free TX-TL system using standard laboratory equipment.

• Environment

  
  Flash Infrared Annealing for Perovskite Solar Cell Processing Pui Sha Victoria Ling^1,2, Anders Hagfeldt², Sandy Sanchez^{2 1}Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, ²Laboratory of Photomolecular Science (LSPM), École Polytechnique Fédérale de Lausanne (EPFL) We describe a flash infrared annealing method used for the synthesis of perovskite and mesoscopic-TiO2 films. Annealing parameters are varied and optimized for processing on fluorine-doped tin oxide (FTO) glass and indium tin oxide-coated polyethylene terephthalate (ITO PET), subsequently giving devices power conversion efficiencies >20%.

• Environment

  
  Combining Fluidic Devices with Microscopy and Flow Cytometry to Study Microbial Transport in Porous Media Across Spatial Scales David Scheidweiler^1,2, Pietro De Anna², Tom J. Battin¹, Hannes Peter^{1 1}Stream Biofilm and Ecosystem Research Laboratory, École Polytechnique Fédérale de Lausanne, ²Institute of Earth Sciences, University of Lausanne, CH-1015 Breakthrough curves (BTCs) are efficient tools to study the transport of bacteria in porous media. Here we introduce tools based on fluidic devices in combination with microscopy and flow cytometric counting to obtain BTCs.

• Engineering

  
  Monovalent Cation Doping of CH₃NH₃PbI₃ for Efficient Perovskite Solar Cells Mojtaba Abdi-Jalebi¹, M. Ibrahim Dar², Aditya Sadhanala¹, Satyaprasad P. Senanayak¹, Michael Grätzel², Richard H. Friend^{1 1}Cavendish Laboratory, University of Cambridge, ²Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne Here, we present a protocol to adjust the properties of solution-processed CH3NH3PbI3 through the incorporation of monovalent cation additives in order to achieve highly efficient perovskite solar cells.

• Bioengineering

  
  Harmonic Nanoparticles for Regenerative Research Flavio Ronzoni¹, Thibaud Magouroux², Remi Vernet¹, Jérôme Extermann³, Darragh Crotty⁴, Adriele Prina-Mello⁵, Daniel Ciepielewski⁶, Yuri Volkov⁴, Luigi Bonacina², Jean-Pierre Wolf², Marisa Jaconi^{1 1}Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, ²Physics Department, GAP-Biophotonics, University of Geneva, ³Laboratoire d'Optique Biomédicale (LOB), Faculté des Sciences et Techniques de l'Ingénieur, École Polytechnique Fédérale de Lausanne, ⁴Department of Clinical Medicine, School of Medicine, Trinity College Dublin, ⁵School of Medicine and CRANN, Trinity College Dublin, ⁶Nikon AG Instruments Protocol details are provided for in vitro labeling human embryonic stem cells with second harmonic generating nanoparticles. Methodologies for hESC investigation by multi-photon microscopy and their differentiation into cardiac clusters are also presented.

• Bioengineering

  
  Long-term Intravital Immunofluorescence Imaging of Tissue Matrix Components with Epifluorescence and Two-photon Microscopy Esra Güç*¹, Manuel Fankhauser*¹, Amanda W. Lund^1,2, Melody A. Swartz¹, Witold W. Kilarski^{1 1}Institute of Bioengineering and Swiss Institute of Experimental Cancer Research (ISREC), École Polytechnique Fédérale de Lausanne, ²Department of Cell and Developmental Biology and Knight Cancer Institute, Oregon Health & Science University The extracellular matrix undergoes substantial remodeling during wound healing, inflammation and tumorigenesis. We present a novel intravital immunofluorescence microscopy approach to visualize the dynamics of fibrillar as well as mesh-like matrix components with high spatial and temporal resolution using epifluorescence or two-photon microscopy.

• Engineering

  
  Nanomoulding of Functional Materials, a Versatile Complementary Pattern Replication Method to Nanoimprinting Corsin Battaglia^1,2, Karin Söderström¹, Jordi Escarré¹, Franz-Josef Haug¹, Matthieu Despeisse¹, Christophe Ballif^{1 1}Institute of Microengineering (IMT), Photovoltaics and Thin Film Electronics Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), ²Department of Electrical Engineering and Computer Sciences, University of California, Berkeley We describe a nanomoulding technique which allows low-cost nanoscale patterning of functional materials, materials stacks and full devices. Nanomoulding can be performed on any nanoimprinting setup and can be applied to a wide range of materials and deposition processes.

• Engineering

  
  Angle-resolved Photoemission Spectroscopy At Ultra-low Temperatures Sergey V. Borisenko¹, Volodymyr B. Zabolotnyy¹, Alexander A. Kordyuk^1,2, Danil V. Evtushinsky¹, Timur K. Kim^1,3, Emanuela Carleschi⁴, Bryan P. Doyle⁴, Rosalba Fittipaldi⁵, Mario Cuoco⁵, Antonio Vecchione⁵, Helmut Berger^{6 1}Institute for Solid State Research, IFW-Dresden, ²Institute of Metal Physics of National Academy of Sciences of Ukraine, ³Diamond Light Source LTD, ⁴Department of Physics, University of Johannesburg, ⁵CNR-SPIN, and Dipartimento di Fisica "E. R. Caianiello", Università di Salerno, ⁶Institute of Physics of Complex Matter, École Polytechnique Fédérale de Lausanne The overall goal of this method is to determine the low-energy electronic structure of solids at ultra-low temperatures using Angle-Resolved Photoemission Spectroscopy with synchrotron radiation.

• Immunology and Infection

  
  TransFLP — A Method to Genetically Modify Vibrio cholerae Based on Natural Transformation and FLP-recombination Melanie Blokesch^{1 1}Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL) A quick method to modify the genome of V. cholerae is described. These modifications include the deletion of single genes, gene clusters and genomic islands as well as the integration of short sequences (e.g. promoter elements or affinity-tag sequences). The method is based on the natural transformation and FLP-recombination.

• Medicine

  
  How to Measure Cortical Folding from MR Images: a Step-by-Step Tutorial to Compute Local Gyrification Index Marie Schaer¹, Meritxell Bach Cuadra^2,3, Nick Schmansky⁴, Bruce Fischl⁴, Jean-Philippe Thiran², Stephan Eliez^{1 1}Department of Psychiatry, University of Geneva School of Medicine, ²Signal Processing Laboratory, École Polytechnique Fédérale de Lausanne, ³Department of Radiology, University Hospital Center and University of Lausanne, ⁴Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital Measuring gyrification (cortical folding) at any age represents a window into early brain development. Hence, we previously developed an algorithm to measure local gyrification at thousands of points over the hemisphere¹. In this paper, we detail the computation of this local gyrification index.

• Neuroscience

  
  Focussed Ion Beam Milling and Scanning Electron Microscopy of Brain Tissue Graham Knott¹, Stéphanie Rosset¹, Marco Cantoni^{1 1}Centre of interdisciplinary electron microscopy, École Polytechnique Fédérale de Lausanne This protocol describes how resin embedded brain tissue can be prepared and imaged in the three dimensions in the focussed ion beam, scanning electron microscope.