Precision assembly of nanoparticles, top-down meets bottom-up Thursday, 10 November 2016 EPFL researchers have developed a method to place and position hundreds of thousands of nanoparticles very precisely on a one centimeter square surface. This will open new doors in nanotechnologies. Whether it has to do with making pens or building space shuttles, the manufacturing process consists of creating components and then carefully assembling them. But when it comes to infinitely small structures, manipulating and assembling high-performance nanoparticles on a substrate is no mean feat. Researchers in EPFL’s Laboratory of... Read More...
Thousand of nanoantennas to enlighten living cells Friday, 22 May 2015 Large-scale arrays of photonic antennas for nanoscales dynamics in living cell membranes. A recent study carried out in collaboration with researchers of the EPFL and Thomas van Zanten, Mathieu Mivelle, and Carlo Manzo in the Single Molecule Biophotonics group led by ICREA Professor at ICFO Maria Garcia-Parajo, has succeeded in fabricating hundreds of thousands of photonic antennas to measure for the first time the nanoscale dynamics of individual molecules in living cells. This work constitutes a major breakthrough in our ability to... Read More...
Tracing the near field line Monday, 26 January 2015 Single Molecule Dipole Maps the Local Vector Field of an Optical Nano-antenna In a recent study, Anshuman Singh and Gaëtan Calbris of the Molecular NanoPhotonics group led by ICREA Professor at ICFO Niek van Hulst have used single molecule “point” dipoles and a scanning optical antenna to map the 3D vectorial antenna field with 1 nm resolution and to achieve enhanced fluorescence imaging with 40 nm FWHM response. The work, supported by EU project NanoVista, was published in NanoLetters. Read More...
Antenna-in-box platform to enhance single molecule detection Monday, 26 January 2015 Researchers from ICFO and CNRS publish results in Nature Nanotechnology. One of the ultimate goals of molecular biology is to watch how single molecules work at physiological conditions. This involves high local concentrations in the micromolar range, and calls for more than three orders of magnitude shrinking of the detection volume as compared to conventional optical microscopes. Hence, new nanotechnology tools need to be introduced in order to reach ultra-small detection volumes and turn single molecules into bright light sources. Read More...
The balance between adhesion and migration Monday, 26 January 2015 Re-activating adhesion on cells of the immune system in Plos One A recent single molecule study carried out by Kyra Borgman, Thomas van Zanten and Carlo Manzo in the Single Molecule Biophotonics group led by ICREA Professor at ICFO Maria Garcia-Parajo sheds new light on the tight balance between cell adhesion and migration in the immune system. The study reveals that integrin receptors (involved in controlling cell adhesion and migration) can be re-activated in mature dendritic cells and that their lateral mobility on the plasma... Read More...
EPFL researchers have developed a method to place and position hundreds of thousands of nanoparticles very precisely on a one centimeter square surface. This will open new doors in nanotechnologies.
Whether it has to do with making pens or building space shuttles, the manufacturing process consists of creating components and then carefully assembling them. But when it comes to infinitely small structures, manipulating and assembling high-performance nanoparticles on a substrate is no mean feat.
Researchers in EPFL’s Laboratory of Microsystems, which is headed by Jürgen Brugger, have come up with a way to position hundreds of thousands of nanoparticles very precisely on a one centimeter square surface. The nanoparticles were placed within one nanometer – versus 10 to 20 nanometers using conventional methods – and oriented within one degree.
Their work, which was published in Nature Nanotechnology, sets the stage for the development of nanometric devices such as optical detection equipment and biological sensors. “If we manage to place gold nanoparticles one nanometer apart, we could, for example, confine light to an extraordinary degree and detect or interact with individual molecules,” said Valentin Flauraud, the lead author.
“Playing golf” with nanoparticles
For their study, the researchers used gold nanoparticles that were grown chemically in a liquid. “These nanoparticles exhibit better properties than those produced through evaporation or etching, but it is more difficult to manipulate them, because they are suspended in a liquid,” said Flauraud.
Their technique consists of taking a drop of liquid full of nanoparticles and heating it so that the nanoparticles cluster in a given spot. This drop is then dragged across to a substrate with nanometric barriers and holes.
When the nanoparticles encounter these obstacles, they detach from the liquid and are captured by the holes. “It’s a little like playing miniature golf,” said the researcher. Each trap is designed to orient a nanoparticle in a specific way. “The challenge was to figure out how the liquid, the particles and the substrate interact at the nanometric scale so we could trap the nanoparticles effectively,” said Massimo Mastrangeli, the second author and now a researcher at the Max Planck Institute for Intelligent Systems in Stuttgart.
Writing out the alphabet with nanoparticles
To show how well their method works, the researchers took on several challenges. First, they tested the optical properties of their system with a powerful transmission electron microscope in EPFL's Interdisciplinary Center for Electron Microscopy (CIME).
They then showed that their technique could be used to produce geometrically complex structures by writing out the alphabet with nanoparticles – the smallest segment display in the world. “All of this work was conducted at EPFL and is the result of strong synergies between the various technical platforms and the labs,” said Professor Brugger. “It’s an excellent example of how top-down and bottom-up methods can be combined, opening the door to numerous unexplored fields of nanotechnology.”
Nanophotonics and Metrology Laboratory (NAM)
Center of MicroNanoTechnology (CMi)
Interdisciplinary Center for Electron Microscopy (CIME)