Nav: Home

A 'nano-golf course' to assemble precisely nanoparticules

October 03, 2016

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 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."
-end-
Source: Nanoscale topographical control of capillary assembly of nanoparticles

Partners: Nanophotonics and Metrology Laboratory (NAM)
Center of MicroNanoTechnology (CMi)
Interdisciplinary Center for Electron Microscopy (CIME)

Ecole Polytechnique Fédérale de Lausanne

Related Nanoparticles Articles:

Study models new method to accelerate nanoparticles
In a new study, researchers at the University of Illinois and the Missouri University of Science and Technology modeled a method to manipulate nanoparticles as an alternative mode of propulsion for tiny spacecraft that require very small levels of thrust.
Actively swimming gold nanoparticles
Bacteria can actively move towards a nutrient source -- a phenomenon known as chemotaxis -- and they can move collectively in a process known as swarming.
Nanoparticles take a fantastic, magnetic voyage
MIT engineers have designed tiny robots that can help drug-delivery nanoparticles push their way out of the bloodstream and into a tumor or another disease site.
Quantum optical cooling of nanoparticles
One important requirement to see quantum effects is to remove all thermal energy from the particle motion, i.e. to cool it as close as possible to absolute zero temperature.
Nanoparticles help realize 'spintronic' devices
For the first time researchers have demonstrated a new way to perform functions essential to future computation three orders of magnitude faster than current commercial devices.
Directed evolution builds nanoparticles
Directed evolution is a powerful technique for engineering proteins. EPFL scientists now show that it can also be used to engineer synthetic nanoparticles as optical biosensors, which are used widely in biology, drug development, and even medical diagnostics such as real-time monitoring of glucose.
What happens to magnetic nanoparticles once in cells?
Although magnetic nanoparticles are being used more and more in cell imaging and tissue bioengineering, what happens to them within stem cells in the long term remained undocumented.
Watching nanoparticles
Stanford researchers retooled an electron microscope to work with visible light and gas flow, making it possible to watch a photochemical reaction as it swept across a nanoparticle the size of a single cold virus.
Nanoparticles to treat snakebites
Venomous snakebites affect 2.5 million people, and annually cause more than 100,000 deaths and leave 400,000 individuals with permanent physical and psychological trauma each year.
Nanoparticles in our environment may have more harmful effects than we think
Researchers warn that a combination of nanoparticles and contaminants may form a cocktail that is harmful to our cells.
More Nanoparticles News and Nanoparticles Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#540 Specialize? Or Generalize?
Ever been called a "jack of all trades, master of none"? The world loves to elevate specialists, people who drill deep into a single topic. Those people are great. But there's a place for generalists too, argues David Epstein. Jacks of all trades are often more successful than specialists. And he's got science to back it up. We talk with Epstein about his latest book, "Range: Why Generalists Triumph in a Specialized World".
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.