Waves and Stress

Measuring the mechanical strength of a material at the nanoscale is challenging . If the object we are measuring happens to be a two-dimensional material, the task amazingly difficult. But people at Castellanos-Gómez Lab are really smart. They’ve adapted a method (already used with organic thin films) to determine these materials Young Modulus that, apart from other advantages, does not require the material to be freely suspended.

To make a long story short, they compress the material. Not been freely suspended, ripples appear all over the material. The wavelength of this ripples depends only in the elastic properties of the film and the substrate, so voilá! Frankly, much easier to explain than to perform.

These results were published in Advanced Materials.

To illustrate it, and requested by Dr. Andrés Castellanos-Gómez, we did this image that made it to the back cover of Advanced Materials.

NanoCosmos: the beginning

About 4 years ago Prof. Jose Ángel Martín Gago approached me to talk me about the NANOCOSMOS project. As they explain in their website, “NANOCOSMOS will take advantage of the new observational capabilities (increased angular resolution) of the Atacama Large Millimeter/submillimeter Array (ALMA) to unveil the physical and chemical conditions in the dust formation zone of evolved stars”.  Simply put, they are studying the debris stars create and the role this dust plays in the life/death recycling story of the universe.

This is a huge ERC funded project directed by Prof. José Cernicharo which has put together research groups from Spain and France.

And this is where Natalia Ruiz Zelmanovitch (Public Information Officer of the project) appears. She happens to be the most-committed-with-outreach-and-dissemination-of-science I’ve ever met. And she wants to tell the story of the NANOCOSMOS project. And she wants to tell it right.

She is behind the production of “NANOCOSMOS: un viaje a lo pequeño.” Here you can watch the trailer:

Scixel has been in charge of the 3D visualizations of the space: stars, nebulae, galaxies and planetary systems. We have been working with the Nanocosmos people for a few years now and I can tell you, if I know Natalia enough, this is just the beginning. So, stay tunned!

Mapping stress at the nanoscale

Stress is the main cause of failure in mechanical and electronic devices incorporating thin films. At the same time, our knowledge of stress at the nanoscale, happens to be very limited and one of the reasons is that we have no access to the measurement of stress at this tiny scale.

And this is what Celia Polop, Enrique Vasco, Alma P. Perrino and Ricardo García (Universidad Autónoma de Madrid and Material Science Institute of Madrid-CSIC) have solved. They’ve just presented a novel method to map stress on surfaces with a sub 10nm resolution. This method, supported by finite element simulations, has allowed them to map stress on polycrystalline gold films.

We made this image (featured in Nanoscale) illustrating their work, strongly supported by Enrique Vasco and Celia Polop.