On pandemics, flexible spikes and mechanical stability

The SARS-CoV-2 is covered by a layer of “spikes” whose mobility (yet to be determined) has been proposed to be related to the infection process. Miklós S. Z. Kellermayer et al. (Semmelweis University, Budapest) “by imaging and mechanically manipulating individual, native SARS-CoV-2 virions with AFM” have proved that this layer is in fact dynamic. The virions show also a remarkable resistance to deformation and they’re able to recover from extreme mechanical deformations. You can read the details in their paper published in Nanoletters.

As a side note, the AFM experimental images they’ve published are just beautiful.

To illustrate the experiments we made this picture, under the close supervision of first author, Bálint Kiss, which has been featured in the cover of Nanoletters.

 

Good Vibrations

Today we want to talk about light and molecular vibrations coupling. It is known that infrared light can interact with matter through the molecules natural vibrations. What it was not so well known is that this coupling between light and matter can be so strong that it can change the material properties. But this strong-coupling-landscape has yet to be explored.

Researchers from CIC nanoGUNE BRTA (San Sebastian, Spain), the Donostia International Physics Center (San Sebastián, Spain) and the University of Oviedo (Spain) have employed a spectroscopic nanoimaging technique to achieve this strong coupling. By using “a particularly strong compression of infrared light” and a “thin layer of hexagonal boron nitride” they’ve explored in real space “how the phonon polaritons couple with the molecular vibrations” of organic molecules.

Their findings, published in Nature Photonics could have an impact in molecules detection technologies but more importantly, it opens a door to the study of quantum aspects of strong vibrational coupling.

This picture we did under the supervision of Andrei Bylinkin (first author) has been featured in the cover of Nature Photonics.

Boosting our batteries

Up to this point we’ve all recognized graphene’s omnipotence. This time we bring it to the website in its role of “energy storage enhancer”. At CIC energiGUNE, Daniel Carriazo et al., have just shown how functionalizing  graphene with phosphate groups in lithium-ion capacitors, highly improves both their power but more interestingly, they cyclability.

This picture, made under the supervision of Daniel Carriazo, has appeared as the cover feature at Batteries and Supercaps.

A sustainable Internet of Things ecosystem

A future of wireless self‐powered devices is upon us. The number of sensors and devices in our close environment is growing fast. And so does its energy demand.

 

In his last paper, Vincenzo Pecunia proposes the use of indoor photovoltaics: a clean sustainable way to fulfill this demand with lead‐free (and thus, non toxic) perovskite‐inspired materials. In particular Pecunia and co-workers, have studied two materials, BiOI and Cs3Sb2ClxI9‐x which happen to be really bad at harvesting sun light but present high efficiencies under indoor light conditions.

This research opens a door to the study of more efficient, non-toxic perovskite‐inspired materials and a sustainable future.

Under close supervision of Dr. Pecunia we made this picture that has been featured as the cover of Advanced Energy Materials.

 

Single-molecule junctions and atomic contacts

Dr. Laura Rincón made her thesis defense in August 2009. The manuscript, titled Conductance, thermopower and thermal conductance measurements in single-molecule junctions and atomic contacts, is a study on the properties of these contacts in the context of molecular electronics and thermoelectricity. The defense was recently awarded with the Best Experimental Thesis GEFES award.

Dr. Rincón used this picture we made years ago on request of her PhD advisor Prof. Nicolás Agrait.

Visualizing charges

Visualizing the behaviour of charge carriers will benefit the design and functionality of semiconductor devices. This, which seems a great idea, seems equally unattainable. However, at Delft University of Technology (The Netherlands) they’re famous for not having any respect for seemingly unattainable challenges.

Jacob P. Hoogenboom et al. have developed a technique to visualize “fast bulk charge recombination and slow trapping”. These two competing processes involve fast free charges and slow, more stationary, trapped charges. The device, a Lock-in ultrafast scanning electron microscope has enabled, in a proof of concept, a deep analysis of trap states on GaAs surfaces. And as they conclude, this technique will allow the study of “carrier transport in and across heterojunctions, underneath nanostructured surfaces, or at edges or layer transitions in two-dimensional materials”.

This image we made under the close supervision of Mathijs Garming (first author of the paper), has been featured as the cover of The Journal of Physical Chemistry Letters.

Long live the Nucleobase!

Multiple medical and biological sensors and targeted drug delivery are based in the functionalization of nanoparticles (NPs) with biomolecules. The role of the NPs is to enhance the optical response of the target surroundings. But this enhancement comes with a huge risk: this same radiation can severily damage DNA or RNA producing mutations.

Johannes Feist (UAM) together with groups from the University of Modena and the University of Munich, have studied in which conditions these NPs can act as a protection for the biomolecules (in this case Uracil) while being effective in their sensing/therapeutic function. And importantly, the results proposed in their research can be easily implemented with the current nanophotonic technology.

This paper, published in the Journal of Physical Chemistry Letters, has been recognized with the cover we designed together with the supervision of Dr. Feist.

Optoelectronics: MoS2 on canvas.

If I understand it correctly (and I’m probably not), Andres Castellanos is not only making interesting discoveries in condensed matter physics. He and his collaborators (Kavli Institute of Nanoscience and the University of Teheran) are also actively working on making it easier for others to make advances on this area. How? By making easier to use, cheaper technology.

A good example is their “under 100 bucks probe station”. Another one is this recent paper where they fabricate paper-supported semiconducting devices by painting on them with MoS2 crystal. Let me repeat this last statement: BY PAINTING ON THEM WITH MoS2. They’ve not only proved this methodology works and produces perfectly working devices. They also show how this approach could open the path for the construction of cheaper sensors.

The picture we did for them to illustrate this process has been featured in the cover of Nanoscale.

Hedgehog spin textures

Magnetic skirmions are quasiparticles which present extended configurations (or textures) of spins and their physics are of great interest since they could be used in spintronics as sensors or memory storage devices. Its manipulation and tailoring is thus of great importance.

In a recent work published in Nanoscale, a group led by Prof. Agustina Asenjo, report the stabilization of half hedgehog skyrmionic configuration in permalloy hemispherical nanodots, induced by the stray field of the MFM probe.

As the first author, Eider Berganza, explains, “this is a remarkable achievement due to soft magnetic nature of the permalloy and the absence of the choice of the material, which does not present magnetocrystalline anisotropy or Dzyaloshinskii–Moriya interaction, considered as necessary ingredients for the nucleation of skyrmions”.

 

This research, has been a huge collaborative effort that involved sample preparation, measurements and theoretical micromagnetic simulations in Spain, Germany and the US.

This image we did under the supervision of Eider Berganza and Miriam Jaafar (ICMM-CSIC) has been featured in the Cover of Nanoscale. Personally, has been the apex of a long and beautiful collaboration with old friends.

 

Polariton condensates’ propagation.

Polaritons are versatile quasiparticles that could be at the core of new technologies, since polariton devices have been proposed, such as polariton lasers, optical gates, transistors, spin-based elements and integrated circuits. Yet, their propagation depends strongly on the geometry of the pathway laid for them.

In a recent paper, Luis Viña, Dolores Martín, et al. in a huge collaborative research (Madrid, Jena, Würzburg, Saint-Petersburg, Reykjavik and Saint Andrews) have analyzed the Impact of the energetic landscape on polariton condensates’ propagation along a coupler”, published in Advanced Optical Materials.



The amount of technical challenges involved in this research is hard to grasp: from the manufacture of the guides to the experimental measurements, that require literally “taking pictures of light”.

We did this picture that was featured in the cover of Advanced Optical Materials, under close supervision of Dolores Martín and Luis Viña.