Field Effect, now in 2D!

Despite his age, Dr. Mario Lanza has a long experience and deep knowledge on the physics and development of micro and nanoelectronic devices. In this recent article he an his coworkers discuss “the main challenges and potential solutions towards the fabrication of field effect transistors with 2D semiconducting channels”. In particular, there is a useful analysis on how this technology, now dealing with sizes that approach the interatomic distances, could be implemented in the current semiconductor industry.

This picture we did for him was featured on the cover of Advanced Functional Materials.

Quantum coherence stability

Quantum technologies building on solid-state spin systems, as those used in quantum computing and quantum internet, require unprecedented levels of stability. Even small fluctuations in ambient magnetic field messes up with the coherence time of these systems. So for these technologies to have any future we first have to learn how to stabilize and protect individual quantum ensembles. Doctor (congratulations on that) Johannes Koelbl at Basel University, has spent quite some time dealing with this challenge.

 

In this picture we made for him it is shown a Nitrogen-Vacancy center spin embedded in a diamond mechanical cantilever. As Dr. Koelbl explains: “To enhance its coherence properties, the spin is driven by both a time-varying strain field and microwave magnetic fields. The strain field is caused by harmonic oscillations of the cantilever, while the nearby wire serves as a near-field microwave source. Optical manipulation allows detecting the improved spin properties.”

He has chosen this picture to appear in the cover of his thesis manuscript.

Weighing tumorigenic cells

One of the last papers published by BioNanoMechanics Lab mixes biology, medicine, mechanics and optics. They have developed an efficient method to tell tumorigenic cells from healthy ones using mechanical and optical techniques. This group of researchers seems to be truly committed with the removal of the border between physics and biology.

The resonance frequency of an object ( ωf ) is amazingly sensitive to nearly everything, and in particular, to changes in mass of the object. Now imagine you built a very small glass capillary tube, you fill it with water with cells suspended in it. In this conditions, ωf  will depend somehow in the mass of the cells. Now lets say, tumorigenic and healthy cells have different masses: there you have it! Your oscillating microcapillary tube is now a cancer detector.

Of course it is not that easy. To be sure they are measuring single cells and not clusters of cells or other suspended elements, they’ve added an optical probe, that produces, together with the mechanical data, a simultaneous optical measurement.

In summary, they’ve developed a novel, fast, efficient and beautifully ingenious way to detect tumorigenic cells.

This picture we did under the supervision of Montserrat Calleja and Alberto Martín was featured on the cover of ACS Sensors in December 2019.

pH‐dependent switches

We’ve had the fortune to work for researchers that study the drug delivery process. Ana Pizarro at IMDEA Nanociencia is focusing her efforts in the understanding of how and when to activate this drugs. In an article written for Chemistry A European Journal in 2017 she showed how to control in‐tumor drug activation via pH.

Innactive Ruthenium(II) arene complexes are innocuous and unable to interact with their molecular target. However, at a certain proton concentration this molecules are activated making it possible for them to bind to DNA.

Tumors happen to have a different pH than their environment making this complexes a possible option as drug switches.

I inexcusably forgot this work, considering the importance I give to medical related researchs. Her work was featured in the cover of the journal.

 

Self-defending implants

The manufacturing of bone implants involves a great deal of problems which are still to be solved. One of the most important challenges are implant-associated infections which make the development of implants with intrinsic antibacterial properties a pressing issue. This is precisely what they are trying to achieve at the Department of Biomechanical Engineering (TU Delft).

They’ve just studied the effect of both Ag and copper nanoparticles on TiO2 surfaces and its effectiveness as antibacterial and osteoconductive biomaterials. In fact they’ve observed that these materials “have a strong antibacterial behavior against both planktonic and adherent bacteria in vitro conditions.”

These results have been published in the Journal of Materials Chemistry B and have been featured on the cover. We designed the picture under the supervision of Ingmar A. J. van Hengel, first author of the paper. 

Influenza: the secret of its success

We, as human’s, are pretty familiar with the influenza A virus, so it is confusing to know how much there is still to learn about it. And researchers from CSIC have just reduced our ignorance about it a little bit more. Together with researchers from Stockholm University, CNRS, and Institut Pasteur, and using cryoelectron microscopy, they’ve  unveiled the transcription mechanism of this virus. This is important, among other reasons, to understand why this virus is so successful. And its been published in Nature Microbiology.

The molecules responsible for transcription are the ribonucleoproteins (RNPs). This RNPs which are extremely flexible, adopt a double helical conformation. In this configuration, the RNA, attached to the RNPs, slides in a sort of worm drive fashion. This process can be seen in the video we made for them as supplementary information for their paper. As put by the researchers, “the flexibility of the viral RNPs is key and explains how the virus is able to create a big amount of proteins from a limited number of genes”.

We also attempted the cover of Nature with this picture.

I’ve never whined about not getting a cover, but there is always a first. I’ve had the privilege to follow this research for about two years, thanks to Jaime Martín-Benito, so I can’t but feel it as something personal. The discovery is amazingly important and the picture is really beautiful (idea of Jaime Martín-Benito, corresponding author of the paper). And it deserves to be shown! So here it is for your enjoyment.

Red light

A new small molecule, a hexabenzoovalene derivative, also called nanographene due to its similarities with the ubiquitous molecule, has been discovered to be a stable, bright, and efficient red emitter. This molecule has a highly distorted structure. This avoids aggregation, an important enemy of efficiency, thus leading to the possibility of fabricating highly emissive thin films. At the same time, it is electrochemically stable resulting in extrapolated high stabilities (~13.000 hours).

This work is the product of a collaboration between IMDEA Materials, IMDEA Nanociencia, both in Madrid and Ruprecht-Karls-Universität in Heidelberg.

This findings have been published in Nanoscale Horizons and this picture, designed under the supervision of Elisa Fresta (IMDEA Materials), first author of the paper, has been awarded with the cover of the journal.

 

Nanoscale thermal switches

Thermal management is of key importance in nanoscale devices that have the bad habit of heating up, thus affecting its performance. Prof. Pramod Reddy (University of Michigan) has a long experience dealing with heat transfer at the nanoscale [1][2].

Recently, at the Department of Mechanical Engineering, they’ve been working in a simple and beautiful idea: a thermal switch that employs nanoscale effects that appear when heat is transferred between two tiny membranes. By bringing a third object (modulator) closer to the membranes, the heat transfer between them can be controlled. What we have here is a multi-body effect  that could be used as an efficient way to actively control of heat transfer at the nanoscale.

This work has been published in Nature Nanotechnology and Prof. Reddy asked us to make this picture to illustrate these promising findings.

Shake, Graphene

There is a lot going on in Jorge Pedrós last paper: surface acoustic waves (SAWs), dynamic strain, Raman scattering and optical phonons. At the Instituto de Sistemas Optoelectrónicos y Microtecnología, UPM (together with the Paul Drude Institute in Berlin and the State University of Campinas), they’re using SAWs to modulate the properties of graphene. They’ve proven that “SAWs are powerful tools for modulating the optical and vibrational properties of supported graphene by means of the high-frequency localized deformations tailored by the acoustic transducers, which can also be extended to other 2D systems”. Straintronics, as this new technique is called, employs strain to change and modulate different properties of materials.

We did this picture, under the supervision of Jorge Pedrós, to illustrate their research.

Spin, keep it together!

The spin of electrons is the best way to storage information… theoretically. This property of electrons is so subtle and erratic that it is virtually impossible to use them in an efficient way. But as everything in science, this is changing.

At Kavli Institute of Nano­science at TU Delft,  they’re starting to control the behavior of spins. By using a thin silver thread, and a 2D material made of tungsten disul­fide, “and using circu­larly polarised light, they’ve created excitons with a specific rota­tional direction”. And what’s more impressive, this experiment works at room temperature. And finally, to make it more interesting, in this process there is no flow of electrons involved, meaning that there is a global energy reduction in the storage of data.

We made this picture to illustrate their experiment.