The synaptic connection

It is easy to understand how important the formation of correct synaptic connections is during neural circuitry formation. The Teneurin family of proteins promotes these connections between cells playing an essential role in neuron-neuron adhesion.

At the Kavli Institute of Nanoscience (TUDelft) together with the Utrecht University have resolved the dimeric ectodomain of human Teneurin4 structure with 2.7 Å resolution. In the world of proteins, structure is directly related to function. And this amazing research, which has been featured in the cover of EMBO Journal, supports the role for teneurins as a scaffold for macromolecular complex assembly and the establishment of cis- and trans-synaptic interactions to construct functional neuronal circuits.

We made this picture to illustrate the behaviour of Teneurin, closely advised by Dr. Dimphna Meijer.

Cool radio waves

How do you cool radio waves? Do waves have a temperature in the first place? Common waves are hot meaning they are noisy. There are multiple sources of noise in the generation process of waves and some of them are related to temperature. One of these sources, and probably the most difficult to remove, comes from the intrinsic random motion of atoms.

A possible solution would be to conventionally cool down the antennas that emit the waves. But even at temperatures of miliKelvin, the jiggling of atoms produce a significant amount of noise.

A group of researchers at TuDelft led by Prof. Gary Steel have managed to cool radio waves to their quantum ground state and the process is as surprising as it is difficult to grasp. They’ve placed a circuit close to the antenna that gets coupled to it via its magnetic field. This circuit then acts as a “vaccum cleaner” that absorbs entropy from the antenna cooling it down.

This cooling process and subsequent noise reduction, published in Science Advances, will be of the utmost importance in detectors in a wide range of devices and purposes: from NMR to astronomical detectors.

We made this animation with the help of Dr. Ines Rodrigues (first author of the paper) and Prof. Gary Steele to illustrate the process.


Atomic dialogues

Here I bring you another scientific milestone performed in TUDelft and published in Science. This time is about single atoms exchanging quantum information and in the way, unveiling quantum mechanics at a fundamental level. Veldman et al. have been spying single magnetic atoms and they’ve observed their reaction when one of their neighbours received an electric pulse. And this is not an easy task.

First, Sander Otte’s team has to built this “neighbourhood” of atoms by placing them close to each other at a distance at which they’re able to “feel” each other’s magnetic moments. And then the fun part starts: they send a pulse at one of the atoms and observe its neighbour’s reaction. This starts a sort of a conversation between the two atoms, an interchange of quantum information. A kind of a dance in which the two atoms swap their magnetic moment back and forth.

This observation has some interesting implications: first, it means another step in the understanding of qbits. But the inherent violence of the process (this aggressive non-coherent electric pulse) could mean that we might not need to be so careful at initializing quantum states.

To illustrate this conversation we made this picture under the close supervision of Prof. Sander Otte.

Invoking Spin Waves into the real world

Magnetic resonance imaging (MRI) has long been used as a non invasive detection technique in scientific research, industry and medicine. However, its low resolution (in the order of millimeters) makes it useless for nanotechnology applications despite its huge potential.

And this is were researchers from TU Delft, Leiden University, Tohoku University and the Max Planck Institute come into play. They’ve recently developed an MRI-like technique able to imaging magnetic waves with sub-micron resolution. Among its capacities, it is able to imaging spin waves through opaque materials such as the metal wiring on a chip. And also, it has the sensitivity to detect spin waves in magnets that are only a single atom thick. This work has been published in Science Advances.

If you’ve read my posts, you’ll know I don’t usually value my own images. But in this occasion I have to. This might be the most elegant picture I’ve made up to date. And for that, I have to thank the direction of Iacopo Bertelli and Toeno Van der Sar.


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.

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. 

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.

Cocaine detection

Cocaine happens to be one of the most illicit drugs in Europe and US. Yet, estimations say there are around 17 million users worldwide. This together, makes important the detection of cocaine and having devices able to precisely measure a wide range of cocaine concentrations in street samples. At TU Delft, together with the Netherlands Forensic Institute Lukasz Poltorak et al. have proposed a successful method which allows not only the detection of very different concentrations of cocaine but also the analysis and detection of cutting agents.

Industrializing entanglement

It is hard to imaging the making of the first transistor, now that we make them by the millions. How did we went from making a single, precious and delicate transistor to its mass production?

In a way we are living that very same moment with quantum entanglement (QE). Just months ago the QE of two particles meant a huge achievement. Today, ‘on demand’ entanglement links have been reported in Nature. Quantum entanglement is the pillar of a secure quantum internet. So a way to establish fast and stable links between particles is needed. Thanks to Prof. R. Hanson (QuTech and Kavli Institute of Nanoscience, TuDelft), we are at the verge of QE mass production.

As it is explained at TuDelft website “First of all, they demonstrated a new entanglement method. This allows for the generation of entanglement forty times a second between electrons at a distance of two metres. Peter Humphreys, an author of the paper, emphasises: ‘This is a thousand times faster than with the old method.’ In combination with a smart way of protecting the quantum link from external noise, the experiment has now surpassed a crucial threshold: for the first time, entanglement can be created faster than it is lost.”

Michel van Baal kindly asked for our help in the making of a picture of quantum network. We feel kind of proud been close witnesses of these important discoveries.

Packing DNA

Eukariotic cells face a hard to picture space problem: to pack a 2 meter long molecule into a 6 microns in diameter sphere. Not only that, the cell must be able to pack and unpack this DNA locally in order to perform its functions.

A protein called Condensin has been long known to be related to the DNA packing process, but until last year, the way this protein worked was still a mystery. Prof. Cees Dekker has directed the research that has unveiled this secret. For us, non biologist it is hard to understand how important this is and its repercussion, but the fact that it has been published in Science gives us a hint. This work is a collaboration between TuDelft (Netherlands) and EMBL (Germany).

Thanks to this research we know now how Condensin traps the DNA and uses its ring to drag the DNA forming a loop. Together with the people of TuDeflt we made this video explaining the motor function of this protein.

We are particularly proud of the music piece… hope its epicity expresses both the importance of the finding and the pride we’ve felt when they let us participate in the project.