Bioinspired, biomimetic stimulation for the next generation of neuroprosthetics

ETH researchers have developed a prosthetic leg that communicates with the brain via natural signals. (Photograph: Keystone) Courtesy: ETH Zurich

A February 21, 2024 ETH Zurich press release by Ori Schipper (also on EurekAlert) announces a ‘nature-inspired’ or bioinspired approach to neuroprosthetics,

Prostheses that connect to the nervous system have been available for several years. Now, researchers at ETH Zurich have found evidence that neuroprosthetics work better when they use signals that are inspired by nature.

In brief

*Neuroprostheses are electro-​mechanical devices that are connected to the nervous system. As yet, these are unable to provide natural communication with the brain. Instead, they often evoke artificial, unpleasant sensations, similar to a feeling of tingles over the skin.
*This paraesthesia might be caused by overstimulation of the nervous system. ETH Zurich researchers together with colleagues in Germany, Serbia and Russia have proposed that neuroprosthetics should transmit biomimetic signals that are easier for the brain to understand.
*These new findings are relevant to arm and leg prostheses as well as various other aids and devices, including spinal implants and electrodes for brain stimulation. 

A few years ago, a team of researchers working under Professor Stanisa Raspopovic at the ETH Zurich Neuroengineering Lab gained worldwide attention when they announced that their prosthetic legs had enabled amputees to feel sensations from this artificial body part for the first time. Unlike commercial leg prostheses, which simply provide amputees with stability and support, the ETH researchers’ prosthetic device was connected to the sciatic nerve in the test subjects’ thigh via implanted electrodes.

This electrical connection enabled the neuroprosthesis to communicate with the patient’s brain, for example relaying information on the constant changes in pressure detected on the sole of the prosthetic foot when walking. This gave the test subjects greater confidence in their prosthesis – and it enabled them to walk considerably faster on challenging terrains. “Our experimental leg prosthesis succeeded in evoking natural sensations. That’s something current neuroprostheses are mainly unable to do; instead, they mostly evoke artificial, unpleasant sensations,” Raspopovic says.

This is probably because today’s neuroprosthetics are using time-​constant electrical pulses to stimulate the nervous system. “That’s not only unnatural, but also inefficient,” Raspopovic says. In a recently published paper, he and his team used the example of their leg prostheses to highlight the benefits of using naturally inspired, biomimetic stimulation to develop the next generation of neuroprosthetics.

Model simulates activation of nerves in the sole

To generate these biomimetic signals, Natalija Katic – a doctoral student in Raspopovic’s research group – developed a computer model called FootSim. It is based on data collected by collaborators in Canada, who recorded the activity of natural receptors, named mechanoreceptors, in the sole of the foot while touching different points on the feet of volunteers with a vibrating rod.

The model simulates the dynamic behaviour of large numbers of mechanoreceptors in the sole of the foot and generates the neural signals that shoot up the nerves in the leg towards the brain – from the moment the heel strikes the ground and the weight of the body starts to shift forward to the outside of the foot until the toes push off the ground ready for the next step. “Thanks to this model, we can see how semsory receptors from the sole, and the connected nerves, behave during walking or running, which is experimentally impossible to measure” Katic says.

Information overload in the spinal cord

To assess how closely the biomimetic signals calculated by the model correspond to the signals emitted by real neurons, Giacomo Valle – a postdoc in Raspopovic’s research group – worked with colleagues in Germany, Serbia and Russia on experiments with cats, whose nervous system processes movement in a similar way to that of humans. The experiments took place in 2019 at the Pavlov Institute of Physiology in St. Petersburg and were carried out in accordance with the relevant European Union guidelines.

The researchers implanted electrodes, connecting some to the nerve in the leg and some to the spinal cord to discover how the signals are transmitted through the nervous system. When the researchers applied pressure to the bottom of the cat’s paw, thereby evoking the natural neural response that occurs when a cat takes a step, the peculiar pattern of activity recorded in the spinal cord did indeed resemble the patterns that were elicited in the spinal cord when the researchers stimulated the leg nerve with biomimetic signals.

By contrast, the conventional approach of time-​constant stimulation of the sciatic nerve in the cat’s thigh elicited a markedly different pattern of activation in the spinal cord. “This clearly shows that the commonly used stimulation methods cause the neural networks in the spine to be flooded with information,” Valle says. “This information overload could be the reason for the unpleasant sensations or paraesthesia reported by some users of neuroprosthetics,” Raspopovic adds.

Learning the language of the nervous system

In their clinical trial with leg amputees, the researchers were able to show that biomimetic stimulation is superior to time-​constant stimulation. Their work clearly demonstrated how the signals that mimicked nature produced better results: not only were the test subjects able to climb steps faster, they also made fewer mistakes in a task that required them to climb the same steps while spelling words backwards. “Biomimetic neurostimulation allows subjects to concentrate on other things while walking,” Raspopovic says, “so we concluded that this type of stimulation is more naturally processed and less taxing on the brain.”

Raspopovic, whose lab forms part of the ETH Institute of Robotics and Intelligent Systems, believes that these new findings are not only relevant to the limb prostheses he and his team have been working on for over half a decade. He argues that the need to move away from unnatural, time-​constant stimulation towards biomimetic signals also applies to a whole series of other aids and devices, including spinal implants and electrodes for brain stimulation. “We need to learn the language of the nervous system,” Raspopovic says. “Then we’ll be able to communicate with the brain in ways it really understands.”

Here’s a link to and a citation for the paper,

Biomimetic computer-to-brain communication enhancing naturalistic touch sensations via peripheral nerve stimulation by Giacomo Valle, Natalija Katic Secerovic, Dominic Eggemann, Oleg Gorskii, Natalia Pavlova, Francesco M. Petrini, Paul Cvancara, Thomas Stieglitz, Pavel Musienko, Marko Bumbasirevic & Stanisa Raspopovic. Nature Communications volume 15, Article number: 1151 (2024) DOI: https://doi.org/10.1038/s41467-024-45190-6 Published: 20 February 2024

This paper is open access.

It was a bit of a surprise to see mention of some Canadian collaborators with regard to the earlier work featuring FootSim, a computer model Here’s a link to and a citation to that paper, this version is housed at ETH Zurich,

Modeling foot sole cutaneous afferents: FootSim by Natalija Katic, Rodrigo Kazu Siqueira, Luke Cleland, Nicholas Strzalkowski, Leah Bent, Stanisa Raspopovic, and Hannes Saal. Originally published in: iScience 26(1), DOI https://doi.org/10.1016/j.isci.2022.105874 Publication date: 2023-01-20 Permanent link: https://doi.org/10.3929/ethz-b-000591102

This paper too is open access.

Félicitations! Federico Rosei, Canadian (Québec) researcher, receives international recognition

If you search for Federico Rosei’s name here, you will find more than one posting (this one from January 5, 2023, Can I have a beer with those carbon quantum dots?, being one of my favourites)..

Here’s more about the latest honour bestowed on the much lauded Canadian scientist, from a May 8, 2024 Institut national de la recherche scientifique (INRS) news release (also on EurekAlert), Note: Links have been removed,.

Federico Rosei, a professor at the Institut national de la recherche scientifique (INRS) in materials science and nanotechnology, has been appointed Materials Research Society (MRS) Fellow 2024 for “his leadership in the nanomaterials synthesis and characterization and his sustained international efforts in service, mentoring and outreach in the field.”

He thus becomes the first researcher in Quebec and the third across Canada to become a Fellow of this prestigious professional society in the field of advanced materials.

“I am honoured to become an MRS Fellow. This is an important recognition for scientists, like me, who work in the field of nanomaterials. I would like to dedicate this distinction to the young researchers who have worked in my team and contributed to the advancement of knowledge in the field.”Federico Rosei, Professor at INRS and holder of UNESCO Chair in Materials and Technologies for Energy Conversion, Saving and Storage

A world-renowned researcher in the fields of nanoscience and nanotechnology, Federico Rosei has been recognized by the MRS for his work in characterizing nanomaterials, in particular multifunctional materials and their integration in optoelectronic devices.

The MRS is a leading interdisciplinary professional society in the field of advanced materials that “promotes communication for the advancement of interdisciplinary materials research and technology to improve the quality of life.” Founded in 1973, the Society has around 12,000 members from over 90 countries. Full members, or “Fellows,” are recognized for their “sustained and distinguished” contributions to advanced materials research and can serve as thought leaders to help guide and promote the development of the field.

International recognition of Canadian excellence

Professor Rosei is also one of 21 Canadian recipients of prestigious international research awards in 2023, according to the Global Excellence Initiative. In particular, he has distinguished himself through his interdisciplinary approach to promising work in nanotechnology.

Launched in 2012, the Global Excellence Initiative recognizes the contributions of Canadian researchers by identifying and supporting candidates for prestigious national and international awards. The researcher is the recipient of the only 2023 Guggenheim Fellowship in the engineering category. These Fellowships are awarded to mid-career individuals who have demonstrated exceptional research or artistic abilities, and who show great promise for the future.

His research on very small objects, which exhibit quantum effects that do not occur at the macro scale, could lead to new materials that support technological breakthroughs in energy, electronics and health.

“When you work at such small dimensions, the boundaries between disciplines are quite blurred,” explains Professor Rosei. “So what we do is considered physics, but also chemistry and materials science, and even engineering. That’s one of the fascinating aspects of my work: I get to collaborate with people from different backgrounds and exchange ideas and perspectives. This in turn brings about insights that would be difficult to obtain if we worked independently.”

 Federico Rosei has just been named a Fellow of the Canadian Association of Physicists (CAP) in recognition of his outstanding achievements in the field of materials physics, in particular multiferroic materials and quantum dots, combined with exceptional mentoring of trainees. He is also recognized for his international leadership in promoting excellence in Canadian physics worldwide.

“We are proud to have Professor Rosei among us, an inspiring researcher for the INRS community. In addition to being a scientist of international renown for his achievements and leadership, he is also recognized for his remarkable contribution to training the next generation of scientists in Quebec and internationally. Here’s to the next generation of scientists in Quebec and around the world. Congratulations!Isabelle Delisle, Interim Scientific Director, INRS

Professor Rosei is also the scientific head of the Nanofemtosecond Laboratory at INRS  Energie Matériaux Télécommunications Research Centre. Holder of the Canada Research Chair in Nanostructured Materials from 2016 to 2023, the researcher boasts an international reputation, and the recognition of his peers has translated into numerous awards, honours and distinctions in several disciplines over the years, including chemistry, education, engineering and physics.

Again, congratulations to Federico Rosei!

Math + data + history lead to cliodynamics and history crisis detection

This February 18, 2024 essay by Daniel Hoyer, senior researcher, historian, and complexity scientist at the University of Toronto for The Conversation, discuses history as scientific data, Note: Links have been removed,

American humorist and writer Mark Twain is believed to have once said, “History doesn’t repeat itself, but it often rhymes.”

I’ve been working as a historian and complexity scientist for the better part of a decade, and I often think about this phrase as I follow different strands of the historical record and notice the same patterns over and over.

My background is in ancient history. As a young researcher, I tried to understand why the Roman Empire became so big and what ultimately led to its downfall. Then, during my doctoral studies, I met the evolutionary biologist turned historian Peter Turchin, and that meeting had a profound impact on my work.

I joined Turchin and a few others who were establishing a new field – a new way to investigate history. It was called cliodynamics after Clio, the ancient Greek muse of history, and dynamics, the study of how complex systems change over time. Cliodynamics marshals scientific and statistical tools to better understand the past.

The aim is to treat history as a “natural” science, using statistical methods, computational simulations and other tools adapted from evolutionary theory, physics and complexity science to understand why things happened the way that they did.

By turning historical knowledge into scientific “data”, we can run analyses and test hypotheses about historical processes, just like any other science.

Hoyer’s essay is fascinating and I can’t really do it justice with a few excerpts but hopefully these will tempt you into reading more of his and his colleagues’ work, from the February 18, 2024 essay.

Since 2011, my colleagues and I have been compiling an enormous amount of information about the past and storing it in a unique collection called the Seshat: Global History Databank. Seshat involves the contribution of over 100 researchers from around the world.

We create structured, analysable information by surveying the huge amount of scholarship available about the past. For instance, we can record a society’s population as a number, or answer questions about whether something was present or absent. Like, did a society have professional bureaucrats? Or, did it maintain public irrigation works.

Our goal is to find out what drove these societies into crisis, and then what factors seem to have determined whether people could course-correct to stave off devastation.

But why? Right now, we are living in an age of polycrisis – a state where social, political, economic, environmental and other systems are not only deeply interrelated, but nearly all of them are under strain or experiencing some kind of disaster or extreme upheaval.

Pouring through the historical record, we have started noticing some very important themes rhyming through history. Even major ecological disasters and unpredictable climates are nothing new.

One of the most common patterns that has jumped out is how extreme inequality shows up in nearly every case of major crisis. When big gaps exist between the haves and have-nots, not just in material wealth but also access to positions of power, this breeds frustration, dissent and turmoil.

“Ages of discord”, as Turchin dubbed periods of great social unrest and violence, produce some of history’s most devastating events. This includes the US civil war of the 1860s, the early 20th-century Russian Revolution, and the Taiping rebellion against the Chinese Qing dynasty, often said to be the deadliest civil war in history.

All of these cases saw people become frustrated at extreme wealth inequality, along with lack of inclusion in the political process. Frustration bred anger, and eventually erupted into fighting that killed millions and affected many more.

Perhaps one of the most surprising things is that inequality seems to be just as corrosive for the elites themselves. This is because the accumulation of so much wealth and power leads to intense infighting between them, which ripples throughout society.

My colleague, political scientist Jack Goldstone, came up with a theory to explain this [“gap between the wealthy who can afford services and the growing number who cannot”] in the early 1990s, called structural demographic theory. He took an in-depth look at the French Revolution, often seen as the archetypal popular revolt. Goldstone was able to show that a lot of the fighting and grievances were driven by frustrated elites, not only by the “masses”, as is the common understanding.

These elites were finding it harder and harder to get a seat at the table with the French royal court. Goldstone noted that the reason these tensions became so inflamed and exploded is because the state had been losing its grip on the country for decades due to mismanagement of resources and from all of the entrenched privileges that the elites were fighting so hard to retain.

If the past teaches us anything, it is that trying to hold on to systems and policies that refuse to appropriately adapt and respond to changing circumstances — like climate change or growing unrest among a population – usually end in disaster. Those with the means and opportunity to enact change must do so, or at least to not stand in the way when reform is needed.

Our goal as cliodynamicists is to uncover patterns – not just to see how what we are doing today rhymes with the past – but to help find better ways forward.

If you have the time, please do read Hoyer’s February 18, 2024 essay in its entirety (h/t February 19, 2024 news item on phys.org). The Seshat Global History Databank can be found here.

University of Waterloo researchers get one step closer to secure quantum communication on a global scale

A March 25, 2024 news item on phys.org announcds Canadian research into quantum communication, Note: Links have been removed,

Researchers at the University of Waterloo’s Institute for Quantum Computing (IQC) have brought together two Nobel prize-winning research concepts to advance the field of quantum communication.

Scientists can now efficiently produce nearly perfect entangled photon pairs from quantum dot sources. The research, “Oscillating photonic Bell state from a semiconductor quantum dot for quantum key distribution,” was published in Communications Physics

A March 25, 2024 University of Waterloo news release (also on EurekAlert), which originated the news item, delves further into the topic of quantum physics and communication,

Entangled photons are particles of light that remain connected, even across large distances, and the 2022 Nobel Prize in Physics recognized experiments on this topic. Combining entanglement with quantum dots, a technology recognized with the Nobel Prize in Chemistry in 2023, the IQC research team aimed to optimize the process for creating entangled photons, which have a wide variety of applications, including secure communications.

“The combination of a high degree of entanglement and high efficiency is needed for exciting applications such as quantum key distribution or quantum repeaters, which are envisioned to extend the distance of secure quantum communication to a global scale or link remote quantum computers,” said Dr. Michael Reimer, professor at IQC and Waterloo’s Department of Electrical and Computer Engineering. “Previous experiments only measured either near-perfect entanglement or high efficiency, but we’re the first to achieve both requirements with a quantum dot.”

By embedding semiconductor quantum dots into a nanowire, the researchers created a source that creates near-perfect entangled photons 65 times more efficiently than previous work. This new source, developed in collaboration with the National Research Council of Canada in Ottawa, can be excited with lasers to generate entangled pairs on command. The researchers then used high-resolution single photon detectors provided by Single Quantum in The Netherlands to boost the degree of entanglement.

“Historically, quantum dot systems were plagued with a problem called fine structure splitting, which causes an entangled state to oscillate over time. This meant that measurements taken with a slow detection system would prevent the entanglement from being measured,” said Matteo Pennacchietti, a PhD student at IQC and Waterloo’s Department of Electrical and Computer Engineering. “We overcame this by combining our quantum dots with a very fast and precise detection system. We can basically take a timestamp of what the entangled state looks like at each point during the oscillations, and that’s where we have the perfect entanglement.”

To showcase future communications applications, Reimer and Pennacchietti worked with Dr. Norbert Lütkenhaus and Dr. Thomas Jennewein, both IQC faculty members and professors in Waterloo’s Department of Physics and Astronomy, and their teams. Using their new quantum dot entanglement source, the researchers simulated a secure communications method known as quantum key distribution, proving that the quantum dot source holds significant promise in the future of secure quantum communications.

Here’s a link to and a citation for the paper,

Oscillating photonic Bell state from a semiconductor quantum dot for quantum key distribution by Matteo Pennacchietti, Brady Cunard, Shlok Nahar, Mohd Zeeshan, Sayan Gangopadhyay, Philip J. Poole, Dan Dalacu, Andreas Fognini, Klaus D. Jöns, Val Zwiller, Thomas Jennewein, Norbert Lütkenhaus & Michael E. Reimer. Communications Physics volume 7, Article number: 62 (2024)
DOI: https://doi.org/10.1038/s42005-024-01547-3 Published: 24 February 2024

This paper is open access.

3D printed nanocellulose for green architectural applications

It’s not happening next week but it is a promising step forward if you’re looking for nancellulose applications. From a February 7, 2024 news item on Nanowerk, Note: A link has been removed,

For the first time, a hydrogel material made of nanocellulose and algae has been tested as an alternative, greener architectural material. The study, from Chalmers University of Technology in Sweden and the Wallenberg Wood Science Center, shows how the abundant sustainable material can be 3D printed into a wide array of architectural components, using much less energy than conventional construction methods.

Caption: 3D printed nanocellulose upscaled for green architectural applications. Credit: Chalmers University of Technology | Emma Fry

A February 6, 2024 Chalmers University of Technology press release (also on EurekAlert but published February 7, 2024), which originated the news item,

The construction industry today consumes 50 percent of the world’s fossil resources, generates 40 percent of global waste and causes 39 percent of global carbon dioxide emissions. There is a growing line of research into biomaterials and their applications, in order to transition to a greener future in line with, for example, the European Green Deal.

Nanocellulose is not a new biomaterial, and its properties as a hydrogel are known within the field of biomedicine, where it can be 3D printed into scaffolds for tissue and cell growth, due to its biocompatibility and wetness. But it has never been dried and used as an architectural material before.

“For the first time we have explored an architectural application of nanocellulose hydrogel. Specifically, we provided the so far missing knowledge on its design-related features, and showcased, with the help of our samples and prototypes, the tuneability of these features through custom digital design and robotic 3D printing,” says Malgorzata Zboinska, lead author of the study from Chalmers University of Technology.

The team used nanocellulose fibres and water, with the addition of an algae-based material called alginate. The alginate allowed the researchers to produce a 3D printable material, since the alginate added an extra flexibility to the material when it dried.

Cellulose is coined as the most abundant eco-friendly alternative to plastic, as it is one of the byproducts of the world’s largest industries. “The nanocellulose used in this study can be acquired from forestry, agriculture, paper mills and straw residues from agriculture. It is a very abundant material in that sense,” says Malgorzata Zboinska.

3D printing and nanocellulose/ A resource efficient technique

The architectural industry is today surrounded by access to digital technologies which allows for a wider range of new techniques to be used, but there is a gap in the knowledge of how these techniques can be applied. According to the European Green Deal, as of 2030, buildings in Europe must be more resource-efficient, and this can be achieved through elevated reuse and recycling of materials, such as with nanocellulose, an upcycled, byproduct from industry. At the same time as buildings are to become more circular, cutting-edge digital techniques are highlighted as important leverages for achieving these goals.

“3D printing is a very resource efficient technique. It allows us to make products without other things such as dies and casting forms, so there is less waste material. It is also very energy efficient. The robotic 3D printing system we employ does not use heat, just air pressure. This saves a lot of energy as we are only working at room temperature,” says Malgorzata Zboinska.

The energy efficient process relies on the shear thinning properties of the nanocellulose hydrogel. When you apply pressure it liquifies allowing it to be 3D printed, but when you take away the pressure it maintains its shape. This allows the researchers to work without the energy intensive processes that are commonplace in the construction industry.

Malgorzata Zboinska and her team designed many different toolpaths to be used in the robotic 3D printing process to see how the nanocellulose hydrogel would behave when it dried in different shapes and patterns. These dried shapes could then be applied as a basis to design a wide array of architectural standalone components, such as lightweight room dividers, blinds, and wall panel systems. They could also form the basis for coatings of existing building components, such as tiles to clad walls, acoustic elements for damping sound, and combined with other materials to clad skeleton walls.

The future of greener building materials

“Traditional building materials are designed to last for hundreds of years. Usually, they have predictable behaviours and homogenous properties. We have concrete, glass and all kinds of hard materials that endure and we know how they will age over time. Contrary to this, biobased materials contain organic matter, that is from the outset designed to biodegrade and cycle back into nature. We, therefore, need to acquire completely new knowledge on how we could apply them in architecture, and how we could embrace their shorter life cycle loops and heterogenous behaviour patterns, resembling more those found in nature rather than in an artificial and fully controlled environment. Design researchers and architects are now intensely searching for ways of designing products made from these materials, both for function and for aesthetics,” says Malgorzata Zboinska.

This study provides the first steps to demonstrate the upscaling potentials of ambient-dried, 3D-printed nanocellulose membrane constructs, as well as a new understanding of the relationship between the design of the material’s deposition pathways via 3D printing, and the dimensional, textural, and geometric effects in the final constructs. This knowledge is a necessary stepping stone that will allow Malgorzata Zboinska and her team to develop, through further research, applications of nanocellulose in architectural products that need to meet specific functional and aesthetic user requirements.  

“The yet not fully known properties of novel biobased materials prompt architectural researchers to establish alternative approaches to designing these new products, not only in terms of the functional qualities, but also the acceptance from the users. The aesthetics of biobased materials are an important part of this. If we are to propose these biobased materials to society and people, we need to work with the design as well. This becomes a very strong element for the acceptance of these materials. If people do not accept them, we will not reach the goals of a circular economy and sustainable built environment”.

More about the research:

The research is presented in a paper: “Robotically 3D printed architectural membranes from ambient dried cellulose nanofibril-alginate hydrogel”, published in the journal Materials and Design.

The researchers involved in the study are Malgorzata A. Zboinska, Sanna Sämfors and Paul Gatenholm. The researchers were active at Chalmers University of Technology and the Wallenberg Wood Science Center, both in Sweden, at the time of the study.

This work was supported by Adlerbertska Research Foundation and Chalmers University of Technology’s Area of Advance Materials Science. The Knut and Alice Wallenberg Foundation is gratefully acknowledged for funding the Wallenberg Wood Science Center. The authors would also like to recognise the contribution of Karl Åhlund, who assisted in the robotic extrusion system development.

Fact box – previous research:

Printing with nanocellulose was first developed at Chalmers University of Technology within the Wallenberg Wood Science Center in 2015. This is the first time this technology is being scaled up towards applications in buildings.

Here’s a link to and a citation for the paper,

Robotically 3D printed architectural membranes from ambient dried cellulose nanofibril-alginate hydrogel by Malgorzata A. Zboinska, Sanna Sämfors, Paul Gatenholm. Materials & Design Volume 236, December 2023, 112472 DOI: https://doi.org/10.1016/j.matdes.2023.112472

This paper appears to be open access.

For the curious, here’s The European Green Deal.

Global gathering in Rwanda for 5th International Conference on Governmental Science Advice (INGSA2024): “The Transformation Imperative”

The 4th gathering was in Montréal, Québec, Canada (as per my August 31, 2021 posting). Unfortunately,this is one of those times where I’m late to the party. The 5th International Conference on Governmental Science Advice (INGSA2024) ran from May 1 – 2, 2024 bu there are some satellite events taking place over the next few days.

I’m featuring this somewhat stale news because it offers a more global perspective on science policy and government advisors, from the May 1, 2024 International Network for Government Science Advice (INGSA) news release (PDF and on EurekAlert),

What? 5th International Conference on Governmental Science Advice, INGSA2024, marking the 10th Anniversary of the creation of the International Network for Governmental Science Advice (INGSA) & first meeting held in the global south.

Where?   Kigali Convention Center, Rwanda: https://ingsa2024.squarespace.com/

When?    1 – 2 May, 2024.

Context: One of the largest independent gatherings of thought- and practice-leaders in governmental science advice, research funding, multi-lateral institutions, academia, science communication and diplomacy is taking place in Kigali, Rwanda. Organised by Prof Rémi Quirion, Chief Scientist of Québec and President of the International Network for Governmental Science Advice (INGSA), speakers from 39 countries[1] from Brazil to Burkina Faso and from Ireland to Indonesia, plus over 300 delegates from 65 countries, will spotlight what is really at stake in the relationship between science, societies and policy-making, during times of crisis and routine.

From the air we breathe, the cars we drive, and the Artificial Intelligence we use, to the medical treatments or the vaccines we take, and the education we provide to children, this relationship, and the decisions it can influence, matter immensely. In our post-Covid, climate-shifted, and digitally-evolving world, the importance of robust knowledge in policy-making is more pronounced than ever. This imperative is accompanied by growing complexities that demand attention. INGSA’s two-day gathering strives to both examine and empower inclusion and diversity as keystones in how we approach all-things Science Advice and Science Diplomacy to meet these local-to-global challenges.

Held previously in Auckland 2014, Brussels 2016, Tokyo 2018 and Montréal 2021, Kigali 2024 organisers have made it a priority to involve more diverse speakers from developing countries and to broaden the thematic scope. Examining the complex interactions between scientists, public policy and diplomatic relations at local, national, regional and international levels, especially in times of crisis, the overarching theme is: “The Transformation Imperative”.

The main conference programme (see link below)will scrutinise everything from case-studies outlining STI funding tips, successes and failures in our advisory systems, plus regional to global initiatives to better connect them, to how digital technologies and A.I. are reshaping the profession itself.

INGSA2024 is also initiating and hosting a range of independent side-events that, in themselves, act as major meeting and rallying points that partners and attending delegates are encouraged to maximise. These include, amongst others, events organised by the Foreign Ministries Science & Technology Advice Network (FMSTAN); the International Public Policy Observatory Roundtable (IPPO); the High-Level Dialogue on the Future of Science Diplomacy (co-organised by the American Association for the Advancement of Science (AAAS), the European Commission, the Geneva Science & Diplomacy Anticipator (GESDA), and The Royal Society); the Organisation of Southern Cooperation (OSC)meeting on ‘Bridging Worlds of Knowledge – Promoting Endogenous Knowledge Development;the Science for Africa Foundation, University of Oxford Pandemic Sciences Institute’s meeting on ‘Translating Research Into Policy and Practice’; and the African Institute of Mathematical Sciences (AIMS) ‘World Build Simulation Training on Quantum Technology’ with INGSA and GESDA. INGSA will also host its own internal strategy Global Chapter & Division Meetings.   

Prof Rémi Quirion, Conference Co-Chair, Chief Scientist of Québec and President of INGSA, has said that:

“For those of us who believe wholeheartedly in evidence and the integrity of science, recent years have been challenging. Mis- and disinformation can spread like a virus. So positive developments like our gathering here in Rwanda are even more critical. The importance of open science and access to data to better inform scientific integration and the collective action we now need, has never been more pressing. Our shared UN sustainable development goals play out at national and local levels. Cities and municipalities bear the brunt of climate change, but also can drive the solutions. I am excited to see and hear first-hand how the global south is increasingly at the forefront of these efforts, and to help catalyse new ways to support this. I have no doubt that INGSA’s efforts and the Kigali conference, which is co-led with the Rwandan Ministry of Education and the University of Rwanda, will act as a carrier-wave for greater engagement. I hope we will see new global collaborations and actions that will be remembered as having first taken root at INGSA2024”.

Hon. Gaspard Twagirayezu, Minister of Education of Rwanda has lent his support to the INGSA conference, saying:

“We are proud to see the INSGA conference come to Rwanda, as we are at a turning point in our management of longer-term challenges that affect us all. Issues that were considered marginal even five or ten years ago are today rightly seen as central to our social, environmental, and economic wellbeing. We are aware of how rapid scientific advances are generating enormous public interest, but we also must build the capabilities to absorb, generate and critically consider new knowledge and technologies. Overcoming current crisis and future challenges requires global coordination in science advice, and INGSA is well positioned to carry out this important work. It makes me particularly proud that INGSA’s Africa Chapter has chosen our capital Kigali as it’s pan-African base. Rwanda and Africa can benefit greatly from this collaboration.”

Ass. Prof.  Didas Kayihura Muganga, Vice-Chancellor, University of Rwanda, stated:

“What this conference shows is that grass-roots citizens in Rwanda, across Africa and Worldwide can no longer be treated as simple statistics or passive bystanders. Citizens and communities are rightfully demanding greater transparency and accountability especially about science and technology. Ensuring, and demonstrating, that decisions are informed by robust evidence is an important step.  But we must also ensure that the evidence is meaningful to our context and our population. Complex problems arise from a multiplicity of factors, so we need greater diversity of perspectives to help address them.   This is what is changing before our very eyes. For some it is climate, biodiversity or energy supply that matters most, for others it remains access to basic education and public health. Regardless, all exemplify humanity’s interdependence.”

Daan du Toit, acting Director-General of the Department of Science & Innovation of the Government of South Africa and Programme Committee Member commented:

INGSA has long helped build and elevate open and ongoing public and policy dialogue about the role of robust evidence in sound policy making. But now, the conversation is deepening to critically consider the scope and breadth of evidence, what evidence, whose evidence and who has access to the evidence? Operating on all continents, INGSA demonstrates the value of a well-networked community of emerging and experienced practitioners and academics working at the interfaces between science, societies and public policy. We were involved in its creation in Auckland in 2014, and have stayed close and applaud the decision to bring this 5th International Biennial Meeting to Africa. Learning from each other, we can help bring a wider variety of robust knowledge more centrally into policy-making. That is why in 2022 we supported a start-up initiative based in Pretoria called the Science Diplomacy Capital for Africa (SDCfA). The energy shown in the set-up of this meeting demonstrates our potential as Africans to do so much more together”.

INGSA-Africa’s Regional Chapter

INGSA2024 is very much ‘coming home’ and represents the first time that this biennial event is being co-hosted by a Regional Chapter. In February 2016, INGSA announced the creation of the INGSA-Africa Regional Chapter, which held its first workshop in Hermanus, South Africa. The Chapter has since made great strides in engaging francophone Africa, organising INGSA’s first French-language workshop in Dakar, Senegal in 2017 and a bi-lingual meeting as a side-event of the World Science Forum 2022, Cape Town.  The Chapter’s decentralised virtual governance structure means that it embraces the continent, but new initiatives, like the Kigali Training Hub are set to become a pivotal player in the development of evidence-to-policy ecosystems across Africa.

Dr M. Oladoyin Odubanjo, Conference Co-Chair and Chair of INGSA-Africa, outlined that:

“As a public health physician and current Executive Secretary of the Nigerian Academy of Sciences (NAS), responsible for providing scientific advice to policy-makers, I have learnt that science and politics share common features. Both operate at the boundaries of knowledge and uncertainty, but they approach problems differently. Scientists question and challenge our assumptions, constantly searching for empiric evidence to determine the best options. In contrast, politicians are most often guided by the needs or demands of voters and constituencies, and by ideology. Our INGSA-Africa Chapter is working at the nexus of both communities and we encourage everybody to get involved. Hosting this conference in Kigali is like a shot in the arm that can only lead us on to even bigger and brighter things.”

Sir Peter Gluckman, President of the International Science Council, and founding chair of INGSA mentioned: “Good science advice is critical to decision making at any level from local to global. It helps decision makers understand the evidence for or against, and the implications of any choice they make. In that way science advice makes it more likely that decision makers will make better decisions. INGSA as the global capacity building platform has a critical role to play in ensuring the quality of science policy interface.”

Strength in numbers

What makes the 5th edition of this biennial event stand out is the perhaps the novel range of speakers from all continents working at the boundary between science, society and policy willing to make their voices heard. More information on Parallel Sessions organisers as well as speakers can be found on the website.

About INGSA

Founded in 2014 with regional chapters in Africa, Asia and Latin America and the Caribbean, and key partnerships in Europe and North America, INGSA has quicky established an important reputation as a collaborative platform for policy exchange, capacity building and operational research across diverse global science advisory organisations and national systems. INGSA is a free community of peer support and practice with over 6,000 members globally. Science communicators and members of the media are warmly welcomed to join for free.

Through workshops, conferences and a growing catalogue of tools and guidance, the network aims to enhance the global science-policy interface to improve the potential for evidence-informed policy formation at sub-national, national and transnational levels. INGSA operates as an affiliated body of the International Science Council. INGSA’s secretariat is based at the University of Auckland in New Zealand, while the office of the President is hosted at the Fonds de Recherche de Quebec in Montreal, which has also launched the Réseau francophone international en conseil scientifique (RFICS), which mandate is towards capacity reinforcement in science advice in the Francophonie.

INGSA2024 Sponsors

As always, INGSA organized a highly accessible and inclusive conference by not charging a registration fee. Philanthropic support from many sponsors made the conference possible. Special recognition is made to the Fonds de recherche du Québec, the Rwanda Ministry of Education as well as the University of Rwanda. The full list of donors is available on the INGSA2024 website (link below).

[1] Australia, Belgium, Brazil, Cameroon, Canada, Chile, China, Costa Rica, Cote d’Ivoire, Denmark, Egypt, Ethiopia, Finland, France, Germany, Ghana, India, Ireland, Italy, Jamaica, Japan, Kenya, Lebanon, Malawi, Malaysia, Mauritius, Mexico, New Zealand, Nigeria, Portugal, Rwanda, Saudi Arabia, South Africa, Spain, Sri Lanka, Uganda, UK, USA, Zimbabwe

Satellite session are taking place today (May 3, 2024),

  • High-Level Dialogue on the Future of Science
  • Bridging Worlds of Knowledge
  • Translating Research into Policy and Practice
  • Quantum Technology in Africa

The last session on the list, “Quantum Technology …,” is a science diplomacy role-playing workshop. (It’s of particular interest to me as the Council of Canadian Academies (CCA) released a report, Quantum Potential, in Fall 2023 and about which I’m still hoping to write a commentary.)

Even though the sessions have already taken place,it’s worth taking a look at the conference programme and the satellite events just to get a sense of the global breadth of interest in this work. Here’s the INGSA2024 website.

Latest Canadian students’ math and reading scores drop, the 2022 PISA (Programme for International Student Assessment]) scorecard

It took a while (until December 2023) for the OECD’s (Organization for Economic Cooperation Development) to release its latest (2022) PISA (Programme for International Student Assessment) scores.

Where Canada is concerned the scores seem to be a case of ‘the same old same old as per my October 9, 2013 posting about Canada’s then latest PISA scores, “What happened? 2009 report says Canadian students are leaders in reading, math, and science; 2013 report says Canadian students are dropping out of maths and sciences.”

Onto the 2022 results: you can find the OECD’s November 5, 2023 press release, “Decline in educational performance only partly attributable to the COVID-19 pandemic,” announcing the latest PISA result and there’s this December 5, 2023 CBC (Canadian Broadcasting Corporation) online news item, which contrasts the 2022 results with the 2018 results, Note: A link has been removed,

Math and reading scores of Canadian students continue to decline steeply, matching a global trend, according to a new study.

The state of global education was given a bleak appraisal in the Program for International Student Assessment (PISA), which is the first study to examine the academic progress of 15-year-old students in dozens of countries during the pandemic.

Released Tuesday [December 5, 2023], it finds the average international math score fell by the equivalent of 15 points compared to 2018 scores, while reading scores fell 10 points.

The study found Canada’s overall math scores declined 15 points between 2018 and 2022. According to PISA, which defines a drop of 20 points as losing out on a fully year of learning, that means Canada’s math score dropped by an equivalent of three-quarters of a year of learning.

During that same time period, reading scores of Canadian students dropped by 13 points and science by three.

Only 12 per cent of Canadian students were high math achievers, scoring at Level 5 or 6. That’s fewer than some of the top Asian countries and economies: In Singapore, 41 per cent of students performed at the top level; in Hong Kong, 27 per cent; and in Japan and Korea, 23 per cent.

Louis Volante, a professor of education governance at Brock University in St. Catharines, Ont., believes the pandemic had more of a negative effect on math learning than reading and science.

‘Some provinces declining more than others’

Anna Stokke, a math professor at the University of Winnipeg, notes that math scores in Canada have been trending in the wrong direction since 2003, “with some provinces declining more than others.”

According to the study, the provinces with the largest drop in math scores since 2018 were Newfoundland Labrador with 29, Nova Scotia with 24, New Brunswick with 23 and Manitoba with 22. Meanwhile, Alberta’s score only dropped by seven and B.C.’s just eight.

“I do think part of the problem is the philosophy of how to teach math,” Stokke told CBC News.

“First of all, we’re not spending enough time on math in schools. And second of all, kids just aren’t getting good instruction in a lot of cases. They’re not getting explicit instruction. They’re not getting enough practice. And that really needs to change.”

A survey of students found about half faced closures of more than three months, but it didn’t always lead to lower scores. There was “no clear difference” in performance trends between countries that had limited closures, including Iceland and Sweden, and those with longer closures, including Brazil and Ireland, according to the report.

Canada still in top 10

Singapore, long seen as an education powerhouse, had the highest scores by far in every subject. It was joined in the upper echelons by other East Asian countries, including Japan and China.

Despite the declines across the subjects, Canada did well compared to the other countries in the report, placing ninth in math, sixth in reading and seventh in science.

Usually given every three years, the latest test was delayed a year because of the pandemic. It was administered in 2022 to a sample of 15-year-olds in 37 countries that are OECD members, plus 44 other partner countries. The test has been conducted since 2000.

In 2022, 81 countries participated, with 23,000 Canadian high school students writing the test.

If you don’t have time to read all of the December 5, 2023 CBC online news item, there’s Quinn Henderson’s succinct December 6, 2023 article for the Daily Hive,

Wendy Hughes (then PhD student) and Sarfaroz Niyozov (then associate professor) both associated with the University of Toronto, presented a critique of PISA in their June 4, 2019 essay on The Conversation,

The Program for International Student Assessment (PISA) — the Organization for Economic Co-operation and Development’s (OECD) global standardized test of student achievement — is frequently used by commentators to compare and rank national or provincial education systems.

PISA, which has now spread into 80 countries as a best education practice, presents itself as a tool to help countries make their systems more inclusive leading to equitable outcomes. But PISA is far more ambiguous and controversial.

Many academics and educators critique PISA as an economic measurement, not an educational one. The media generally use PISA results to blame and shame school systems. And the way that some politicians, policy-makers and researchers have used PISA is more closely aligned to a political process than an educational one.

You can find the PISA 2022 results here.

Innovative nanovector (nanogel) could pave way for new spinal cord injury treatments

Caption: Nanogel – Scheme of selective drug treatment in the central nervous system. Credit Politecnico di Milano – Istituto Mario Negri

A February 14, 2024 news item on Nanowerk provides some context for the image in the above, Note: A link has been removed,

In a study published in Advanced Materials (“Synergistic Pharmacological Therapy to Modulate Glial Cells in Spinal Cord Injury”), researchers Pietro Veglianese, Valeria Veneruso and Emilia Petillo from Istituto di Ricerche Farmacologiche Mario Negri IRCCS in collaboration with Filippo Rossi of the Politecnico di Milano have demonstrated that an innovative nanovector (nanogel), which they developed, is able to deliver anti-inflammatory drugs in a targeted manner into glial cells actively involved in the evolution of spinal cord injury, a condition that leads to paraplegia or quadriplegia [also known as tetraplegia].

A February 20, 2024 Politecnico di Milano press release (also on EurekAlert but published February 14, 2024) which originated the news item, provides a bit more information about the difficulties with current treatments and the advantages of the new approach,

Treatments currently available to modulate the inflammatory response mediated by the component that controls the brain’s internal environment after acute spinal cord injury showed limited efficacy. This is also due to the lack of a therapeutic approach that can selectively act on microglial and astrocytic cells.

The nanovectors developed by Politecnico di Milano, called nanogels, consist of polymers that can bind to specific target molecules. In this case, the nanogels were designed to bind to glial cells, which are crucial in the inflammatory response following acute spinal cord injury. The collaboration between Istituto di Ricerche Farmacologiche Mario Negri IRCCS and Politecnico di Milano showed that nanogels, loaded with a drug with anti-inflammatory action (rolipram), were able to convert glial cells from a damaging to a protective state, actively contributing to the recovery of injured tissue. Nanogels showed to have a selective effect on glial cells, releasing the drug in a targeted manner, maximising its effect and reducing possible side effects.

“The key to the research was understanding the functional groups that can selectively target nanogels within specific cell populations”, explains Filippo Rossi, professor at the Department of Chemistry, Materials and Chemical Engineering ‘Giulio Natta’ at Politecnico di Milano – This makes it possible to optimise drug treatments by reducing unwanted effects”.

“The results of the study”, continues Pietro Veglianese, Head of the Acute Spinal Trauma and Regeneration Unit, Department of Neuroscience at Istituto Mario Negri, “show that nanogels reduced inflammation and improved recovery capacity in animal models with spinal cord injury, partially restoring motor function. These results open the way to new therapeutic possibilities for myelolysis patients. Moreover, this approach may also be beneficial for treating neurodegenerative diseases such as Alzheimer’s, in which inflammation and glial cells play a significant role”.

Here’s a link to and a citation for the paper,

Synergistic Pharmacological Therapy to Modulate Glial Cells in Spinal Cord Injury by Valeria Veneruso, Emilia Petillo, Fabio Pizzetti, Alessandro Orro, Davide Comolli, Massimiliano De Paola, Antonietta Verrillo, Arianna Baggiolini, Simona Votano, Franca Castiglione, Mattia Sponchioni, Gianluigi Forloni, Filippo Rossi, Pietro Veglianese. Advanced Materials Volume 36, Issue 3 January 18, 2024 2307747 DOOI: https://doi.org/10.1002/adma.202307747 First published: 22 November 2023

This paper is open access.

A graphene joke (of sorts): What did the electron ‘say’ to the phonon in the graphene sandwich?

Unfortunately, there isn’t a punch line but I appreciate the effort to inject a little lightness into the description of a fairly technical achievement, from a February 12, 2024 news item on Nanowerk, Note: A link has been removed,

Electrons carry electrical energy, while vibrational energy is carried by phonons. Understanding how they interact with each other in certain materials, like in a sandwich of two graphene layers, will have implications for future optoelectronic devices.

Key Takeaways

Twisted graphene layers exhibit unique electrical properties.

Electron-phonon interactions crucial for energy loss in graphene.

Discovery of a new physical process involving electron-phonon Umklapp scattering.

Potential implications for ultrafast optoelectronics and quantum applications.

A February 9, 2024 Eindhoven University of Technology (TU/e; Netherlands) press release, which originated the news item, is reproduced here in its entirety, Note: Links have been removed,

Electrons carry electrical energy, while vibrational energy is carried by phonons. Understanding how they interact with each other in certain materials, like in a sandwich of two graphene layers, will have implications for future optoelectronic devices. Recent work has revealed that graphene layers twisted relative to each other by a small ‘magic angle’ can act as perfect insulator or superconductor. But the physics of the electron-phonon interactions are a mystery. As part of a worldwide international collaboration, TU/e researcher Klaas-Jan Tielrooij has led a study on electron-phonon interactions in graphene layers. And they have made a startling discovery.

What did the electron say to the phonon between two layers of graphene?

This might sound like the start of a physics meme with a hilarious punchline to follow. But that’s not the case according to Klaas-Jan Tielrooij. He’s an associate professor at the Department of Applied Physics and Science Education at TU/e and the research lead of the new work published in Science Advances.

“We sought to understand how electrons and phonons ‘talk’ to each other within two twisted graphene layers,” says Tielrooij.

Electrons are the well-known charge and energy carriers associated with electricity, while a phonon is linked to the emergence of vibrations between atoms in an atomic crystal.

“Phonons aren’t particles like electrons though, they’re a quasiparticle. Yet, their interaction with electrons in certain materials and how they affect energy loss in electrons has been a mystery for some time,” notes Tielrooij.

But why would it be interesting to learn more about electron-phonon interactions? “These interactions can have a major effect on the electronic and optoelectronic properties of devices, made from materials like graphene, which we are going to see more of in the future.”

Twistronics: Breakthrough of the Year 2018

Tielrooij and his collaborators, who are based around the world in Spain, Germany, Japan, and the US, decided to study electron-phonon interactions in a very particular case – within two layers of graphene where the layers are ever-so-slightly misaligned.

Graphene is a two-dimensional layer of carbon atoms arranged in a honeycomb lattice that has several impressive properties such as high electrical conductivity, high flexibility, and high thermal conductivity, and it is also nearly transparent.

Back in 2018, the Physics World Breakthrough of the Year award went to Pablo Jarillo-Herrero and colleagues at MIT [Massachusetts Institute of Technology] for their pioneering work on twistronics, where adjacent layers of graphene are rotated very slightly relative to each other to change the electronic properties of the graphene.

Twist and astound!

“Depending on how the layers of graphene are rotated and doped with electrons, contrasting outcomes are possible. For certain dopings, the layers act as an insulator, which prevents the movement of electrons. For other doping, the material behaves as a superconductor – a material with zero resistance that allows the dissipation-less movement of electrons,” says Tielrooij.

Better known as twisted bilayer graphene, these outcomes occur at the so-called magic angle of misalignment, which is just over one degree of rotation. “The misalignment between the layers is tiny, but the possibility for a superconductor or an insulator is an astounding result.”

How electrons lose energy

For their study, Tielrooij and the team wanted to learn more about how electrons lose energy in magic-angle twisted bilayer graphene, or MATBG for short.

To achieve this, they used a material consisting of two sheets of monolayer graphene (each 0.3 nanometers thick), placed on top of each other, and misaligned relative to each other by about one degree.

Then using two optoelectronic measurement techniques, the researchers were able to probe the electron-phonon interactions in detail, and they made some staggering discoveries.

“We observed that the energy vanishes very quickly in the MATBG – it occurs on the picosecond timescale, which is one-millionth of one-millionth of a second!” says Tielrooij.

This observation is much faster than for the case of a single layer of graphene, especially at ultracold temperatures (specifically below -73 degrees Celsius). “At these temperatures, it’s very difficult for electrons to lose energy to phonons, yet it happens in the MATBG.”

Why electrons lose energy

So, why are the electrons losing the energy so quickly through interaction with the phonons? Well, it turns out the researchers have uncovered a whole new physical process.

“The strong electron-phonon interaction is a completely new physical process and involves so-called electron-phonon Umklapp scattering,” adds Hiroaki Ishizuka from Tokyo Institute of Technology in Japan, who developed the theoretical understanding of this process together with Leonid Levitov from Massachusetts Institute of Technology in the US.

Umklapp scattering between phonons is a process that often affects heat transfer in materials, because it enables relatively large amounts of momentum to be transferred between phonons.

“We see the effects of phonon-phonon Umklapp scattering all the time as it affects the ability for (non-metallic) materials at room temperature to conduct heat. Just think of an insulating material on the handle of a pot for example,” says Ishizuka. “However, electron-phonon Umklapp scattering is rare. Here though we have observed for the first time how electrons and phonons interact via Umklapp scattering to dissipate electron energy.”

Challenges solved together

Tielrooij and collaborators may have completed most of the work while he was based in Spain at the Catalan Institute of Nanoscience and Nanotechnology (ICN2), but as Tielrooij notes. “The international collaboration proved pivotal to making this discovery.”

So, how did all the collaborators contribute to the research? Tielrooij: “First, we needed advanced fabrication techniques to make the MATBG samples. But we also needed a deep theoretical understanding of what’s happening in the samples. Added to that, ultrafast optoelectronic measurement setups were required to measure what’s happening in the samples too.”

Tielrooij and the team received the magic-angle twisted samples from Dmitri Efetov’s group at Ludwig-Maximilians-Universität in Munich, who were the first group in Europe able to make such samples and who also performed photomixing measurements, while theoretical work at MIT in the US and at Tokyo Institute of Technology in Japan proved crucial to the success of the research.

At ICN2, Tielrooij and his team members Jake Mehew and Alexander Block used cutting-edge equipment particularly time-resolved photovoltage microscopy to perform their measurements of electron-phonon dynamics in the samples.

The future

So, what does the future look like for these materials then? According to Tielrooij, don’t expect anything too soon.

“As the material is only being studied for a few years, we’re still some way from seeing magic-angle twisted bilayer graphene having an impact on society.”

But there is a great deal to be explored about energy loss in the material.

“Future discoveries could have implications for charge transport dynamics, which could have implications for future ultrafast optoelectronics devices,” says Tielrooij. “In particular, they would be very useful at low temperatures, so that makes the material suitable for space and quantum applications.”

The research from Tielrooij and the international team is a real breakthrough when it comes to how electrons and phonons interact with each other.

But we’ll have to wait a little longer to fully understand the consequences of what the electron said to the phonon in the graphene sandwich.

Illustration showing the control of energy relaxation with twist angle. Image: Authors

Here’s a link to and a citation for the paper,

Ultrafast Umklapp-assisted electron-phonon cooling in magic-angle twisted bilayer graphene by Jake Dudley Mehew, Rafael Luque Merino, Hiroaki Ishizuka, Alexander Block, Jaime Díez Mérida, Andrés Díez Carlón, Kenji Watanabe, Takashi Taniguchi, Leonid S. Levitov, Dmitri K. Efetov, and Klaas-Jan Tielrooij. Science Advances 9 Feb 2024 Vol 10, Issue 6 DOI: 10.1126/sciadv.adj1361

This paper is open access.