ETH Zurich research articles from Innovation Toronto
- Thermometer 100 times as sensitive – April 12, 2015
- Bioplastic – greener than ever – December 29, 2014
- Controlling genes with your thoughts – November 13, 2014
- Controlling genes with your thoughts – November 11, 2014
- Precise and programmable biological circuits – October 24, 2014
- Smartphone understands gestures – October 11, 2014
- Where humans, animals and robots meet – October 1, 2014
- Atomically thin material opens door for integrated nanophotonic circuits – September 7, 2014
- Nanoscale assembly line – August 30, 2014
- C2D2 fighting corrosion – August 23, 2014
- Why global warming is taking a break – August 20, 2014
- Curing arthritis in mice – August 7, 2014
- New approach for tuberculosis drugs – July 6, 2014
- A Shape-Conscious Alloy: New materials for the building industry – June 22, 2014
- Producing hydrogen with sunlight: Collecting light with artificial moth eyes – June 19, 2014
- Joint implants without an expiry date – June 5, 2014
- Think fast, robot – June 1, 2014
- SOLAR-JET: Fuel directly from sunlight, water and carbon dioxide – potentially a fuel revolution – May 4, 2014
- Thinnest feasible membrane produced – nano-membrane made out of the “super material” graphene – April 19, 2014
- “Electronic Skin” Equipped with Memory
- Never say never in the nano-world | Surprises at the nanoscale
- Synthetic natural gas from excess electricity
- Ultra-thin and transparent sensors and circuits
- Cube-shaped robot balances on one corner and can move on its own | Cubli
- Scientists Warn That Warming ‘Will be Hard to Reverse’ | plans to limit climate change
- Could a cybernetic implant really help you lose weight?
- Penguin-inspired propulsion system
- World Record: Wireless Data Transmission at 100 Gb/s
- The room with 260 million surfaces: 3D printed architecture is here
- Niacin, the fountain of youth
- Chasing the black holes of the ocean
- The efficient choice among combustion engines
- Teleported by electronic circuit
- Chips that mimic the brain
- Watch: Autonomous Robots Self-Assemble and Take Flight as One
- First global atlas of marine plankton reveals remarkable underwater world
- Global Networks Must be Re-Designed
- High Concentration PhotoVoltaic Thermal: Harness the Energy of 2,000 Suns
- Study Led by NUS Scientists Reveals Escalating Cost of Forest Conservation
- Germanium made compatible – faster communications on the way
- Tin nanocrystals for the battery of the future
- Exhaled breath is unique fingerprint
- Web-based ‘brain’ for robots goes live
- Naro Nautical Robot
- Sweating rooftops could save 60% on air conditioning
- Flying robots cooperate to play catch
- Koubachi takes its Wi-Fi Plant Sensor to the great outdoors
- Swiss Flying Torpedo Bot Crashes, Dusts Itself Off and Flies Again
- New plaster enhances wound healing
- Swiss researchers present breakthrough in semiconductor structuring
- Biological ‘Computer’ Destroys Cancer Cells
- Biomarker research could lead to finger-prick cancer test
- Self-regulating traffic lights would improve vehicle flow
- Nanotech Breath Sensor Detects Diabetes and Potentially Serious Complication
- Predicting Economic Crises With ‘Econophysics’
- World’s Smallest Microlaser Could Revolutionize Chip Technology
- 3-D Microchips for More Powerful and Environmentally Friendly Computers
- Fuelling fears
- Neuroelectronics Make Smarter Computer Chips
- Newcastle University research shows how dogs could help the elderly
- Psychotherapy via internet as good as if not better than face-to-face consultations
- Roboy, the ambassador of a new generation of intelligent machines, is brought to life
- Disney develops “face cloning” technique for animatronics
- Computer scientists create 3D models using millions of 2D images
- Single molecule’s stunning image
- Internet uses hot water to lower its cooling bills
- Tiny chip could diagnose disease
Like its sister institution Swiss Federal Institute of Technology in Lausanne (EPFL), it is an integral part of the Swiss Federal Institutes of Technology Domain (ETH Domain) that is directly subordinate to Switzerland’s Federal Department of Economic Affairs, Education and Research.
ETH Zürich is consistently ranked by all major World University rankings among the top universities in the world. It is considered the best university in continental Europe by the Shanghai Ranking ARWU, the Times Higher Education World University Rankings Ranking and the QS World University Ranking. It is currently ranked 8th best university in the world in engineering, science and technology and 2nd in Europe after the University of Cambridge. Twenty-one Nobel Prizes have been awarded to students or professors of the Institute in the past, the most famous of which is Albert Einstein in 1921, and the most recent is Kurt Wüthrich in 2002. It is a founding member of the IDEA League and the International Alliance of Research Universities (IARU) and a member of the CESAER network.
Scientists have developed a highly sensitive sensor to detect tiny changes in strong magnetic fields. The sensor may find widespread use in medicine and other areas.
Researchers from the Institute for Biomedical Engineering, which is operated jointly by ETH Zurich and the University of Zurich, have succeeded in measuring tiny changes in strong magnetic fields with unprecedented precision. In their experiments, the scientists magnetised a water droplet inside a magnetic resonance imaging (MRI) scanner, a device that is used for medical imaging. The researchers were able to detect even the tiniest variations of the magnetic field strength within the droplet. These changes were up to a trillion times smaller than the seven tesla field strength of the MRI scanner used in the experiment.
“Until now, it was possible only to measure such small variations in weak magnetic fields,” says Klaas Prüssmann, Professor of Bioimaging at ETH Zurich and the University of Zurich. An example of a weak magnetic field is that of the Earth, where the field strength is just a few dozen microtesla. For fields of this kind, highly sensitive measurement methods are already able to detect variations of about a trillionth of the field strength, says Prüssmann. “Now, we have a similarly sensitive method for strong fields of more than one tesla, such as those used, inter alia, in medical imaging.”
Newly developed sensor
The scientists based the sensing technique on the principle of nuclear magnetic resonance, which also serves as the basis for magnetic resonance imaging and the spectroscopic methods that biologists use to elucidate the 3D structure of molecules.
However, to measure the variations, the scientists had to build a new high-precision sensor, part of which is a highly sensitive digital radio receiver. “This allowed us to reduce background noise to an extremely low level during the measurements,” says Simon Gross. Gross wrote his doctoral thesis on this topic in Prüssmann’s group and is lead author of the paper published in the journal Nature Communications.
Eliminating antenna interference
In the case of nuclear magnetic resonance, radio waves are used to excite atomic nuclei in a magnetic field. This causes the nuclei to emit weak radio waves of their own, which are measured using a radio antenna; their exact frequency indicates the strength of the magnetic field.
As the scientists emphasise, it was a challenge to construct the sensor in such a way that the radio antenna did not distort the measurements. The scientists have to position it in the immediate vicinity of the water droplet, but as it is made of copper it becomes magnetised in the strong magnetic field, causing a change in the magnetic field inside the droplet.
The researchers therefore came up with a trick: they cast the droplet and antenna in a specially prepared polymer; its magnetisability (magnetic susceptibility) exactly matched that of the copper antenna. In this way, the scientists were able to eliminate the detrimental influence of the antenna on the water sample.
Broad applications expected
This measurement technique for very small changes in magnetic fields allows the scientists to now look into the causes of such changes. They expect their technique to find use in various areas of science, some of them in the field of medicine, although the majority of these applications are still in their infancy.
“In an MRI scanner, the molecules in body tissue receive minimal magnetisation – in particular, the water molecules that are also present in blood,” explains doctoral student Gross. “The new sensor is so sensitive that we can use it to measure mechanical processes in the body; for example, the contraction of the heart with the heartbeat.”
The scientists carried out an experiment in which they positioned their sensor in front of the chest of a volunteer test subject inside an MRI scanner. They were able to detect periodic changes in the magnetic field, which pulsated in time with the heartbeat. The measurement curve is reminiscent of an electrocardiogram (ECG), but unlike the latter measures a mechanical process (the contraction of the heart) rather than electrical conduction. “We are in the process of analysing and refining our magnetometer measurement technique in collaboration with cardiologists and signal processing experts,” says Prüssmann. “Ultimately, we hope that our sensor will be able to provide information on heart disease – and do so non-invasively and in real time.”
Development of better contrast agents
The new measurement technique could also be used in the development of new contrast agents for magnetic resonance imaging: in MRI, the image contrast is based largely on how quickly a magnetised nuclear spin reverts to its equilibrium state. Experts call this process relaxation. Contrast agents influence the relaxation characteristics of nuclear spins even at low concentrations and are used to highlight certain structures in the body.
In strong magnetic fields, sensitivity issues had previously restricted scientists to measurement of just two of the three spatial nuclear spin components and their relaxation. They had to rely on an indirect measurement of relaxation in the important third dimension. For the first time, the new high-precision measurement technique allows the direct measurement of all three dimensions of nuclear spin in strong magnetic fields.
Direct measurement of all three nuclear spin components also paves the way for future developments in nuclear magnetic resonance (NMR) spectroscopy for applications in biological and chemical research.
Researchers from the Graphene Flagship use layered materials to create an all-electrical quantum light emitting diodes (LED) with single-photon emission. These LEDs have potential as on-chip photon sources in quantum information applications.
Atomically thin LEDs emitting one photon at a time have been developed by researchers from the Graphene Flagship. Constructed of layers of atomically thin materials, including transition metal dichalcogenides (TMDs), graphene, and boron nitride, the ultra-thin LEDs showing all-electrical single photon generation could be excellent on-chip quantum light sources for a wide range of photonics applications for quantum communications and networks. The research, reported in Nature Communications, was led by the University of Cambridge, UK.
The ultra-thin devices reported in the paper are constructed of thin layers of different layered materials, stacked together to form a heterostructure. Electrical current is injected into the device, tunnelling from single-layer graphene, through few-layer boron nitride acting as a tunnel barrier, and into the mono- or bi-layer TMD material, such as tungsten diselenide (WSe2), where electrons recombine with holes to emit single photons. At high currents, this recombination occurs across the whole surface of the device, while at low currents, the quantum behaviour is apparent and the recombination is concentrated in highly localised quantum emitters.
All-electrical single photon emission is a key priority for integrated quantum optoelectronics. Typically, single photon generation relies on optical excitation and requires large-scale optical set-ups with lasers and precise alignment of optical components. This research brings on-chip single photon emission for quantum communication a step closer. Professor Mete Atatüre (Cavendish Laboratory, University of Cambridge, UK), co-author of the research, explains “Ultimately, in a scalable circuit, we need fully integrated devices that we can control by electrical impulses, instead of a laser that focuses on different segments of an integrated circuit. For quantum communication with single photons, and quantum networks between different nodes – for example, to couple qubits – we want to be able to just drive current, and get light out. There are many emitters that are optically excitable, but only a handful are electrically driven” In their devices, a modest current of less than 1 µA ensures that the single-photon behaviour dominates the emission characteristics.
The layered structure of TMDs makes them ideal for use in ultra-thin heterostructures for use on chips, and also adds the benefit of atomically precise layer interfacing. The quantum emitters are highly localised in the TMD layer and have spectrally sharp emission spectra. The layered nature also offers an advantage over some other single-photon emitters for feasible and effective integration into nanophotonic circuits. Professor Frank Koppens (ICFO, Spain), leader of Work Package 8 – Optoelectronics and Photonics, adds “Electrically driven single photon sources are essential for many applications, and this first realisation with layered materials is a real milestone. This ultra-thin and flexible platform offers high levels of tunability, design freedom, and integration capabilities with nano-electronic platforms including silicon CMOS.”
This research is a fantastic example of the possibilities that can be opened up with new discoveries about materials. Quantum dots were discovered to exist in layered TMDs only very recently, with research published simultaneously in early 2015 by several different research groups including groups currently working within the Graphene Flagship. Dr Marek Potemski and co-workers working at CNRS (France) in collaboration with researchers at the University of Warsaw (Poland) discovered stable quantum emitters at the edges of WSe2 monolayers, displaying highly localised photoluminescence with single-photon emission characteristics. Professor Kis and colleagues working at ETH Zurich and EPFL (Switzerland) also observed single photon emitters with narrow linewidths in WSe2. At the same time, Professor van der Zant and colleagues from Delft University of Technology (Netherlands), working with researchers at the University of Münster (Germany) observed that the localised emitters in WSe2 are due to trapped excitons, and suggested that they originate from structural defects. These quantum emitters have the potential to supplant research into the more traditional quantum dot counterparts because of their numerous benefits of the ultrathin devices of the layered structures.
With this research, quantum emitters are now seen in another TMD material, namely tungsten disulphide (WS2). Professor Atatüre says “We chose WS2 because it has higher bandgap, and we wanted to see if different materials offered different parts of the spectra for single photon emission. With this, we have shown that the quantum emission is not a unique feature of WSe2, which suggests that many other layered materials might be able to host quantum dot-like features as well.”
ETH researchers are developing tiny, sophisticated technological and biological machines enabling non-invasive, selective therapies. Their creations include genetically modified cells that can be activated via brain waves, and swarms of microrobots that facilitate highly precise application of drugs.
Richard Fleischner, who directed the 1966 cult film Fantastic Voyage, would have been delighted with Bradley Nelson’s research: similar to the story in Fleischner’s film, Nelson wants to load tiny robots with drugs and manoeuvre them to the precise location in the human body where treatment is needed, for instance to the site of a cancer tumour. Alternatively, the tiny creatures could also be fitted with instruments, allowing operations to be performed without surgical intervention. The advantages compared with conventional treatments with drugs are clear: far more targeted therapy, and as a result, fewer side effects.
Fine-tuning materials and designs
Nelson isn’t a dreamer or a storyteller – he is Professor of Robotics and Intelligent Systems at ETH Zurich, and he has an international reputation for his micro- and nanorobots. He still holds the Guinness World Record for the “most advanced mini robot for medical use”. His robots are typically just a few micrometres in size and are inspired by nature. He derives models for his own micrometre-scale mechanical propul- sion systems by observing microorganisms and seeing, for example, how the flagellum – a sort of curly tail that aids in movement – works in bacteria. The robots get the energy to move from an external impulse, such as an electromagnetic field.
Although this vision seems to be science fiction, Nelson’s group is gradually making it a reality: in an in vivo experiment, they were able to accurately guide a swarm of 80,000 microrobots within a mouse to demonstrate the delivery of a model drug to targeted locations. Nevertheless, the researchers still have to resolve a number of questions before they can address the first set of applications in humans. The questions focus on materials and design: “When designing robots like this, we can’t rely on our intuition because, on this small a scale, materials often behave differently than we are used to,” explains Nelson. Special 3D printers have expanded the range of materials used in microrobot design, going beyond semiconductor metals to include polymers. As a result, last year Nelson’s team in collaboration with Professor Christofer Hierold’s team was able to create a robot from a biocompatible biopolymer that dissolves in the body after completing its task.
In his latest publication, Nelson goes one step further. The microrobots presented there can transform their shape depending on the environmental conditions, which is why Nelson calls them “origami robots”. The change in shape can be stimulated by a change in the pH of body fluids, a temperature difference or a light pulse. The robots’ plasticity is based on a multilayer structure with different hydrogels. Since the biopolymers expand or contract differently under external stimuli, the robot is able to change shape.
Again, nature provided the model for the design: the Trypanosoma bruceibacterium, the pathogen responsible for sleeping sickness, has a narrow, elongated shape to help it move efficiently in body fluids. However, as soon as the bacterium is in the bloodstream and no longer has to propel itself, it transitions to a stubby, compact shape – a further design option for a maximum-efficiency medical microrobot.
“Fifteen years ago we were just getting started, but today we are already able to control many different mechanisms very precisely,” says Nelson. The next big challenge is autonomy: “We’re examining how we can make the microrobots intelligent,” he says. Specifically, once they have been released in the body, the researchers want the tiny devices to find the targets on their own – just as natural single-celled organisms have been doing for millions of years.
Cells as biological surveillance systems
Nelson isn’t the only ETH researcher who is fundamentally rethinking medicine: Martin Fussenegger, Professor of Biotechnology and Bioengineering, is planning a minor revolution in medical therapy. He thinks it’s “outrageous” that we simply pump drugs into our bodies, usually relatively late in the course of the illness, and then hope for the desired effect.
That’s why his team in the Department of Biosystems Science and Engineering (D-BSSE) in Basel is pursuing a different route, intended to get the treatment to the core of the illness. “We reprogram the body’s cells to be biological surveillance systems. In the body, they respond quickly to illnesses,” says Fussenegger. These “molecular prosthetics” will be aimed at compensating metabolic defects that are responsible for such illnesses as diabetes, cancer and obesity.
Using standard molecular methods, Fussenegger can reprogram cells in such a way that an external impulse causes them to produce and excrete a desired active substance – usually certain proteins. His team uses light as the impulse; although the field of optogenetics is still quite young, it has made great progress in recent years in systematically controlling genetically modified cells using light. Two years ago Fussenegger succeeded for the first time, in the mouse model, in stimulating modified human cells to release a model human protein through irradiation with light in the near-infrared range.
Using implants to produce drugs
To allow the most precise control possible, Fussenegger’s group developed a synthetic implant that combines the light source (a tiny infrared LED) and a semipermeable culture chamber with the genetically modified cells. The lamp is then powered inductively by an external electromagnetic field. This sophisticated system paves the way for mind-directed therapies, for instance by means of an electroencephalogram recorded on the patient’s forehead. Fussenegger is certain that “such optogenetic therapy systems will be an important component of personalised medicine.” The implant tested in the mouse model was the size of a 2-Swiss-franc coin. The next generation will be more along the lines of a matchstick and will require significantly less energy.
“In future, the electricity for activating the lamp – and thus the protein production – could also come from a smartphone or a watch,” predicts Fussenegger. This would open up completely new possibilities for the doctor patient relationship: a doctor in the US could control the insulin level of a diabetes patient who is currently traveling in Europe by activating the production of the designer cells over the internet. At least, that’s one vision of medicine in the coming age of the internet of things.
Learn more: The microdoctors in our bodies
Researchers have created an interactive web tool to estimate the amount of energy that could be generated by wind or solar farms at any location.
The tool, called Renewables.ninja, aims to make the task of predicting renewable output easier for both academics and industry.
The creators, from Imperial College London and ETH Zürich, have already used it to estimate current Europe-wide solar and wind output, and companies such as the German electrical supplier RWE are using it to test their own models of output.
To test the model, Dr Iain Staffell, from the Centre for Environmental Policy at Imperial, and Dr Stefan Pfenninger, who is now at ETH Zürich, have used Renewables.ninja to estimate the productivity of all wind farms planned or under construction in Europe for the next 20 years. Their results are published today in the journal Energy.
We built our models so they can be easily used by other researchers online, allowing them to answer their questions faster, and hopefully to start asking new ones.
– Dr Iain Staffell
They found that wind farms in Europe current have an average ‘capacity factor’ of around 24 per cent, which means they produce around a quarter of the energy that they could if the wind blew solidly all day every day.
This number is a factor of how much wind is available to each turbine. The study found that because new farms are being built using taller turbines placed further out to sea, where wind speeds are higher, the average capacity factor for Europe should rise by nearly a third to around 31 percent.
This would allow three times as much energy to be produced by wind power in Europe compared to today, not only because there are more farms, but because those farms can take advantage of better wind conditions.
SUPER SUNNY DAYS
In another research paper also published today in Energy, the pair modelled the hourly output of solar panels across Europe. They found that even though Britain is not the sunniest country, on the best summer days solar power now produces more energy than nuclear power. However, the pattern of this solar output through the year substantially changes how the rest of the power system will have to operate.
Wind and solar energies have a strong dependence on weather conditions, and these can be difficult to integrate into national power systems that requires consistency. If there is excess power generated by all energy sources, then some supplies have to be turned off.
Currently, wind and solar power generators are the easiest to switch on and off, so they are often the first to go, meaning the power they generate can be wasted.
Making use of a larger capacity for solar energy generation relies on changes to the national energy system, such as adding new types of electricity storage or small and flexible generators to balance the variable output from solar panels.
MAKING MODELS FASTER
Renewables.ninja uses 30 years of observed and modelled weather data from organisations such as NASA to predict the wind speed likely to influence turbines and the sunlight likely to strike solar panels at any point on the Earth during the year.
Renewables.ninja has already allowed us to answer important questions about the current and future renewable energy infrastructure across Europe and in the UK, and we hope others will use it to further examine the opportunities and challenges for renewables in the future.
– Dr Stefan Pfenninger
These figures are combined with manufacturer’s specifications for wind turbines and solar panels to give an estimate of the power output that could be generated by a farm placed at any location.
Dr Staffell said he spent two years crunching the data for his own research and thought that creating this tool would make it quicker for others to answer important questions: “Modelling wind and solar power is very difficult because they depend on complex weather systems. Getting data, building a model and checking that it works well takes a lot of time and effort.
“If every researcher has to create their own model when they start to investigate a question about renewable energy, a lot of time is wasted. So we built our models so they can be easily used by other researchers online, allowing them to answer their questions faster, and hopefully to start asking new ones.”
He and Dr Pfenninger have been beta testing Renewables.ninja for six months and now have users from 54 institutions across 22 countries, including the European Commission and the International Energy Agency.
Dr Pfenninger said: “Renewables.ninja has already allowed us to answer important questions about the current and future renewable energy infrastructure across Europe and in the UK, and we hope others will use it to further examine the opportunities and challenges for renewables in the future.”
Scientists at the University of Basel, ETH Zurich, and NCCR Molecular Systems Engineering have developed an artificial metalloenzyme that catalyses a reaction inside of cells without equivalent in nature. This could be a prime example for creating new non-natural metabolic pathways inside living cells, as reported today in Nature.
The artificial metalloenzyme, termed biot-Ru–SAV, was created using the biotin–streptavidin technology. This method relies on the high affinity of the protein streptavidin for the vitamin biotin, where compounds bound to biotin can be introduced into the protein to generate artificial enzymes. In this study the authors introduced an organometallic compound, with the metal ruthenium at its base. Organometallic compounds are molecules containing at least one bond between a metal and a carbon atom, and are often used as catalysts in industrial chemical reactions. However, organometallic catalysts perform poorly, if at all, in aqueous solutions or cellular-like environments, and need to be incorporated into protein scaffolds like streptavidin to overcome these limitations.
“The goal was to create an artificial metalloenzyme that can catalyse olefin metathesis, a reaction mechanism that is not present among natural enzymes,” says Thomas R Ward, Professor at the Department of Chemistry, University of Basel, and senior author of the study. The olefin metathesis reaction is a method for the formation and redistribution of carbon-carbon double bonds widely used in laboratory research and large-scale industrial productions of various chemical products. Biot-Ru–SAV catalyses a ring-closing metathesis to produce a fluorescent molecule for easy detection and quantification.
Periplasm as reaction compartment
However, the environment inside a living cell is far from ideal for the proper functioning of organometallic-based enzymes. “The main breakthrough was the idea to use the periplasm of Escherichia coli as a reaction compartment, whose environment is much better suited for an olefin metathesis catalyst,” says Markus Jeschek, a researcher from the team of co-supervising author Sven Panke at the Department of Biosystems Science and Engineering, ETH Zurich in Basel. The periplasm, the space between the inner cytoplasmic membrane and the bacterial outer membrane in gram-negative bacteria, contains low concentrations of metalloenzymes inhibitors, such as glutathione.
Having found ideal in vivo conditions, the authors went a step forward and decided to optimize biot-Ru–SAV by applying principles of directed evolution, a method that mimics the process of natural selection to evolve proteins with enhanced properties or activities. “We could then develop a simple and robust screening method that allowed us to test thousands of biot-Ru–SAV mutants and identify the most active variant,” Ward explains.
Not only could the authors markedly improve the catalytic properties of biot-Ru–SAV, but they could also show that organometallic-based enzymes can be engineered and optimized for different substrates, thus producing a variety of different chemical products. “The exciting thing about this is that artificial metalloenzymes like biot-Ru–SAV can be used to produce novel high added-value chemicals,” Ward says. “It has a lot of potential to combine both chemical and biological tools to ultimately utilize cells as molecular factories.”
Learn more: Bringing artificial enzymes closer to nature
Researchers at Queen’s University Belfast and ETH Zurich, Switzerland, have created a new theoretical framework which could help physicists and device engineers design better optoelectronics, leading to less heat generation and power consumption in electronic devices which source, detect, and control light.
Speaking about the research, which enables scientists and engineers to quantify how transparent a 2D material is to an electrostatic field, Dr Elton Santos from the Atomistic Simulation Research Centre at Queen’s, said: “In our paper we have developed a theoretical framework that predicts and quantifies the degree of ‘transparency’ up to the limit of one-atom-thick, 2D materials, to an electrostatic field.
“Imagine we can change the transparency of a material just using an electric bias, e.g. get darker or brighter at will. What kind of implications would this have, for instance, in mobile phone technologies? This was the first question we asked ourselves. We realised that this would allow the microscopic control over the distribution of charged carriers in a bulk semiconductor (e.g. traditional Si microchips) in a nonlinear manner. This will help physicists and device engineers to design better quantum capacitors, an array of subatomic power storage components capable to keep high energy densities, for instance, in batteries, and vertical transistors, leading to next-generation optoelectronics with lower power consumption and dissipation of heat (cold devices), and better performance. In other words, smarter smart phones.”
Explaining how the theory could have important implications for future work in the area, Dr Santos added: “Our current model simply considers an interface formed between a layer of 2D material and a bulk semiconductor. In principle, our approach can be readily extended to a stack of multiple 2D materials, or namely, van der Waals heterostructures recently fabricated. This will allow us to design and predict the behaviour of these cutting-edge devices in prior to actual fabrication, which will significantly facilitate developments for a variety of applications. We will have an in silico search for the right combination of different 2D crystals while reducing the need for expensive lab work and test trials.”
Further information on the Atomistic Simulation Research Centre at Queen’s is available online at http://titus.phy.qub.ac.uk/
For the past few years, scientists around the world have been studying ways to use miniature robots to better treat a variety of diseases. The robots are designed to enter the human body, where they can deliver drugs at specific locations or perform precise operations like clearing clogged-up arteries. By replacing invasive, often complicated surgery, they could optimize medicine.
EPFL scientist Selman Sakar teamed up with Hen-Wei Huang and Bradley Nelson at ETHZ to develop a simple and versatile method for building such bio-inspired robots and equipping them with advanced features. They also created a platform for testing several robot designs and studying different modes of locomotion. Their work, published in Nature Communications, produced complex reconfigurable microrobots that can be manufactured with high throughput. They built an integrated manipulation platform that can remotely control the robots’ mobility with electromagnetic fields, and cause them to shape-shift using heat.
A robot that looks and moves like a bacterium
Unlike conventional robots, these microrobots are soft, flexible, and motor-less. They are made of a biocompatible hydrogel and magnetic nanoparticles. These nanoparticles have two functions. They give the microrobots their shape during the manufacturing process, and make them move and swim when an electromagnetic field is applied.
The sun is a clean and inexhaustible source of energy, with the potential to provide a sustainable answer to all future energy supply demands. There’s just one outstanding problem: the sun doesn’t always shine and its energy is hard to store. For the first time, researchers at the Paul Scherrer Institute PSI and the ETH Zurich have unveiled a chemical process that uses the sun’s thermal energy to convert carbon dioxide and water directly into high-energy fuels: a procedure developed on the basis of a new material combination of cerium oxide and rhodium. This discovery marks a significant step towards the chemical storage of solar energy.
The researchers published their findings in the research journal Energy and Environmental Science.
The sun’s energy is already being harnessed in various ways: whilst photovoltaic cells convert sun light into electricity, solar thermal installations use the vast thermal energy of the sun for purposes such as heating fluids to a high temperature. Solar thermal power plants involve the large-scale implementation of this second method: using thousands of mirrors, the sun light is focused on a boiler in which steam is produced either directly or via a heat exchanger at temperatures exceeding 500 °C. Turbines then convert thermal energy into electricity.
Researchers at the Paul Scherrer Institute PSI and the ETH Zurich have collaborated to develop a ground-breaking alternative to this approach. The new procedure uses the sun’s thermal energy to convert carbon dioxide and water directly into synthetic fuel.
Materials researchers at the Swiss Paul Scherrer Institute PSI in Villigen and the ETH Zurich have developed a very simple and cost-effective procedure for significantly enhancing the performance of conventional Li-ion rechargeable batteries. The procedure is scalable in size, so the use of rechargeable batteries will be optimized in all areas of application-whether in wristwatches, smartphones, laptops or cars. Battery storage capacity will be significantly extended, and charging times reduced.
The researchers reported on their results in the latest issue of the research journal Nature Energy.
It’s not necessary to re-invent the rechargeable battery in order to improve its performance. As Claire Villevieille, head of the battery materials research group at the Paul Scherrer Institute PSI says: “In the context of this competitive field, most researchers concentrate on the development of new materials.” In cooperation with colleagues at the ETH in Zurich, Villevieille and co-researcher Juliette Billaud took a different approach: “We checked existing components with a view to fully exploiting their potential.” Simply by optimizing the graphite anode – or negative electrode – on a conventional Li-ion battery, researchers were able to boost battery performance. “Under laboratory conditions, we were able to enhance storage capacity by a factor of up to 3. Owing to their complex construction, commercial batteries will not be able to fully replicate these results. But performance will definitely be enhanced, perhaps by as much as 30 – 50 percent: further experiments should yield more accurate prognoses.”
Researchers at Disney Research and ETH Zurich have demonstrated that consumer-grade light-emitting diode (LED) bulbs can, with some modifications, do double duty — both illuminating a room and providing a communications link for devices in that room.
This visible light communication (VLC) system would be suitable for connecting the many devices, such as appliances, wearable devices, sensors, toys and utilities, that could comprise the Internet of Things, or IoT, said Stefan Schmid, a Ph.D. student at Disney Research and ETH Zurich.
LEDs can both produce light and serve as light sensors. By having individual LEDs alternate between sending modulated light signals and serving as receivers of signals, it is possible to create a network of bulbs that can send messages to each other and connect to devices, while having no discernible effect on room lighting.
Schmid and his colleagues designed and implemented such a VLC system, demonstrating that it is a viable way to interconnect devices within a room.
Plant scientists at ETH Zurich have recently celebrated a world first at the ETH Zurich’s research station in Lindau-Eschikon: the launch of the ETH Field Phenotyping Platform (FIP), a unique crop phenotyping system. This gives researchers an incredibly accurate tool for measuring and monitoring the health and performance of field crops.
Driving towards the ETH Institute of Agricultural Sciences’ Research Station in Lindau-Eschikon, near Zurich, a series of tall masts immediately catches the eye and raises the question: what purpose could they possibly serve? Researchers from the Crop Science Group at ETH Zurich have now revealed their secret. On Friday 10th June, they held a small ceremony to launch a global first: an innovative crop phenotyping system that transfers sophisticated research capabilities from the lab to the field.
This new system will allow the scientists to study the crops in high detail virtually through the entire year. Their mission is to discover the differences between the individual plant varieties and to determine how long they need to flower, or to discover the exact link between their growth and the ambient temperature and soil moisture. The ETH researchers are currently studying hundreds of small plots of different varieties of wheat, soy, maize, buckwheat and forage grasses.
The monitoring system also allows the scientists to investigate whether – and how – fungal diseases develop on the crops, or to monitor weed cover on the ground. “In the long run, our system is a valuable tool for crop cultivation and precision farming”, summarises Achim Walter, Professor of Crop Science at ETH Zurich.