Science category

Smallest Satellite Ever Sent & Operated in Orbit By Breakthrough Starshot

Breakthrough Starshot is a research and engineering project by Breakthrough Initiatives to develop a proof-of-concept fleet of light sail spacecraft, named StarChip, capable of making the journey to the Alpha Centauri star system, 4.37 light-years away, at speeds between 15% and 20% of the speed of light, taking between 30 and 20 years to get there, respectively, and about 4 years to notify Earth of a successful arrival.

The project was announced on 12 April 2016 in an event in New York City by physicist and venture capitalist Yuri Milner and cosmologist Stephen Hawking who is serving as board member of the initiatives. Other board members include Facebook CEO Mark Zuckerberg. The project has an initial funding of US$100 million to start research. Milner places the final mission cost at $5–10 billion, and estimates the first craft could launch around 2036.

It is now in orbit!

On June 23, the initiative sent the tiniest-ever satellites into orbit. Thanks to an Indian rocket, 6 of these satellites, as named as Sprites, went to space. Some of them were attached to larger satellites: : the Latvian Venta satellite and the Italian Max Valier satellite which will release the other four Sprites to orbit once communications are achieved.

In fact, each Sprite contains a computer processor, solar panels, a magnetometer, a gyroscope, and a radio for communicating with researchers on Earth and all in a size of  3.5×3.5 cm circuit board.
Until now, only one signal came from on of the 2 Sprites. Since the Max Valier hasn’t established a connection yet, the remaining Sprites didn’t detach. Usually the satellite should receive a command to release its cargo, and this is not possible without a functioning antenna.
Despite the humble results, the team is feeling victorious. Having these small and cheap satellites hovering over the space and doing part of the job is an achievement.
These tiny satellites can go along on a planetary exploration mission and start deployment once they get there. By using these satellites, the risk of sending large spacecrafts will diminish.
 To find more details about the Breakthrough Starshot, check out this official website.

Bismuth Oxyiodide (BiOI)—A Non-toxic Alternative To Solar Cells

Bismuth is considered as a “green-element” and bismuth-based compounds are gaining attention as potentially non-toxic and defect-tolerant solar absorbers. The researchers of the University of Cambridge and the United States developed theoretical and experimental methods to show that bismuth, which sits next to lead (Pb) on the periodic table, can be used to make inexpensive solar cells.

Bismuth oxyiodide light absorbers
Bismuth oxyiodide light absorbers

The study suggests that solar cells including bismuth can have all the exceptional properties of lead-based solar cells but without any worries about toxicity. Another study by a different group discovered that bismuth-based solar cells have the ability to achieve a conversion efficiency of 22% which is comparable to the conversion efficiency of most advanced solar cell available in the market.

Many of the new materials recently investigated show limited photovoltaic performance. Bismuth Oxyiodide (BiOI) is one such compound and it is explored in detail through theory and experiment. Most of the solar cells commercially and domestically used are made from silicon (Si) which is efficient enough but has very low defect tolerance compared to bismuth oxyiodide. Low defect tolerance in silicon implies that the silicon needs to have very high levels of purity, making the production process energy-intensive.

Over the past several years researchers have been looking for an alternative to silicon for making solar cells cost effectively. The most promising group of these new materials are called hybrid lead halide perovskites. Unlike silicon, they don’t need such high purity levels. Hence, production is cheaper. But, the lead contained within perovskite solar cells represents a definite risk to all living beings and the environment. So, scientists are searching for non-toxic alternatives without compromising the performance.

Dr. Robert Hoye of Cambridge’s Cavendish Laboratory and Department of Materials Science & Metallurgy said,

We wanted to find out why defects don’t appear to affect the performance of lead-halide perovskite solar cells as much as they would in other materials.

The researchers are trying to figure out what’s special about the lead halide perovskites so that they can replicate their properties using non-toxic materials like bismuth.

Their research found that bismuth oxyiodide is as defect tolerant as lead halide perovskites are. Another interesting fact is, bismuth oxyiodide is stable in air for at least 197 days which is even better than some lead halide perovskite compounds. By sandwiching the bismuth oxyiodide between two oxide electrodes, the researchers successfully converted 80% of light to electrical charge.

Flat microscope for the brain could help restore lost eyesight

by Jon Fingas @ Engadget:

You’d probably prefer that doctors restore lost sight or hearing by directly repairing your eyes and ears, but Rice University is one step closer to the next best thing: transmitting info directly to your brain. It’s developing a flat microscope (the creatively titled FlatScope) that sits on your brain to both monitor and trigger neurons modified to be fluorescent when active. It should not only capture much more detail than existing brain probes (the team is hoping to see “a million” neurons), but reach levels deep enough that it should shed light on how the mind processes sensory input. And that, in turn, opens the door to controlling sensory input.

Flat microscope for the brain could help restore lost eyesight – [Link]

Next Generation Solar Cell To Absorb Nearly All Solar Spectrum

Next Generation Solar Cell That Can Capture Nearly All Energy of Solar Spectrum

Researchers developed a multijunction solar cell on a GaSb substrate that can efficiently convert the long-wavelength photons typically lost in a multijunction solar cell into electricity. This prototype cell has an efficiency of 44.5% which is higher than conventional solar cells.

Next Generation Solar Cell To Absorb Nearly All Solar Spectrum
Next Generation Solar Cell To Absorb Nearly All Solar Spectrum

A GaAs-based cell is stacked mechanically with the GaSb-based materials to create a four-terminal, five junction cell with a spectral response range covering the region containing greater than 99% of the available direct-beam power from the Sun reaching the surface of the Earth. By comparison, the most typical solar cell can convert only one fourth of the available energy into electricity.

The working principle of this new solar cell is slightly different than the commonly available one. The cell is assembled in a mini-module that has a lens with a geometric concentration ratio of 744 suns. The lenses to concentrate sunlight onto tiny, microscale solar cells. As the solar cells have a very tiny form factor of  1 mm², solar cells using more complicated materials can be developed cost effectively.

The stacked cell acts like a filter with a particular material in each layer to absorb a specific range of wavelength of sunlight. The stacking procedure uses the transfer-printing technique which enables three dimensional modeling of these super-tiny devices with a high degree of precision.

Around 99 percent of the power contained in direct sunlight reaching the surface of Earth falls between wavelengths of 250 nm and 2500 nm. The entire range is not accessible by conventional solar panels as they are made from abundant, cheaper materials, such as silicon. Matthew Lumb, the lead author of the study and a research scientist at the GW School of Engineering and Applied Science, said,

Our new device is able to unlock the energy stored in the long-wavelength photons, which are lost in conventional solar cells, and therefore provides a pathway to realizing the ultimate multi-junction solar cell.

The cost of this specific solar cell is pretty high due to the high-end materials used and complex technologies implemented. However, the researchers achieved the upper limit of possibility in terms of efficiency. The new solar cell shows much promise in spite of being highly expensive. perhaps in future, the production cost can be reduced and the similar solar cell will be available commercially in the market.

Carrageenan is extracted from this red seaweeds

Carrageenan, a seaweed derivative, can stabilize lithium-sulfur batteries surprisingly

Lithium-sulfur batteries are suitable for both vehicle and grid applications as they are ultra-cheap, high-energy devices. Sulfur is a very low-cost material and the energy capacity is much higher than that of lithium-ion. So, lithium-sulfur is one chemistry that can possibly meet the demand for energy storage at a cheap price. However, the serious problem is, lithium-sulfur batteries suffer from significant capacity fading that makes them almost practically unusable. But, Lawrence Berkeley National Laboratory researchers’ recent surprising discovery could fix this problem.

Carrageenan is extracted from this red seaweeds
Carrageenan is extracted from this red seaweeds

The research team at Berkley Laboratory surprisingly found that carrageenan, a substance extracted from red seaweeds, acts as a good stabilizer in lithium-sulfur batteries. Better stability in a battery means more charge-discharge cycle and an extended lifetime. Gao Liu, the leader of the research team, said,

It (Carrageenan) actually worked just as well as the synthetic polymer—it worked as a glue and it immobilized the polysulfide, making a really stable electrode.

Lithium-sulfur batteries are already been used commercially in limited applications but the “critical killer” in the chemistry is that the sulfur starts to dissolve and creates polysulfide shuttling effect. Polysulfide shuttling is the primary cause of failure in lithium-sulfur (Li-S) battery cycling. To solve the problem, the research team was experimenting with a synthetic binder that holds all the active materials in a battery cell together.

A binder is like a glue and battery makers want this glue to be inert. The synthetic polymer Liu experimented with, worked remarkably well. The reason is, by chemically reacting with the sulfur, the binder formed a covalent bonding structure and was able to stop it from dissolving. This finding motivated the researchers to find a natural material that would do the same thing. Finally, they discovered that carrageenan has similar chemical properties as the synthetic polymer they used in their initial experiments.

Bekley Lab's researcher is working with advanced light source
Berkley Lab’s researcher is working with advanced light source

With this discovery to stabilize lithium-sulfur batteries­ Liu now wants to improve the lifetime of lithium-sulfur batteries even further. The target of the researchers is to get thousands of cycles from lithium-sulfur chemistry. They are striving to find answers to questions like after this polymer binds with sulfur, what happens next? How does it react with sulfur, and is it reversible? Liu said,

Understanding that will allow us to be able to develop better ways to further improve the life of lithium-sulfur batteries.

As lithium-sulfur batteries are much more lightweight, cheaper, and have higher energy density compared to lithium-ion batteries, they are ideal for airplanes and drones. Hence, Berkeley Lab researchers’ surprising discovery may be a game changer in the world of batteries.

A New Material For Unbreakable Smart Devices

Most of smartphones parts are made of silicons and other compounds, which are expensive and easily-breakable. This problem is making all of smart devices manufacturers looking for stronger and cheaper solutions.

By combining a set of materials, a group of researchers have successfully discovered a new material which could finally finish the disaster of cracked smartphone and tablet screens. The research group is led by a Queen’s University’s School of Mathematics and Physics researchers, with scientists from Stanford University, University of California, California State University and the National Institute for Materials Science in Japan.

Alongside conducting electricity at novel speeds, the new material is light, durable, and can be easily produced in large conventional semiconductor plants. It is a combination of  C60 fullerenes with layered materials such as graphene and h-BN (boron nitride), which presents a unique material with special properties that will be particularly relevant for use in smart device manufacturing.

This material composition has properties that are not naturally found in other materials. The hBN provides stability, electronic compatibility and isolation charge to graphene, while C60 can transform sunlight into electricity. The combining process is known as “der Waals solids” that allows compounds to be brought together and assembled in a pre-defined way.

The material also could mean that devices use less energy than before because of the device architecture so could have improved battery life and less electric shocks. This cutting-edge research is timely and a hot-topic involving key players in the field, which opens a clear international pathway to put Queen’s on the road-map of further outstanding investigations.
~ Dr Elton Santos, leader of the research group

The research shows that the material has the same properties as silicon, but higher chemical stability, lower weight and greater flexibility. These features would make the screens made of this material more difficult to break.

There is still one problem needs a solution. The graphene and the new material architecture is lacking a ‘band gap’, which is an important property to make active semiconductor devices. The team is planning to solve this using transition metal dichalcogenides (TMDs) which are chemically highly stable and have bandgaps like silicon.

According to the research group, this findings will pave the way for further exploration of new materials in the future. You can find more details about this by reviewing the research paper, which was published in the scientific journal ACS Nano, and by reading the official announcement.

Quantum Internet Is Coming!

Secure and unhackable Internet is a goal of many researchers around the world. This is possible using an invisible quantum physical connections as networking links known as “quantum entanglement“. The main challenge is building  large networks that share entangled links with many particles and network nodes, because adding a node will weak the entanglement.

Researchers from Delft and Oxford have successfully found a way to form a strong entangled link. Their solution relays on merging multiple weaker quantum links into one to build a trustworthy quantum network between several quantum nodes.

The research group in known for its effort on implementing quantum entanglement to realize networking links. Now, they are working to pave the way for constructing the first quantum internet. They used photons to reach up to one kilometer macroscopic distance of quantum information link. They also show that this type of link is safe because the entanglement is invisible to intermediate parties, and the information is safe against eavesdropping.

We could now entangle electrons in additional quantum nodes such that we can extend the number of networking links towards a first real quantum network. Scientifically, a whole new world opens up. In five years we will connect four Dutch cities in a rudimentary quantum network.
– Ronald Hanson, The research group leader

This video demonstrates the new method and how it works:

The research paper was published in Science magazine, you can read it for more information.

Sources: TUDelft, elektor.

A 5nm GAAFET Chip By IBM, Samsung & GlobalFoundries

In less than two years since making a 7nm test node chip with 20 billion transistors, scientists have paved the way for 30 billion switches on a fingernail-sized chip. IBM with its Research Alliance partners, GlobalFoundries and Samsung, have unveiled their industry-first process that will enable production of 5nm chips.

The new 5nm technology is one of the first ICs based on GAAFET (Gate-All-Around) topology transistors and also probably the first serious application of EUV (Extreme UltraViolet) lithography.

5 nm GAAFET IC from IBM, Samsung & GlobalFoundries
5 nm GAAFET IC from IBM, Samsung & GlobalFoundries

Gate-all-around FETs are similar in concept to FinFETs except that the gate material surrounds the channel region on all sides. Depending on design, gate-all-around FETs can have two or four effective gates. Successfully, Gate-all-around FETs have been characterized both theoretically and experimentally. Also, they have been successfully etched onto InGaAs nanowires, which have a higher electron mobility than silicon.

IBM claims that it can fit in up to 30 Billion transistors on the chip using GAAFET on a 50 mm² chip. It’s a big move in the semiconductor world, as designs become increasingly complicated to apply. While comparing 5nm GAAFET to 10nm commercial chips, it will achieve a 40% performance boost and a 75% power consumption reduction, at similar performance levels. These are some big claims, so expect some big changes just around the corner.

“For business and society to meet the demands of cognitive and cloud computing in the coming years, advancement in semiconductor technology is essential,” said Arvind Krishna, senior vice president, Hybrid Cloud, and director, IBM Research. “That’s why IBM aggressively pursues new and different architectures and materials that push the limits of this industry, and brings them to market in technologies like mainframes and our cognitive systems.”

For more information you can visit the official announcement.

reconfigurable 3-in-1 semiconductor device

SUNY Polytechnic Creates 3-in-1 Device That Can Be A Diode, A MOSFET And A BJT

In a recently published study, a team of researchers at SUNY Polytechnic Institute in Albany, New York, has suggested that combining multiple functions in a single semiconductor device can significantly improve device’s functionality and efficiency.

Nowadays, the semiconductor industry is striving to scale down the device dimensions in order to fit more transistors onto a computer chip and thus improve the speed and efficiency of the devices. According to Moore’s law, the number of transistors on a computer chip cannot exponentially increase forever. For this reason, scientists are trying to find other ways to improve semiconductor technologies.

To demonstrate the new technology which can be an alternative to Moore’s law, the researchers of SUNY Polytechnic designed and fabricated a reconfigurable device that can be a p-n diode (which functions as a rectifier), a MOSFET (for switching), and a bipolar junction transistor (or BJT, for current amplification). Though these three devices can be fabricated individually in modern semiconductor fabrication plants, it often becomes very complex if they are to be combined.

reconfigurable 3-in-1 semiconductor device
the reconfigurable 3-in-1 semiconductor device

Ji Ung Lee at the SUNY Polytechnic Institute said,

We are able to demonstrate the three most important semiconductor devices (p-n diode, MOSFET, and BJT) using a single reconfigurable device. We can form a single device that can perform the functions of all three devices.

The multitasking device is made of 2-D tungsten diselenide (WSe2), a new transition metal dichalcogenide semiconductor. This class of materials is special as the bandgap is tunable by varying the thickness of the material. It is a direct bandgap while in single layer form.

Another challenge was to find a suitable doping technique as WSe2 lacks one being a new material. So, to integrate multiple functions into a single device, the researchers developed a completely new doping method. By doping, the researchers could obtain properties such as ambipolar conduction, which is the ability to conduct both electrons and holes under different conditions. Lee said,

Instead of using traditional semiconductor fabrication techniques that can only form fixed devices, we use gates to dope.

These gates can control which carriers (electrons or holes) should flow through the semiconductor. In this way, the ambipolar conduction is achieved. The ability to dynamically change the carriers allows the reconfigurable device to perform multiple functions. Another advantage of using gates in doping is, it saves overall area and enable more efficient computing. As consequence, the reconfigurable device can potentially implement certain logic functions more compactly and efficiently.

In future, researchers plan to investigate the applications of this new technology and want to enhance its efficiency further. As Lee said,

We hope to build complex computer circuits with fewer device elements than those using the current semiconductor fabrication process. This will demonstrate the scalability of our device for the post-CMOS era.

Prosthetics Feeling Is Now Possible With This Implantable Chip By Imec

Imec, the world-leading research and innovation hub in nano-electronics and digital technology, announced last month its prototype implantable chip that aims to give patients more intuitive control over their arm prosthetics. The thin-silicon chip is said to be world’s first for electrode density. Creating a closed-loop system for future-generation haptic prosthetics technology is the aim of researchers.

What is special about this chip?

The already available prosthestics are efficient and have their own key features; like giving amputees the ability to move their artificial arm and hand to grasp and manipulate objects. This is done by reading out signals from the person’s muscles or peripheral nerves to control electromotors in the prosthesis. Good news is that revolutionary features are coming! The future prosthetics will provide amputees with rich sensory content. This can be done by delivering precise electrical patterns to the person’s peripheral nerves using implanted electrode interfaces.

The goal behind working on this new technique is to create a new peripheral nerve interfaces with greater channel count, electrode density, and information stability according to Rizwan Bashirullah, director of the University of Florida’s IMPRESS program (Implantable Multimodal Peripheral Recording and Stimulation System)

Fabricated amazingly in a small scale!

A prototype of ultrathin (35µm) chip with a biocompatible, hermetic and flexible packaging is now available. On its surface are 64 electrodes, with a possible extension to 128. This large amount of electrodes is used for fine-grained stimulation and recording. As the short video shows, the researchers will insert the package and attach it to a nerve bundle using an attached needle which will give better results compared to other solutions usually wrapped around nerve bundles.

“Our expertise in silicon neuro-interfaces made imec a natural fit for this project, where we have reached an important milestone for future-generation haptic prosthetics,” commented Dries Braeken, R&D manager and project manager of IMPRESS at imec. “These interfaces allow a much higher density of electrodes and greater flexibility in recording and stimulating than any other technology. With the completion of this prototype and the first phase of the project, we look forward to the next phase where we will make the prototype ready for long-term implanted testing.”

The Defense Advanced Research Projects Agency’s (DARPA) Biological Technologies Office sponserd this work of University of Florida researchers under the auspices of Dr. Doug Weber through the Space and Naval Warfare Systems Center. For more details about this topic check this article.