Posts belonging to Category electronics

How to “Grow” Billions Of Light Dots Directly On Chips

Researchers from the University of California, Santa Barbara (UCSB), in collaboration with the DARPA, succeeded to grow lasers directly on microchips, a breaktrhrough that will enable the mass-production of inexpensive and robust microsystems that exceed the performance capabilities of current technologies.

Defense systems for instance, such as radar, communications, imaging and sensing payloads rely on a wide variety of microsystems devices. These diverse devices typically require particular substrates or base materials and different processing technologies specific to each application, preventing the integration of such devices into a single fabrication process. Integration of these technologies, historically, has required combining one microchip with another, which introduces significant bandwidth and latency limitations as compared to microsystems integrated on a single chip. Although many photonic components can now be fabricated directly on silicon, realizing an efficient laser source on silicon has proven to be very difficult.
Now, the engineers at UCSB showed it was possible to “grow” or deposit successive layers of indium arsenide material directly on silicon wafers to form billions of light-emitting dots known as “quantum dots.” This method of integrating electronic and photonic circuits on a common silicon substrate promises to eliminate wafer bonding, and has application in numerous military and civilian electronics where size, weight, power and packaging/assembly costs are critical.
laser on chipsDARPA’s Electronic-Photonic Heterogeneous Integration (E-PHI) program has successfully integrated billions of light-emitting dots on silicon to create an efficient silicon-based laser. The Defense Advanced Research Projects Agency (DARPA) is an agency of the United States Department of Defense responsible for the development of new technologies for use by the military.
This method of integrating electronic and photonic circuits on a common silicon substrate promises to eliminate wafer bonding, and has application in numerous military and civilian electronics where size, weight, power and packaging/assembly costs are critical“.“It is anticipated that these E-PHI demonstrator microsystems will provide considerable performance improvement and size reduction versus state-of-the-art technologies,” said Josh Conway, DARPA program manager for E-PHI. “Not only can lasers be easily integrated onto silicon, but other components can as well, paving the way for advanced photonic integrated circuits with far more functionality than can be achieved today.


Carbon NanoTubes Solar Cells Twice More Efficient

Lighter, more flexible, and cheaper than conventional solar-cell materials, carbon nanotubes (CNTs) have long shown promise for photovoltaics. But research stalled when CNTs proved to be inefficient, converting far less sunlight into power than other methods.

Now a research team led by Mark Hersam, professor of materials science and engineering at the McCormick School of Engineering, Northwestern University, has created a new type of CNT solar cell that is twice as efficient as its predecessors. It is also the first CNT solar cell to have its performance certified by the National Renewable Energy Laboratory.

solar cells
The field had been hovering around 1 percent efficiency for about a decade; it had really plateaued,.” Hersam said. “But we’ve been able to increase it to over 3 percent. It’s a significant jump
The problem is that each nanotube chirality only absorbs a narrow range of optical wavelengths,” Hersam said. “If you make a solar cell out of a single chirality carbon nanotube, you basically throw away most of the solar light.”

Hersam’s team made a mixture of polychiral, or multiple chirality, semiconducting nanotubes. This maximized the amount of photocurrent produced by absorbing a broader range of solar-spectrum wavelengths. The cells significantly absorbed near-infrared wavelengths, a range that has been inaccessible to many leading thin-film technologies.
The research is described in the article “Polychiral Semiconducting Carbon Nanotube-Fullerene Solar Cells” in the August 7 issue of Nano Letters.

Medical Nanorobots

Researchers from the Institute of General Physics, the Institute of Bioorganic Chemistry (Russia, Academy of Sciences) and MIPT have made an important step towards creating medical nanorobots. They discovered a way of enabling nano- and microparticles to produce logical calculations using a variety of biochemical reactions.
biological nanorobotsThe scientists draw on the idea of computing using biomolecules. In electronic circuits, for instance, logical connectives use current or voltage (if there is voltage, the result is 1, if there is none, it’s 0). In biochemical systems, the result can a given substance. For example, modern bioengineering techniques allow for making a cell illuminate with different colors or even programming it to die, linking the initiation of apoptosis to the result of binary operations.

Scientists say logical operations inside cells to be a way of controlling biological processes and creating nano-robots, which can deliver drugs on schedule. Calculations using biomolecules inside cells, a.k.a. biocomputing, are a very promising and rapidly developing branch of science, according to the leading author of the study, Maxim Nikitin, a 2010 graduate of MIPT’s Department of Biological and Medical Physics. Biocomputing uses natural cellular mechanisms.

The study paves the way for a number of biomedical technologies and differs significantly from previous works in biocomputing binary operations in DNA, RNA and proteins for over a decade now, but Maxim Nikitin and his colleagues were the first to propose and experimentally confirm a method to transform almost any type of nanoparticle or microparticle into autonomous biocomputing structures that are capable of implementing a functionally complete set of Boolean logic gates (YES, NOT, AND and OR) and binding to a target (such as a cell) as result of a computation.

The prefix “nano” in this case is not a fad or a mere formality. A decrease in particle size sometimes leads to drastic changes in the physical and chemical properties of a substance. The smaller the size, the greater the reactivity; very small semiconductor particles, for example, may produce fluorescent light. The new research project used nanoparticles (i.e. particles of 100 nm) and microparticles (3000 nm or 3 micrometers).

The new work was published on the website of the journal Nature Nanotechnology.

Computer: Nano Optical Cables To Replace Copper

Electrical engineers design nano-optical cables that could replace copper wiring on computer chips. The invention of fibre optics revolutionized the way we share information, allowing us to transmit data at volumes and speeds we’d only previously dreamed of. Now, electrical engineering researchers at the University of Alberta are breaking another barrier, designing nano-optical cables small enough to replace the copper wiring on computer chips. This could result in radical increases in computing speeds and reduced energy use by electronic devices. A new step towards the nanocomputer era.

We’re already transmitting data from continent to continent using fibre optics, but the killer application is using this inside chips for interconnect—that is the Holy Grail,” says Zubin Jacob, an electrical engineering professosr leading the research. “What we’ve done is come up with a fundamentally new way of confining light to the nano scale.
At present, the diameter of fibre optic cables is limited to about one thousandth of a millimetre. Cables designed by graduate student Saman Jahani and Jacob are 10 times smaller—small enough to replace copper wiring still used on computer chips. (To put that into perspective, a dime is about one millimetre thick.)


Cigarette Butts Better Than Graphene To Store Energy

A group of scientists from South Korea have converted cigarette butts into a high-performing material that could be integrated into computers, handheld devices, electrical vehicles and wind turbines to store energy. Presenting their findings today, 5 August 2014, in IOP Publishing’s journal Nanotechnology, the researchers have demonstrated the material’s superior performance compared to commercially available carbon, graphene and carbon nanotubes. It is hoped the material can be used to coat the electrodes of supercapacitors electrochemical components that can store extremely large amounts of electrical energy – while also offering a solution to the growing environmental problem caused by used cigarette filters. It is estimated that as many as 5.6 trillion cigarette butts (equivalent to 766 571 metric tons), are deposited into the environment worldwide every year.

cigarette buttsOur study has shown that used cigarette filters can be transformed into a high-performing carbon-based material using a simple one-step process, which simultaneously offers a green solution to meeting the energy demands of society“, said co-author of the study Professor Jongheop Yi, from Seoul National University. “Numerous countries are developing strict regulations to avoid the trillions of toxic and non-biodegradable used cigarette filters that are disposed of into the environment each year; our method is just one way of achieving this.”


How Bonds Fracture

Looking at the molecular level, in order to understand how bonds fracture, from airplane wings to dental crowns, this is the purpose of a MIT research team. Materials that are firmly bonded together with epoxy and other tough adhesives are ubiquitous in modern life — from crowns on teeth to modern composites used in construction. Yet it has proved remarkably difficult to study how these bonds fracture and fail, and how to make them more resistant to such failures.
Now researchers at MIT have found a way to study these bonding failures directly, revealing the crucial role of moisture in setting the stage for failure.

airplane wingsThe bonding problem is a general problem that is encountered in many disciplines, especially in medicine and dentistry,” says Buyukozturk, whose research has focused on infrastructure, where such problems are also of great importance. “The interface between a base material and epoxy, for example, really controls the properties. If the interface is weak, you lose the entire system.”
The composite may be made of a strong and durable material bonded to another strong and durable material,” Buyukozturk adds, “but where you bond them doesn’t necessarily have to be strong and durable.”
Their findings are published in the journal Proceedings of the National Academy of Science in a paper by MIT professors of civil and environmental engineering Oral Buyukozturk and Markus Buehler; research associate Kurt Broderick of MIT’s Microsystems Technology Laboratories; and doctoral student Denvid Lau, who has since joined the faculty at the City University of Hong Kong.

Thousand Miles Range Electric Car

Imagine owning an electric vehicle that can travel 1,000 miles (1610 km) before needing to be recharged. Now imagine that same vehicle being able to be charged to capacity in less than 5 minutes. Or, imagine owning a smart phone that only needs to be charged once a week and that charge taking less than one minute. Now a little start-up company, HyCarb, led by Sigrid Cottrell, is working to allow that imaginary world to come true. Hyper efficient supercapacitors & batteries are designed by utilizing Nanotechnology and nano-super structure technologies in order to power the next generation of consumer electronics, electric vehicles, military equipment and medical devices. They function as both a battery and a supercapacitor. They provide the long, steady power output comparable to a conventional battery, as well as a supercapacitor’s quick burst of high energy.

2014 Renault

HyCarb, Inc. is a Florida-based, for-profit, small business, headquartered at the UCF Business Incubator in Research Park. The team of researchers has already filed 3 patents protecting the system of processes required to generate a Hy-Carb supercapictor battery develops nanostructured materials using high-throughput combinatorial electrochemical methods and other proprietary techniques.

Nano-engineered battery/super capacitor is lightweight, ultra thin, completely flexible, and geared toward meeting the trickiest design and energy requirements of tomorrow’s gadgets, electric vehicles, implantable medical equipment and any number of other applications. aligned carbon nanotubes, which will give the device its black color. The nanotubes act as electrodes and allow the storage devices to conduct electricity.
The creation of this unique nano-composite surface drew from a diverse pool of disciplines, requiring expertise in materials science, energy storage, and chemistry. Along with use in small handheld electronics, the batteries’ lighter weight could make them ideal for use in automobiles, aircraft, and even boats. The Hy-Carb Supercapicitor could also be manufactured into different shapes, such as a car door, which would enable important new engineering innovations. .

Face Recognition Approaches One Hundred Percent Accuracy

A research team at the Chinese University of Hong Kong, led by Professor Xiaoou Tang, announced 99.15% face recognition accuracy achieved in Labeled Faces in the Wild (LFW) database (a database of face photographs designed for studying the problem of unconstrained face recognition).
The technology developed by Xiaoou Chen’s team is called DeepID, which is more accurate than visual identification.

face recognition
LFW is the most widely used face recognition benchmarks. Experimental results show that, if only the central region of the face is given, with the naked eye in the LFW person recognition rate is 97.52%

The three face recognition algorithms developed by Xiaoou Chen’s team now occupies the top three LFW recognition accuracy rate, followed by Facebook’s Deepface.

His lab has been based on the latest technological breakthroughs to produce a complete set of facial image processing system (SDK), including face detection, face alignment of key points, face recognition, expression recognition, gender recognition, age estimation

Xiaoou Tang plans to provide face recognition technology for free to Android, iOS and Windows Phone developers; with the help of this FreeFace-SDK, the developer can develop a variety of applications based on face recognition on the phone.


Sniffing Out Explosives, Better Than Trained Dogs

Tel Aviv University researchers have built a groundbreaking sensor that detects miniscule concentrations of hazardous materials in the air. Security forces worldwide rely on sophisticated equipment, trained personnel, and detection dogs to safeguard airports and other public areas against terrorist attacks. A revolutionary new electronic chip with nano-sized chemical sensors is about to make their job much easier. The groundbreaking nanotechnology-inspired sensor, devised by Prof. Fernando Patolsky of Tel Aviv University‘s School of Chemistry and Center for Nanoscience and Nanotechnology, and developed by the Herzliya company Tracense, picks up the scent of explosives molecules better than a detection dog’s nose.
Existing explosives sensors are expensive, bulky and require expert interpretation of the findings. In contrast, the new sensor is mobile, inexpensive, and identifies in real time — and with great accuracy explosives in the air at concentrations as low as a few molecules per 1,000 trillion.
explosive detective dog
Using a single tiny chip that consists of hundreds of supersensitive sensors, we can detect ultra low traces of extremely volatile explosives in air samples, and clearly fingerprint and differentiate them from other non-hazardous materials,” said Prof. Patolsky, a top researcher in the field of nanotechnology. “In real time, it detects small molecular species in air down to concentrations of parts-per-quadrillion, which is four to five orders of magnitude more sensitive than any existing technological method, and two to three orders of magnitude more sensitive than a dog’s nose. “This chip can also detect improvised explosives, such as TATP (triacetone triperoxide), used in suicide bombing attacks in Israel and abroad,” Prof. Patolsky added.
Research on the sensor was recently published in the journal Nature Communications.


How To Embed Semiconductor Crystals Into A Nanowire

Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Germany), the Vienna University of Technology (Austria) and the Maria Curie-Skłodowska University Lublin (Poland) have succeeded in embedding nearly perfect semiconductor crystals into a silicon nanowire. With this new method of producing hybrid nanowires, very fast and multi-functional processing units can be accommodated on a single chip (nanocomputer) in the future.
Nano-optoelectronics are considered the cornerstone of future chip technology. Scientists have now come a step closer to both these targets: they integrated compound semiconductor crystals made of indium arsenide (InAs) into silicon nanowires, which are ideally suited for constructing increasingly compact chips.

This integration of crystals was the greatest obstacle for such “hetero-nanowires” until now: beyond the nanometer range, crystal lattice mismatch always led to numerous defects. The researchers have now managed a near-perfect production and embedding of the InAs crystals into the nanowires for the first time.
iridium arsenide

Indium arsenide (green-cyan) is perfectly integrated into the silicon nanowire (blue). (Energy-dispersive X-ray spectroscopy). The energy-dispersive X-ray spectroscopy (colored pricture) was performed at École polytechnique fédérale de Lausanne, Switzerland.

The research results will be published in the journal Nano Research.