Thinnest bulb in the world

Scientists have demonstrated, for the first time, an on-chip visible light source using graphene as a filament. They attached small strips of graphene to metal electrodes, suspended the strips above the substrate, and passed a current through the filaments to cause them to heat up. This was achieved by James Hone’s group at Columbia Engineering, a team of scientists from Columbia University, Seoul National University (SNU), and Korea Research Institute of Standards and Science (KRISS), led by Young Duck Kim, a postdoctoral research scientist.

Wang Fon-Jen professor of mechanical engineering at Columbia Engineering and co-author of the study said that “We’ve created what is essentially the world’s thinnest light bulb,”.“This new type of ‘broadband’ light emitter can be integrated into chips and will pave the way towards the realization of atomically thin, flexible, and transparent displays, and graphene-based on-chip optical communications" he added.

For developing fully integrated “photonic” circuits, creating light in small structures on the surface of a chip is crucial. In spite of huge amount of efforts from researchers, they still haven't developed, a way to put the oldest and simplest artificial light source the incandescent light bulb onto a chip. This is because of the reason that light bulb filaments must be extremely hot nearly thousands of degrees Celsius in order to glow in the visible range but micro-scale metal wires cannot withstand such temperatures, in addition to that heat transfer from the hot filament to its surroundings is extremely efficient at the microscale, which makes such structures impractical and leads to damage of the surrounding chip.

By measuring the spectrum of the light emitted from the graphene, the team was able to show that the graphene was reaching temperatures of above 2,500 C, hot enough to glow brightly. Kim, first and co-lead author on the paper said “The visible light from atomically thin graphene is so intense that it is visible even to the naked eye, without any additional magnification,”.

Interestingly, the spectrum of the emitted light showed peaks at specific wavelengths, which the team discovered was due to interference between the light emitted directly from the graphene and light reflecting off the silicon substrate and passing back through the graphene. Kim notes, “This is only possible because graphene is transparent, unlike any conventional filament, and allows us to tune the emission spectrum by changing the distance to the substrate.”

As graphene heats up, it becomes a much poorer conductor of heat. This means that the high temperatures stay confined to a small “hot spot” in the center, due to this property graphene is able to achieve high temperatures without melting the substrate or the metal electrodes. Myung-Ho Bae, a senior researcher at KRISS and co-lead author said " At the highest temperatures, the electron temperature is much higher than that of acoustic vibrational modes of the graphene lattice, so that less energy is needed to attain temperatures needed for visible light emission,”.“These unique thermal properties allow us to heat the suspended graphene up to half of the temperature of the sun, and improve efficiency 1000 times, as compared to graphene on a solid substrate," he added.


Yun Daniel Park, professor in the Department of Physics and Astronomy at Seoul National Univ. and co-lead author, notes that they are working with the same material that Thomas Edison used when he invented the incandescent light bulb: “Edison originally used carbon as a filament for his light bulb and here we are going back to the same element, but using it in its pure form—graphene—and at its ultimate size limit—one atom thick.”

The group is currently working to further characterize the performance of these devices—for example, how fast they can be turned on and off to create “bits” for optical communications—and to develop techniques for integrating them into flexible substrates.


Hone adds, “We are just starting to dream about other uses for these structures—for example, as micro-hotplates that can be heated to thousands of degrees in a fraction of a second to study high-temperature chemical reactions or catalysis.”

Source: R&D Magzine

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Technology can make Night visions and thermal imaging devices affordable to all

Semiconductor technology that could make night vision and thermal imaging affordable for everyday use was created by Engineers at the University of Texas at Dallas.Researchers in the Texas Analog Center of Excellence (TxACE) in the university’s Erik Jonsson School of Engineering and Computer Science created an electronic device that detects electromagnetic waves to create images at nearly 10 THz, which is the highest frequency for electronic devices. The device could cut off the cost of night visions and thermal imaging devices.


The present night vision and thermal imagers are costly because they are made with special semiconductor devices and need isolation from the environment, but the UT Dallas device is created using Schottky diodes (semiconductor diode with a low forward voltage drop and a very fast switching action) in complementary metal-oxide semiconductor (CMOS) technology.CMOS is also used to make electronic devices such as personal computers(PC's), gaming consoles and high-definition TVs. In addition to being relatively cheap these devices can also be easily incorporated into smartphones.

Zeshan Ahmad, lead author of the work, electrical engineering doctoral candidate and a research assistant in TxACE said that “There are no existing electronic detection systems operating in CMOS that can reach above 5 THz,”.“We designed our chip in such a way that it can be mass produced inexpensively, has a smaller pixel and operates at higher frequencies.” he added.

“This is a truly remarkable accomplishment,”  said Dr. Kenneth O professor of electrical engineering in the Jonsson School and director of TxACE and also holder of the TEXAS INSTRUMENTS Distinguished Chair.“Twenty years ago, we were struggling to build CMOS circuits operating at 1 GHz. Now we are building circuits working at frequencies that are 10,000 times higher.” he added.

There are numerous applications of the device, such as:

• Imaging animals near a road while driving at night.
• Imaging intruders in darkness by military.
• Providing light for night hiking.
• Estimating how many people are in a room to better control heating, air conditioning and light.
• Even for ghost hunting.

Dr. Robert Doering, research strategy manager at Texas Instruments said that “This technology could provide a very superior means to use the infrared portion of the spectrum,”. “Electronic control of generating infrared directly from CMOS integrated circuits will enable a wide variety of important new applications.” he added.

Realizing CMOS devices that can reach even higher frequencies, up to 40 THz will be the next step.

Related posts:Skin sensitive smartphones

Source:R&D Magazine 

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PPT on 8251 USART(Universal Synchronous Asynchronous Receiver Transmitter)

The 8251 USART is typically used for serial communication and was rated for 19.2 Kilo bits per second signalling rate.It is commonly confused with the much more common 8250 UART that was made popular as the serial port in the IBM Personal Computer.

It has 5 sections:

• read/write control logic
• transmitter
• receiver
• data bus system
• modem control

Contents of ppt:

• INTRODUCTION
• SYNCHRONOUS COMMUNICATION
• ASYNCHRONOUS COMMUNICATION
• BLOCK DIAGRAM
• TRANSMITTER
• RECEIVER
• PIN DIAGRAM
• PIN DESCRIPTION
• APPLICATIONS

PPT:

                                                 


Related posts:Ppt on proximity sensors, Ppt on wave theory propogation

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Now smartphones can be used by touching your skin

People wearing a smartwatch can look at the calender or receive emails without having to reach further than their wrist. However, the interaction area offered by the watch is so small that sometimes it's really difficult to tap the individual buttons precisely.

A team of computer scientists from Saarbrucken in collaboration with researchers from Carnegie Mellon University in the USA may provide a solution to this problem, they have created a flexible sensor that could be stuck to the skin and used to control your phone.These touch-sensitive sensors are in the form of stickers that are made from flexible silicone and electrically conducting sensors.

The stickers act as an input space that receives and executes commands, and thus control mobile devices depending on the type of sticker used, for example tasks like answering a call or adjusting the volume of a music player can be accomplished just by applying pressure on the sticker. Martin Weigel, a PhD student in the team led by Jurgen Steimle at the Cluster of Excellence at Saarland University says that " The stickers allow us to enlarge the input space accessible to the user as they can be attached practically anywhere on the body,".

The iSkin approach enables the human body to become more closely connected to technology. Users can also design their iSkin patches on a computer beforehand to suit their individual styles."A simple graphics program is all you need," Weigel added.

One sticker ,for instance, is based on musical notation, another is circular in shape like an LP. The silicone used to fabricate the sensor patches makes them flexible and stretchable. " This makes them easier to use in an everyday environment. The music player can be simply rolled up and put in a pocket ," explains Jurgen Steimle, who heads the 'Embodied Interaction Group'  in which Weigel is doing research.The Stickers are very much skin friendly as they are attached to the skin with a biocompatible, medical-grade adhesive. Users can therefore decide where they want to position the sensor patch and how long they want to wear it.

In addition to controlling the the music player or phone calls, the iSkin can also be used for many other applications such  as, a keyboard sticker could be used to type and send messages or to type and send emails.Currently the sensor stickers are connected using cable to a computer system, but according to Steimle, in future the skin-worn sensor patches may communicate wirelessly with other mobile devices using in built microchips.

Related posts:Great plans for QR codes, Superfast computers, Night visions and thermal imaging

Source: Mumbai Mirror

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Silicene holds the promise for super-fast computer chips

One atom thick layer of silicon atoms is called as Silicene. Researchers at the University of Texas at Austin's Cockrell School of Engineering have created the first transistors made of silicene, the world’s thinnest silicon material.Their research holds the promise of building dramatically faster, smaller and more efficient computer chips.

Silicene has outstanding electrical properties but has until now proved difficult to produce and work with.One of the major challenges surrounding silicene was solved by Deji Akinwande, an assistant professor in the Cockrell School’s Department of electrical and computer engineering, and his team, including lead researcher Li Tao, they demonstrated that silicene can be made into transistors which are semiconductor devices used to amplify and switch electronic signals and electrical power.

Honeycomb lattice structure of Silicene

The first of their kind devices developed by Akinwande and his team rely on the thinnest of any semiconductor material it is a long-standing dream of the chip industry, and could carve the way for future generations of faster and energy efficient computer chips. Their work was published in Nature Nanotechnology.

Until a few years ago, silicene was a purely theoretical material the idea was inspired by looking at carbon-based graphene, another atom-thick material with promise for chip development, researchers speculated that silicon atoms also can be structured in a broadly similar way. Akinwande, who also works on graphene transistors, sees value in silicene's relationship to silicon, which chipmakers already know how to work with.

Akinwande said that "Apart from introducing a new player in the playground of 2-D materials, silicene, with its close chemical affinity to silicon, suggests an opportunity in the road map of the semiconductor industry,”.“The major breakthrough here is the efficient low-temperature manufacturing and fabrication of silicene devices for the first time.”he added

Due to silicene complexity and instability when exposed to air, it is extremely difficult to create and work with.To overcome these issues, Akinwande teamed with Alessandro Molle at the Institute for Microelectronics and Microsystems in Agrate Brianza, Italy, to develop a new method for fabricating the silicene that reduces its exposure to air.For starters the researchers let a hot vapour of silicon atoms condense onto a crystalline block of silver in a vacuum chamber. Then they formed a silicene sheet on a thin layer of silver and added a thick layer of alumina on top which in the order of nanometers.Because of these protective layers, the team could safely peel it of its base and transfer it silver-side-up to an oxidized-silicon substrate. They were then able to gently scrape some of the silver to leave behind two islands of metal as electrodes, with a strip of silicene between them.

Akinwande will continue to investigate the possible new structures and methods for creating silicene, which may help to create low-energy and high-speed digital computer chips. 

Related posts:Supercomputers

Source:R&D Magazine 

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Transparent display, a definite possibility

Responsive transparent displays that don't need an internal light source and can be easily integrated on windows and glasses can be made using the optical features embedded in marine shells.

The scientists at MIT and Havard have identified two optical structures within the limpet's( it is an aquatic snail with a shell broadly conical in shape) shell that give its blue stripped appearance.The structures are configured to reflect blue light while absorbing all other wavelengths of incoming light.The findings in the journal Nature Communications, represent the first evidence of an organism using mineralised structural components to produce optical displays.While birds, butterflies, and beetles can display brilliant blues, among other colours, they do so with organic structures, such as feathers, scales, and plates.The limpet by contrast produces its blue stripes through an interplay of inorganic, mineral structures, arranged in such a way as to reflect only blue light.They sat such optical structures may serve as a design guide for engineering colour-selective, controllable, transparent displays that require no internal light source and could be incorporated into windows and glasses.

"Lets imagine a window surface in a car where you obviously want to see the outside world as you're driving, but where you also can overlay the real world with an augmented reality that could involve projecting a map and other useful information on the world that exists on the other side of the windshield," says co-author Mathias Kolle. "We believe that the limpet's approach to displaying colour patterns in a translucent shell could serve as a starting point for developing such displays."

Kolle, whose research is focused on engineering bioinspired, optical materials including colour changing, deformable fibres started looking into the optical features of the limpet when his brother Stefan, a marine biologist now working at Havard, brought Kolle a few of the organisms in a small container.Stefan Kolle was struck by the mollusc's brilliant patterning, and recruited his brother, along with several others, to go deeper into the shell's optical properties.

To do this, they performed a detailed structural and optical analysis of the limpet shells.They observed that the blue stripes first appear in the juveniles, resembling dashed lines.The stripes grow more continuous as a limpets matures, and their shade varies from from individual to individual, ranging from deep blue to turquoise.

The researchers scanned the surface of a limpet's shell using scanning electron microscopy, and found no structural differences in areas with and without the stripes-an observation that led them to think that perhaps the stripes arose from features embedded deeper in the shell.To get a picture of what lay beneath, the researchers used a combination of high-rsolution 2-D and 3-D structural analysis to reveal the 3-D nanoarchitecture of the limpet's translucent shells.

What they found was revealing: In the regions with blue stripes, the shell's top and bottom layers were relatively uniform, with dense stacks of calcium carbonate platelets and thin organic layers, similar to the shell structure of other molluscs.However, about 30 microns beneath the shell surface the researchers noted a stark difference.In these regions, the researchers found that the regular plates of calcium carbonate morphed into two distinct structural features: a multilayered structure with regular spacing between calcium carbonate layers resembling a zig-zag pattern and beneath this layer of randomly dispersed, spherical particles.

The researchers measured the dimensions of the zigzagging plates, and found the spacing between them was much wider than the more uniform plates running through the shell's unstripped sections,They then examined the potential roles of both the multilayer zigzagging structure and the spherical particles.They used optical microscopy, spectroscopy, and diffraction microscopy to quantify the blue stripe's light-reflection properties. They then measured the zigzagging structures and their angle with respect to the shell surface, and determined that this structure is optimised to reflect blue and green light,The researchers also determined that the disordered arrangement of spherical particles beneath the zigzag structures serves to absorb transmitted light that otherwise could de-saturate the reflected clue colour.

From these results, Kolle and his team deduced that the zigzag pattern acts as a filter, reflecting only blue light. As the rest of the incoming light passes through the shell, the underlying particles absorb this light-an effect that makes shell's stripes appear even more brilliantly blue.

Related posts: 3-D displays without glasses

Source: Mumbai Mirror
  

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Great future plans for QR codes

QR(quick response) code are those which are usually in black and white boxes that people scan with their mobile phones to download or to know more about something.The researchers from the  University of Connecticut says that these can even take care of national security.

Board of Trustees Distinguished Professor Bahram Javidi said that “An optical code or QR code can be manufactured in such a way that it is very difficult to duplicate,”. “But if you have the right keys, not only can you authenticate the chip, but you can also learn detailed information about the chip and what its specifications are" he added.


Used computer chips doesn't matter much when in the case of poor cell phone reception or an laptop computer crash in personal use, but the problem becomes exponentially more serious when counterfeit or hacked chips turn up in nation's military force.

Unlike commercial QR codes, Javidi’s little black and white boxes can be scaled as small as microns or a few millimeters and would replace the electronic part number that is currently stamped on most microchips.

Javidi also says that he can compress vital information about a chip i.e its functionality, capacity and part number, directly into the QR code so that it can be obtained by the reader without having access to the internet, and this is important in cybersecurity circles, because by linking to the Internet means great increase chances of hacking or corruption.

Javidi has also applied an optical imaging mask which scrambles the QR code design into a mass of black and white pixels which looks similar to the images seen on a broken television, to ensure proper security. He then added another layer of security through a random phase photon based encryption that turns the snowy image into a darkened night time sky with just a few random stars or dots of pixilated light.

The end result of all these layering is a highly secure, microscopic design that is next to impossible to duplicate. Only the individuals with special corresponding codes can decrypt the QR image.

Related posts:Super fast computers, Smartphones

Source:R&D Magazine 

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Future of quantum radar

An international research team led by a quantum information scientist at the University of York built a prototype quantum radar that has the potential to detect objects that are invisible to conventional systems.

This new breed of radar is a hybrid system which uses quantum correlation between microwave and optical beams to detect the objects that has low reflectivity such as cancer cells or aircraft. The radar operates at lower energies compared to the conventional systems and therefore it has a long-term potential for numerous applications in biomedicine including non-invasive NMR scans.

A special converter—a double-cavity device that couples the microwave beam to an optical beam using a nanomechanical oscillator—was the key to the new system which was found by the research team led by Dr. Stefano Pirandola, of the university’s Department of Computer Science and the York Centre for Quantum Technologies.

 Quantum radars exploit quantum entanglement to enhance their sensitivity to detect even small signal reflections from very noisy regions, whereas the classical radar systems emits a microwave to scan a region of space and any target object present there would reflect the signal to the source, but the objects with low reflectivity immersed in regions with high background noise are very difficult to spot. Dr. Pirandola said that while quantum radars were some way off, they would have superior performance especially at the low-photon regime.

“Our method could be used to develop non-invasive NMR spectroscopy of fragile proteins and nucleic acids. In medicine, these techniques could potentially be applied to magnetic resonance imaging, with the aim of reducing the radiation dose absorbed by patients.” he added.

In coming future, this scheme could be operated at short distances to detect the presence of defects in biological samples or human tissues in a completely non-invasive fashion, thanks to the use of a low number of quantum-correlated photons.

Source:R&D Magazine 

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Now 3-D displays without glasses is possible

Thanks to a new invention from Austrian scientists, in the future we will be able to enjoy public screenings in 3-D, which have become an important part of major sports events. A sophisticated laser system sends laser beams into different directions due to which different pictures are visible at different angles and the angular resolution is so fine that the left eye sees a different picture than the right one which creates a 3-D effect.

In 2013, a startup company TriLite Technologies had the idea to develop this new kind of display, which sends beams of light directly to the viewers' eyes. This project was carried out together with the Vienna University of Technology.

TriLite and TU Vienna together have created the first prototype, for now it only has a modest resolution of five pixels by three. Jörg Reitterer (TriLite Technologies and graduate student in the team of Prof. Ulrich Schmid at the Vienna Univ. of Technology) says that "We are creating a second prototype, which will display colour pictures with a higher resolution. But the crucial point is that the individual laser pixels work. Scaling it up to a display with many pixels is not a problem,".

Every single 3-D-Pixel also called as trixel consists of lasers and a moveable mirror. Ulrich Schmid says that "The mirror directs the laser beams across the field of vision, from left to right. During that movement the laser intensity is modulated so that different laser flashes are sent into different directions,". The viewer must be positioned at a certain distance range from the screen so as to experience the 3-D effect. If the person isn't in the range then both the eyes will receive the same image and a normal 2-D picture would be seen. The range to experience 3-D effect can be tuned according to the local requirements.

Unlike the 3-D movies in the cinemas that only shows two different pictures—one for each eye, This newly developed display, is capable of presenting hundreds of pictures. One can get a view of the displayed object from different sides, while walking by the display just like while passing a real object.For this, a new video format is required, which has already been developed by the researchers. Franz Fiedler, CTO of TriLite Technologies says that "Today's 3-D cinema movies can be converted into our 3-D format, but we expect that new footage will be created especially for our displays—perhaps with a much larger number of cameras,".

Since the display is very vivid, it can be used outdoors, even in bright sunlight.Electronic billboards could display different ads, seen from different angles. Ferdinand Saint-Julien, CEO of TriLite Technologies says that "Maybe someone wants to appeal specifically to the customers leaving the shop across the street, and a different ad is shown to the people waiting at the bus stop,". This would not be a problem technologically.

It took only three years to get from the first designs to a working prototype."We are very happy that the project was so successful in such a short period of time," says Schmid. This technology has now been patented and presented in several scientific publications, and the second prototype would probably be finished by the middle of the year and the commercial launch is scheduled for 2016.


Related posts:3-D printing, Transparent display

Source:R&D Magazine 

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3D-print jet engines

Researchers for the first time in the world, printed two jet engines using sophisticated 3D printers that can make complex objects using metals like titanium and aluminium.This has attracted the interest of major manufacturers and engineering firms.The machines produced using the template of a gas turbine engine from French aircraft engine maker Safran, which supplies Airbus and Boeing-demonstrated the potential 3D printing had to produce high-quality products, researchers from Melbourne's Monash University said.

The university's Ian Smith said that "the significance is the recognition by major manufacturers and engineering companies like Safran and Airbus that the material you can print using 3D metal printing is of aircraft quality and I think that's hugely significant"."It's a disruptive technology. We've seen a lot happening in the plastics and polymer space but this is exciting because it's now metals and light metals and things like titanium nickel and aluminium" he added.

3D printing was invented in the 80's and employs laser to "print" objects from metals or plastics according to a digital design.There has been a recent upsurge in interest tied to patents on the way for competition that will drive up quality and push down prices.Wu Xinhua, from Monash University said her team created the machines by pulling apart the old engine and scanning its components with the complex project taking a year to complete.

One of the engines are in display at the International Airshow in Melbourne and in Toulouse at the French aerospace company Microturbo. The head of the research and technology at Microturbo  Jean-Francois Rideau said that" Xinhua and her Monash team have demonstrated their mastery of additive manufacturing in metal".

Smith said that the technology could also be used in building prototypes and customised components quickly and cheaply. The 3D metal printers could also be used in the biomedical industry to create body parts or equipments Some of the biggest opportunities lies in the medical space where bespoke parts for the body-replacement joints and hips can be made.

"A lot of surgeons want to make their own instruments that are customised for them or a particular surgical procedure" he said.

Related posts:3-D displays without glasses

Source; Mumbai Mirror

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NEMS lab on a chip revolution set by Optical nanoantennas

Australian scientists created tiny antennas, likened to spotlights on the nanoscale which offers the potential to measure food safety, identify pollutants in the air and even quickly diagnose and treat cancer.The new antennas are cubic in shape and it does a better job than the previous spherical ones at directing an ultra-narrow beam of light, with little or no loss due to heating and scattering.

Debabrata Sikdar, a doctoral research student from India (a Birla Institute of Technology & Science (B.I.T.S.), Pilani Alumnus) working with 'Victoria India Doctoral Scholarship' at Monash University in Victoria, Australia, describe these and other envisioned applications for their nanocubes in "laboratories-on-a-chip." These cubes are composed of insulating materials, rather than conducting or semiconducting materials, he says.


Sikdar's paper presents analysis and simulation of 200-nm dielectric nanoncubes placed in the path of visible and near-infrared light sources. The nanocubes are arranged in a chain, and the space between them can be adjusted to fine-tune the light beam as needed for various applications. As the separation between cubes goes on increasing, the angular width of the beam narrows and directionality improves, the researchers say.

In an interview Sikdar said that "Unidirectional nanoantennas induce directionality to any omnidirectional light emitters like microlasers, nanolasers or spasers, and even quantum dots,". Quantum dots are tiny crystals that produce specific colors, based on their size, and are widely used in colour televisions. He also said that "Analogous to nanoscale spotlights, the cubic antennas focus light with precise control over direction and beam width,".

The new cubic nanoantennas have the potential to revolutionize the infant field of nano-electromechanical systems (NEMS)."They can potentially replace the lossy on-chip IC (integrated circuit) interconnects, via transmitting optical signals within and among ICs, to ensure ultrafast data processing while minimizing device heating,"Sikdar said."These unidirectional nanoantennas are also the most suitable for integrated optics-based biosensors to detect proteins, DNA, antibodies, enzymes, etc., in truly portable lab-on-a-chip platforms of the future,"he added.

Sikdar and his colleagues plan to begin constructing unidirectional cubic NEMS antennas in the near future at the Melbourne Center for Nanofabrication.

Source: Mumbai Mirror

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Armband that can sound alarm if you have fever

Japanese researchers have developed a armband that produces sound if you have fever. It is flexible, self-powered, wearable device that goes of in case of  high body temperature. The flexible organic components developed for this device are well-suited to wearable devices that continuously monitor vital signs including temperature and heart rate for applications in healthcare.
Professor Takao Someya from the University of Tokyo's graduate school of engineering says that "The fever alarm armband demonstrates that it is possible to produce flexible, disposable devices that can greatly enhance the amount of information available to carers in healthcare settings".The system could also be adapted to provide audible feedback on body temperature, or combined with other sensors to register wetness, pressure or heart rate, he added.
This device combines a flexible amorphous silicon solar panel, piezoelectric speaker, temperature sensor and power supply circuit created with organic components in a single flexible wearable package. Sensors for such applications need to be flexible and wireless for patient comfort, maintenance free and not requiring external energy supply, and cheap enough to permit disposable use to ensure hygiene.
The fever alarm armband incorporates several first-ever achievements. It is the first organic circuit able to produce a sound output, and the first to incorporate an organic power supply circuit. The former enables the device to provide audible information when the flexible thermal sensor detects a pre-set value within the ranges of 36.5  C to 38.5 C, while the latter increases the range of operational illumination by 7.3 times in indoor lighting conditions.
"Conventional sensors based rigid components are unable to meet these requirements, so we have developed a flexible solution that incorporates organic components that can be printed by an inkjet printer on polymeric film" concluded co-author Sakurai from the Institute of Industrial Science.

Source:R&D Magazine 
   

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Fibre based electronic devices : Seminar topic

Weaving of electronics into any material

Scientists have always been known for doing impossible things and now a group of scientists from Massachusetts Institute of Technology (MIT) have done yet another thing by using two abundant raw materials to create fibre of pure crystalline silicon which could be used to add electronics, including microchips and solar cells, to almost any fabric.

The idea grew out of a long-term research effort to develop multifunctional fibres that incorporate different materials into a single long functional strand.

Until now, those long strands could only be created by arranging the materials in a large block or cylinder called a preform, which is then heated and stretched to create a thin fibre that is drastically smaller in diameter, but retains the same composition, but now for the first time, fibres created through this method can have a composition that's completely different from that of the starting materials.The new findings are described in paper in the journal 'Nature Communications' co-authored by Chong Hou, and six others at MIT and in Singapore.

The fibres are made from aluminium metal and silica, abundant low cost materials, which are commonly used to make window frames. The aluminium metal and silica glass react chemically as they are heated and drawn, producing a fibre with a core of pure, crystalline silicon-the raw material of computer chips and solar cells-and a coating of silica.

Hou tried a variety of metals, including silver, copper and aluminium-and in the latter case the result was not what they expected.When the scientists looked at the fibre, instead of a shiny metallic core, they observed a dark substance and they found that the core had silicon-in fact, very pure, crystalline silicon.It turned out that the chemical reaction in the fibre was well known one: At high temperatures used for drawing the fibre, about 2200 degree celsius, the pure aluminium core reacted with the silica, a form of silicon oxide.

This reaction left behind pure silicon, concentrated in the core of the fibre and aluminium oxide, which deposited a very thin layer of aluminium between the core and the silica cladding.

Now, Hou says,"We can use this to get electrical devices, like solar cells or transistors, or any silicon-based semiconductor devices, that could be built inside the fibre." Many teams, have tried to create such devices within fibres, he says, but so far all of the methods tried have required starting with expensive, high-purity silicon. A team is also working to produce specific structures, such as an electrical junction inside the material as it is drawn so that metals like gold or copper can be put in there to make a real electrical circuit.

Scientists also say that "This technology could open up new possibilities for electronics-including solar cells and microchips-to be incorporated into fibres and woven into clothing or accessories.    

Related posts:Gold nanotubes , Nano-hydrogels

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Gold Nanotubes : Seminar Topic

A demonstration of the biomedical use of gold nanotubes in a mouse model of human cancer was conducted successfully and soon it would be heading for clinical trials.

High recurrence rates of tumours after surgical removal remain a formidable challenge in cancer therapy. Chemo or radiotherapy is often given following surgery to prevent this, but these treatments cause serious side effects.

Gold nanotubes resembles tiny drinking straws and have the potential to enhance the efficiency of these conventional treatments by integrating diagnosis and therapy in one single system.The researchers say that a new technique to control the length of nanotubes underpins the research, by controlling the length the researchers were able to produce gold nanotubes with the right dimensions to absorb a type of light called 'near infrared'.

When the gold nanotubes travel through the body, if light of the right frequency is shone on them they absorb the light. this light energy is converted to heat, rather like the warmth generated by the sun on skin. Using a pulse laser beam the researches were able to rapidly raise the temperature in the vicinity of the nanotubes  so that it was high enough to destroy cancer cells.

In order to see the gold nanotubes in the body , the researches used a new type of imaging called 'multispectral optoacoustic tomography' (MSOT) to detect the gold nanotubes in mice, in which gold nanotubes had been injected intravenously. It is the first biomedical application of gold nanotubes within a living organism. it was also shown that gold nanotubes ere excreted from the body and therefore are unlikely to cause problems in terms of toxicity, an important considered when developing nanoparticles for clinical use.

The use of gold nanotubes in imaging other biomedical applications is currently progressing through trial stages towards early clinical studies.

Related posts:Fibre electronics , Nano-hydrogels

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NANO-HYDROGELS : Seminar Topic

NANO-HYDROGELS FINDS AND KILLS CANCER CELLS

Hydrogels are materials that are commonly used in day to day life in objects such as contact lens or diapers,in order to control humidity.Chemical engineers at the University of Guadalajara (UdeG), in Mexico have developed a new technology that uses thermosensitive nanoparticles (nano-hydrogels) to control the release of anyicancer drugs inside the human body.The basic idea behind this is that the drug can be enclosed within the nano-hydrogelsand transported directly to cancer cells whrer it can be released without damaging other parts of the body.

This is possible because the medicine can be transported to the desired site by different routes like oral, nasal, buccal, rectal and even ocular.The drug release can be triggered by a change in pH levels, or temperature.

This new advancement  lets the researchers add magnetic particles to the hydrogels in order to produce a force field to raise the temperature, which is necessary to destroy cancer cells.

PRODUCTION

The thermosensitive nano-hydrogels which through a polymerisation technique, mixes substances eith different chemical and physical characteristics, achieving chemical reaction and forming a set of small spheres called polymers.By combining emulsion polymerization and microemulsion the researchers were able to synthesise hydrogels which have better mechanical properties than conventional hydrogels.

APPLICATION

These materials are used primarily in the biomedical area as diagnostic membranes, coatings, microcapsules,implants for applications of short or long-range and systems of controlled drug release. It could also be used to regenerate tissue or mend fractures, serving as substrates for cell growth.

The nano-hydrogels have shown very good characteristics of biocompatibility with human body, due to their physical properties which make them resemble living tissues, especially by its high water content, its elastic consistency, and its low interfacial tension which prevents them from absorbing proteins from body fluids.

Related posts:Gold nanotubes , Fibre electronics

Source: Mumbai Mirror

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11 easy steps to give a paper presentation

Here are some of the easy steps that you should follow before giving a Paper Presentation :

1. Firstly you should double check that the topic you choose is fresh i.e submitting ppt on Nano Technology wont be selected ,as their are many articles published on this topic and many submission comes from such topics which gives  a basic information about Nano Technology an evaluator easily rejects such submission , because he finds it as of no use instead use Nano Technology Boon for Deaf and Visually Hampered as your topic, this has a great chances of selection and it clearly shows that if you play with words then it can really impress the evaluator.
2.  List only important points don't include a bunch of theory.
3. For Abstract Submission , give a brief extract of your topic, do not forget to include strong points of your topics.
4. Try explaining things using flow charts, bars, diagrams and pictures about your research.
5. Explain judges and audience what are the new things that you have found in your topic, don't worry about the application and feasibility, as innovators are thinkers who failed several time to come out with one innovation.
6. Regular usage of postures and gestures gives your presentation and extra edge , so do follow it.
7. Don't Include unnecessary slides , instead you can add short title on slides including pictures and diagrams and leave rest of the content for speech delivery.
8.  Font Selection, colour combination and animation also plays major role in selection criteria.
9. Do not loose your confidence at any point even if stammer, as this reflects your knowledge on the topic.
10. Include regular pauses, and don't let your hands or legs shake as this shows that you are low on confidence.  
11. Always have a smile on your  face and maintain eye contact, welcome jury members, guest and students and thanks giving speech gives your presentation a catchy look.

Most of the private engineering college students wish that their papers get selected in top engineering institutes like IIT's, NITs and Deemed Universities for International Exposure, if you follow above simple steps , then it would make your journey a bit easier to get their.

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