Ocean Proof Mobile Phones Through Atomic Layer Deposition and Barrier Films

Scientists have developed a barrier film through through a molecular process called atomic layer deposition (ALD) that can protect objects such as mobile phones from harsh environments such as salt water.

Barrier films are used to protect electronics from water vapor, oxygen degradation, and other harmful elements. Current barrier films although offer protection, the way they are made still result in small impurities and imperfections that can still allow water or oxygen to penetrate.

Using atomic layer deposition, the barrier film is controlled at the molecular level. The process results in an even coating without any holes or impurities that may be penetrated by harmful elements. The finished product is about 10 nanometers thick which is hundreds of times thinner than current available high end barrier films.

By using this process, electronic devices using organic materials such as OLED displays can be developed that last longer. ALso, existing electronic devices such as mobile phones, implantable biomedical devices, and solar power cells can be produced which can operate in extreme conditions.

FLUENCE (Fluid-Enhanced Crystal Engineering) Process Results in 10 Times More Efficient Organic Electronics

A single-crystal organic semiconductor array that is 1mm by 20mm. The neatly-aligned blue strips are what provide greater electric charge mobility. The Stanford logo shown here is the same size as a dime.

A new printing process called FLUENCE (Fluid-Enhanced Crystal Engineering) can generate organic electronic materials that are ten times more conductive than those currently available.

Organic electronics are materials that utilize carbon-based polymers and molecules to build electronic conductors and resistors. Instead of using inorganic materials such as copper and silicon, organic electronics are produced by printing out the material on inexpensive polymeric substrates like polyethylene terephtalate (PET) or polycarbonate (PC) that are cheaper than conventional inorganic components.

Ink jet printers or coating equipment (like those used to produce photographic film) can also be used to print out electronic components one on top of another to produce smaller more compact semiconductors.

Organic electronic products are thin, lightweight, and flexible. These properties have been proven effective in the modern application of electronic devices and gadgets such as touch sensors, display screens, and in solar cells. In solar cells, solar sheeting that are thin and translucent (similar to a plastic sheet) are products of organic electronics. Display screens such as OLED (Organic LED)screens are now used widely in the smartphone and tablet market.

High Speed Bistable Graphene Transistor Being Developed

Graphene transistor

A graphene transistor exhibiting bistable characteristics in which charge-carrying electrons move at incredible speeds of up to trillions of switches per second has been developed.

Graphene has been touted as the wonder material with uses ranging from conductors, transistors, and even as a material for batteries.

Graphene is a better conductor for electricity than silicon and conducts heat better than copper. It is almost invisible since it is only one atom thick and is flexible, allowing it to be molded into different shapes. Graphene is also as strong as a diamond.

Just like graphene, diamonds are also made up of carbon atoms. Carbon atoms in a diamond are interconnected with four strong atomic bonds. With graphene, the carbon atoms are interconnected in three strong atomic bonds. But unlike diamonds, graphene is not rare. Graphene comes from graphite, the material used for pencil lead. Graphite is actually layers of graphene that are connected together with a weak atomic bond.

Graphene can be applied to a substrate like plastic foil, where it can be used in electronic devices that are flexible, energy efficient, and faster than conventional silicon based transistors. Graphene can transmit ten times more data than silicon.

Graphene Shows Potential To Be Efficient Photovoltaic Material In Light Detection and Energy Harvest

Graphene research has shown that the material can be used in the development of efficient solar photovoltaic cells.

Much has been written and discussed about graphene. It has opened up a whole litany of advanced applications that it has been described as "The Wonder Material".

One particular property of graphene that many scientists have been focusing on is how electrons behave and interact with graphene. Graphene, being only one atom thick, allows electron to move much more freely along its surface. The electrons travel through the graphene sheet as if they carry no mass, as fast as just one hundredth that of the speed of light. This makes graphene a great conductor, better than even copper.

Also, since graphene is just one atom thick, diodes, transistors, and other electronic components can be developed on a single-layered device architecture. By using nano-scale electronic channels and tailoring the geometrical symmetry, devices can be operated on at very high speeds of up to 1.5 Terahertz (1,500 GHz). This allows for the development of high speed electronics for various applications and devices.

Researchers have discovered a new property of graphene that allows it to convert a single absorbed photon into multiple electrons. This could open up research into the development of efficient solar cells.

Organic Ferroelectric Molecule Developed As An Alternative To Silicon For Semiconductors

Electrical response overlaid on the newly characterized organic molecular crystal.
Credit: Jiangyu Li, University of Washington

Diisopropylammonium bromide is a new organic molecule synthesized from bromine, carbon, hydrogen and nitrogen that may be an alternative to silicon for use in semiconductors and other memory, sensing and low-cost energy storage applications.

Organic molecules are molecules that contain carbon. Carbon is a versatile atom and can attach easily to other atoms (forming 4 covalent bonds). The science of designing, synthesizing, characterizing, and developing applications for molecules that contain carbon is called organic chemistry.

Organic molecules are often associated with living things but for organic compounds this is not necessarily the case. The term comes from the old belief that certain compounds and molecules require a "life-force" of a living thing to be generated. The belief has been discredited but the term still remains.

Organic chemistry applications range from the medical to the industrial. One role of organic chemists is to synthesize and develop new molecules that will address a problem or enhance a product.

Synthetic organic compounds usually carry properties that enhance a process, mitigate or address a design/process flaw, or solve a problem. Most of these applications can be seen in pharmaceutical and consumer products.

Warm White LED Lamp Using Single Yellow Phosphor Ideal For Indoor Lighting Developed

A warm white LED has been developed by scientists using a single yellow phosphor. This is ideal for indoor lighting as it doesn't give out the usual bright white-blue light current LED lamps do.

Low energy lighting options can be found almost anywhere these days. The two most common are Compact Fluorescent Lamps (CFL) and LED lamps. A 9 watt CFL lighting fixture has an equivalent brightness as that of a regular 45 watt incandescent lamp. An 11 watt CFL is equal to 60 watts and an 18/20 watt lamp will give an equivalent incandescent brightness of 100 watts. They also last 10 to 15 times longer than a regular light bulb, around 15,000 hours. A regular light bulb lasts around 1500 to 2000 hours.

A newer form of low energy lighting is the LED (Light Emitting Diode) lamp. It is a form of solid state lighting. Solid state devices are devices built form solid materials where electrons are are confined entirely within the solid material.

LED lamps can give out light equivalent to a 50 watt halogen lamp at a fraction of the energy needed (around 7 watts). An LED lamp also has a lifespan of around 30,000 to 50,000 hours; twice that of a CFL light bulb. One year has 8,760 hours.

At an average daily use of 5 hours a day, an LED bulb would last around 16 years.

LED bulbs are still more expensive than other available lighting options. But in the long term, the energy savings will compensate for it.

The problem with LED lamps is the color temperature that it gives out. The light of the LED has a bluish white tinge that some people find unsettling.

MIT News: Bending Light To Cloak Objects Lead To Better Electron Transfer For Thermoelectric Devices

A new approach that allows objects to become “invisible” has now been applied to an entirely different area: letting particles “hide” from passing electrons, which could lead to more efficient thermoelectric devices and new kinds of electronics.

Diagram shows the 'probability flux' of electrons, a representation of the paths of electrons as they pass through an 'invisible' nanoparticle. While the paths are bent as they enter the particle, they are subsequently bent back so that they re-emerge from the other side on the same trajectory they started with — just as if the particle wasn't there.
Image courtesy Bolin Liao et al.

The concept — developed by MIT graduate student Bolin Liao, former postdoc Mona Zebarjadi (now an assistant professor at Rutgers University), research scientist Keivan Esfarjani, and mechanical engineering professor Gang Chen — is described in a paper in the journal Physical Review Letters.

Graphene Roadmap Developed To Showcase Potential of the Wonder Material

The best thing that can define the dawn of 21st century science is the discovery of graphene. Graphene is a material that possesses a myriad of amazing properties that can be utilized in over a dozen fields of science and technology.

Graphene is a one atom thick sheet of carbon atoms, each interconnected with three strong atomic bonds. The resulting hexagonal structure resembles a honeycombed chicken wire. Being one-atom thick, graphene is just around 0.33 nanometers tall, that's around one million times thinner than a strand of hair.

Despite its thickness, graphene is the strongest material found on Earth.

Diamonds are also made up of carbon atoms, each interconnected with four strong atomic bonds. But unlike diamonds, graphene is not rare. Graphene comes from graphite, the material used for pencil lead. Graphite is actually layers of graphene that are connected together with a weak atomic bond.

In fact, Andre Geim and Kostya Novoselov, first isolated Graphene by using ordinary masking tape to peel off a layer of graphene from graphite. This can be done because of the weak bond connecting the graphene layers together. By constantly stripping away at the peeled off graphite, they managed to extract a single atom layer of graphene. Because of their discovery, they were awarded the Nobel Prize in 2010.

Graphene can be used in many practical applications.

• Graphene is a great conductor of electricity. Electrons passes through graphene at almost the speed of light.
• Graphene is conducts heat efficiently. Its high thermal conductivity can be used to dissipate heat efficiently in electronic devices.
• Graphene is harder than a diamond and 300 times harder than steel. This property can be utilized in developing composite materials that can be used in a wide range of applications like construction.
• Despite being one atom thick, Graphene also absorbs enough light to be visible to the naked eye. Because graphene absorbs around 2.3% of light, graphene can also be utilized for optical applications
• Graphene can adsorb and desorb atoms. Adsorption is the ability to gather substances into its surface. Not to be confused with absorption where the substance permeates into the structure. This property is extremely useful in chemical applications
• Graphene is an inert material. Despite it being only one atom thick makes it exposed to the environment, graphene is a non-reactive material

Bio Nanotech Transient Electronics For Medical and Commercial Use Dissolve After Completing Its Task

New biocompatible electronic devices, encapsulated in silk, can dissolve harmlessly into their surroundings after a precise amount of time. These "transient electronics" promise medical implants that never need surgical removal, as well as environmental monitors and consumer electronics that can become compost rather than trash. Here, a biodegradable integrated circuit -- including transistors, diodes, inductors and capacitors-- is partially dissolved by a droplet of water. The image is courtesy of Tufts University and the University of Illinois.
Credit: Photo credit: Fiorenzo Omenetto/Tufts University

In the 1966 movie, Fantastic Voyage, a crew of five was reduced to microscopic size and injected into a human body. Their goal was to repair a blood clot in the brain and leave before they all revert back to their original size. Almost fifty years later, nanotechnology as the movie has shown, may be the next step forward not only in medical procedures but commercial and industrial applications as well.

Aside from stem cell research, nanotechnology is gaining wide popularity in medical and scientific research. Implants and devices are being developed, hundreds of times smaller than the width of a human hair, that can perform surgery, deliver medication, and even eradicate cancer cells. Because of its microscopic size, bionanotech devices are non-invasive and results in fewer complications normal open surgery would have.

This technology can be used to develop medical devices for surgical purposes as well as for drug delivery and monitoring purposes too. There have been studies in developing devices that monitor and repair blood vessels for stroke inducing plaque and other harmful substances. Even often used tools such as surgical gloves can be integrated with nanotechnology to enhance and improve its use and function.

In Fantastic Voyage, the movie addressed a problem that up until now is an obstacle when it comes to bionanotechnology; what to do with a bionanodevice after it has completed its task. And now, scientists have come up with an ingenious method to address this problem; electronics that dissolve.

Smooth as silk 'transient electronics' dissolve in body or environment

Tiny, fully biocompatible electronic devices that are able to dissolve harmlessly into their surroundings after functioning for a precise amount of time have been created by a research team led by biomedical engineers at Tufts University in collaboration with researchers at the University of Illinois at Urbana-Champaign.

Dubbed "transient electronics," the new class of silk-silicon devices promises a generation of medical implants that never need surgical removal, as well as environmental monitors and consumer electronics that can become compost rather than trash.

Magnetic Topological Insulator Eliminate Loss In Electrical Power Transmission

This is a depiction of the quantum Hall effect (left) and the quantum anomalous Hall effect (right).
Credit: RIKEN

The quantum Hall effect (QHE) describes the quantized transport in two dimensional electron gases placed in a transverse magnetic field: the longitudinal resistance vanishes while the Hall resistance is quantized to a rational multiple of h/e2.

The effect was discovered in 1879 by Edwin Hall. But since the electron has not yet been experimentally discovered, application and understanding of the effect had to wait.

In 1985, Klaus von Klitzing won the Noble Prize in Physics for discovering that the Hall conductivity was exactly quantized. This phenomenon, referred to as "exact quantization", has allowed for the definition of a new practical standard for electrical resistance.

The quantum Hall effect also provides an extremely precise independent determination of the fine structure constant, a quantity of fundamental importance in quantum electrodynamics.

A new route to dissipationless electronics

Realization of a new type of magnetic phase in devices opens the door to electronics based on topologically non-trivial materials

A team of researchers at RIKEN and the University of Tokyo has demonstrated a new material that promises to eliminate loss in electrical power transmission. The surprise is that their methodology for solving this classic energy problem is based upon the first realization of a highly exotic type of magnetic semiconductor first theorized less than a decade ago - a magnetic topological insulator.

Development of energy saving technologies is one of the central pursuits of modern science. From advancing alternative energy resources like wind and solar power to improving the infrastructure of the electrical power grid, this pursuit by scientists and engineers takes on a variety of forms. One focus in recent years has been eliminating energy loss in the transmission of power itself, which by some estimates consumes more than 10% of all energy being produced. The research team has demonstrated a new material - a magnetic topological insulator - that can eliminate this loss.

World Smallest Semiconductor Laser - Breakthrough in Photonic Technology

Semiconductor lasers are eyed to be the next generation in laser technology. These lasters are compact, can be mass produced, easily integrated into applications, their properties are being improved constantly, they are becoming more and more powerful and efficient and they have found a widespread use as pumps for solid–state lasers.

The active medium of the laser is a semiconductor. This is similar to the ones found in an LED. The most common of this is formed from a p-n junction and powered by injected electric current. The former devices are sometimes referred to as injection laser diodes to distinguish them from optically pumped laser diodes.

The majority of the materials used by the semiconductor are based on a combination of elements in the third group of the Periodic Table (Aluminum (Al), Gallium (Ga), Indium (In)) and the fifth group (Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb)). This group of elements are referred to as the III-V compounds. Examples include GaAs, AlGaAs, InGaAs and InGaAsP alloys. The cw laser emission wavelengths are normally within 630~1600 nm, but recently InGaN semiconductor lasers were found to generate cw 410 nm blue light at room temperature. The semiconductor lasers that can generate blue-green light uses materials which are the combination of elements of the second group (Cadmium (Cd) and Zinc (Zn)) and the sixth group (Sulfur (S), Selenium (SE)).

This is an illustration of the nanoscale semiconductor structure used for demonstrating the ultra-low-threshold nanolaser. A single nanorod is placed on a thin silver film (28 nm thick). The resonant electromagnetic field is concentrated at the 5-nm-thick silicon dioxide gap layer sandwiched by the semiconductor nanorod and the atomically smooth silver film.
Credit: (c)Science

World's smallest semiconductor laser created by University of Texas scientists

Physicists at The University of Texas at Austin, in collaboration with colleagues in Taiwan, have developed the world's smallest semiconductor laser, a breakthrough for emerging photonic technology with applications from computing to medicine.

The scientists report their efforts in this week's Science.

Miniaturization of semiconductor lasers is key for the development of faster, smaller and lower energy photon-based technologies, such as ultrafast computer chips; highly sensitive biosensors for detecting, treating and studying disease; and next-generation communication technologies.

Such photonic devices could use nanolasers to generate optical signals and transmit information, and have the potential to replace electronic circuits. But the size and performance of photonic devices have been restricted by what's known as the three-dimensional optical diffraction limit.

Spin Seebeck Effect Lead To Engines With No Moving Parts And Infinitely Reliable

Schematic illustration of the spin-Seebeck effects
Credit: Tohoku University

The Seebeck effect is a phenomenon in which a temperature difference between two dissimilar electrical conductors or semiconductors produces a voltage difference between the two substances. It is simply the conversion of the temperature differences directly into electricity.

This effect is named for German-Estonian physicist Thomas Johann Seebeck who discovered it in 1821.

Physicists in 2008, discovered what they are calling the spin Seebeck effect. The spin Seebeck effect is seen when heat is applied to a magnetized metal. As a result, electrons rearrange themselves according to their spin. Unlike ordinary electron movement, this rearrangement does not create heat as a waste product.

This development can lead to the manufacturing of faster, more efficient microchips and open up a new class of devices called spintonics devices.

Researchers 1 step closer to new kind of thermoelectric 'heat engine'

Researchers who are studying a new magnetic effect that converts heat to electricity have discovered how to amplify it a thousand times over - a first step in making the technology more practical.

In the so-called spin Seebeck effect, the spin of electrons creates a current in magnetic materials, which is detected as a voltage in an adjacent metal. Ohio State University researchers have figured out how to create a similar effect in a non-magnetic semiconductor while producing more electrical power.

They've named the amplified effect the "giant spin-Seebeck" effect, and the university will license patent-pending variations of the technology.

The resulting voltages are admittedly tiny, but in this week's issue of the journal Nature, the researchers report boosting the amount of voltage produced per degree of temperature change inside the semiconductor from a few microvolts to a few millivolts - a 1,000-fold increase in voltage, producing a 1-million-fold increase in power.

Nanotechnology And Vacuum Tube Technology For Faster And More Efficient Electronics

A vacuum tube is simply a sealed glass tube or container. The inside of the tube is a space that is empty of any matter or gas; a vacuum. The vacuum tube is a device that controls the current through the vacuum. Vacuum tubes are used for rectification, amplification, switching, or creation of electrical signals.

Thomas Edison discovered this when experimenting with light bulbs. He discovered that when an electric contacts are introduced to both ends, the current jumps from the hot filament of the bulb to a metal plate at the bottom. This is called the Edison Effect.

The Edison Effect or Thermal Electron Emission basically says that electric current can travel through a gas or a vacuum without the need of an electric wire to move through.

The vacuum tube found its use in 1904 when John A. Fleming invented the Diode. A diode is the most simple vacuum tube. It is basically a light bulb with an electrode inside it. The diode works when the bulb's filament is heated white hot and electrons are boiled off its surface and into the vacuum inside the bulb. If the extra electrode is made more positive than the hot filament, a direct current flows through the vacuum to the anode.

Diode

The diode acted like a valve (and it was known as such) because the current in the tube travels exclusively in one direction. This turned out critical for radio sets then since it needed to turn alternating current into direct current, which the diode does.

Lee De Forest followed with his invention of the Audion. This type of vacuum tube performs like a diode but additionally also increases the current along the way. This is done by placing a metal grid in the middle of the vacuum and using a small input current to change the voltage on the grid. An audion can control the flow of the second more powerful current through the tube. The strength of the two currents need not to be related; a weak current can be applied to the tube's grid while a much stronger one can come out the main electrodes of the tube.

Triode

The audion soon led to the Triode. A triode is an three electrode version of the Audion. The triode is basically the first electronic amplifier, It served as an electronic amplifier in radio communications. This revolutionized the production of radio transmitters and receivers. It also led the great improvements to the telephone system in the US.

The invention of the triode ushered in the Electronic Revolution of the 20th century.

Smaller, cheaper, efficient and reliable solid state semiconductor devices such as transistors and solid state diodes have replaced vacuum tubes in modern devices. But some applications still need the use of vacuum tubes such as High Power Radio Frequency Transmitters and Microwave Ovens.

In the music industry, professional musicians still prefer vacuum tube based sound amplifiers because of the quality of sound it produces.

Pitt researchers propose new spin on old method to develop more efficient electronics

With the advent of semiconductor transistors—invented in 1947 as a replacement for bulky and inefficient vacuum tubes—has come the consistent demand for faster, more energy-efficient technologies. To fill this need, researchers at the University of Pittsburgh are proposing a new spin on an old method: a switch from the use of silicon electronics back to vacuums as a medium for electron transport—exhibiting a significant paradigm shift in electronics. Their findings were published online in Nature Nanotechnology July 1.

For the past 40 years, the number of transistors placed on integrated circuit boards in devices like computers and smartphones has doubled every two years, producing faster and more efficient machines. This doubling effect, commonly known as "Moore's Law," occurred by scientists' ability to continually shrink the transistor size, thus producing computer chips with all-around better performance. However, as transistor sizes have approached lower nanometer scales, it's become increasingly difficult and expensive to extend Moore's Law further.