Researchers at the University of Maryland College of Chemical and Life Sciences have developed a new technique which will improve nanofabrication, and in the same time it will make it cheaper. The advances in nanotechnology are important in manufacturing computer microchips and other tiny devices, but they are more important to create smaller structures.

In order to design structures smaller than human hair, you will need to use a technique called photolithography which requires difficult-to-use and expensive ultraviolet light. The team of researchers at the University of Maryland College of Chemical and Life Sciences led by John Fourkas, Professor of Chemistry and Biochemistry, have developed a new photolithography technique which doesn’t require ultraviolet light. The team called it RAPID, short for Resolution Augmentation through Photo-Induced Deactivation.

The well-known process of photolithography is based on light to deposit and remove materials, and create tiny patterns on surfaces. The researchers say that there is a strong link between the size created and the wavelength used so until now nanofabrication required ultraviolet light to create nanostructures.

“The RAPID lithography technique we have developed enables us to create patterns twenty times smaller than the wavelength of light employed which means that it streamlines the nanofabrication process. We expect RAPID to find many applications in areas such as electronics, optics, and biomedical devices,” said Fourkas.

Fourkas and this research group used two laser light sources of the same color – the first was used to harden the material, while the latter was used to prevent the material from hardening. The difference between the two was that the first produced only short bursts of light, while the latter was kept on perpetually. Also, the second laser light went through a custom optic which was designed to allow the sculpting of the hardened materials.

“If you have gotten a filling at the dentist in recent year, you have seen that a viscous liquid is squirted into the cavity and a blue light is then used to harden it. A similar process of hardening using light is the first element of RAPID. Now imagine that your dentist could use a second light source to sculpt the filling by preventing it from hardening in certain places. We have developed a way of using a second light source to perform this sculpting, and it allows us to create features that are 2500 times smaller than the width of a human hair. The fact that one laser is on constantly in RAPID makes this technique particularly easy to implement, because there is no need to control the timing between two different pulsed lasers,” said Fourkas.

The study is only at the beginning but Fourkas says that his team already made some important advances, and that now they are looking to improve RAPID as they want to create structures half the size of the one they created so far.

Researchers have developed world’s first nanofluidic device with complex 3D surfaces which could have enormous implications in applications like nanoscale materials processing, in pharmaceuticals, nanoparticles sorting, and it could help isolating particular DNA strands for further research studies.

The scientists from the National Institute of Standards and Technology were inspired by the manufacturing process of integrated circuits and they used it at nanoscale. The result is world’s first nanofluidic device with 3D complex surfaces called the “Lilliputian chamber” which will be used with custom-based surfaces to engineer nanoparticles among many other applications. In order to develop a nanofluidic device, researchers have to etch very small channels into a silicon wafer, just like in the manufacturing process of an integrated circuit.

So far, researchers have only managed to develop simple surfaces of only a few depths meaning that you cannot study DNA or other molecules in detail. Now, that their ability is not limited anymore, researchers will be able to study complex surfaces of nanoparticles in detail.  The manufacturing process of integrated circuits is based on “lithographic” procedures, and the researchers used them to develop complex 3D surfaces, then they designed a nanofluidic chamber which featured a staircase geometry engraved in its floor. The steps of the staircase represented a level, each increasing in depth from 10 nanometers to 620 nanometers.

In order to test their Lilliputian chamber with 3D complex surfaces, the researchers used two solutions/materials – first was based on 100-nanometer in diameter of polystyrene spheres, while the latter consisted of 20-micrometer in length DNA molecules. In the tests, the researchers introduced the solution in the deep end of the chamber, then they maneuvered the samples across the chamber using electric fields, and they tracked their movements on a microscope (the polystyrene spheres, and the DNA strands were “tagged” with fluorescent dyes to observe their movement).

The results of the tests were very convincing as when using polystyrene spheres, the so-called “size exclusion” happened when the area of the Lilliputian chamber (the channels were less than 100-nanometers in depth) remained free of the nanoparticles. When using the DNA strands, the molecules were coiled in much deeper channels, and then forced to enter in shallower channels. In other words the results clearly show that NIST’s nanofluidic device can be used to perform complex 3D operations at nanoscale.

The Lilliputian chamber could have enormous implications in various applications like scientific studies, safety invetigations, and for environmental health. The research if only at the beginning, and now the NIST researchers are looking to separate mixtures of nanoparticles, and to study DNA’s behavior in a 3D nanofluidic device.

If I learned one thing about concepts and prototypes, I learned that most of them never make it to the production line and with time they are forgotten. However, this is not the case of a prototype device created by researchers at the University of Southern California Viterbi School of Engineering. This device is a supercapacitor who usually performs electronic operations thanks to silicon chips, but the USC researchers managed to develop a transparent and flexible supercapacitor using carbon nanotubes.

The team of researchers led by Chongwu Zhou claims that the supercapacitor which uses CNT films and indium-oxide nanowires can be manufactured at prices competitive with conventional techniques which use silicon. Also, this energy storage and conversion device is completely transparent, and is so flexible that it can be “bent and twisted like a poker card.”

According to Zhou, this new capacitor features an energy density of 1.29 watt-hour per kilogram, and a storage capacitance of 64 Farad per gram, while conventional capacitors store an energy density of at most .1 watt-hour per kilogram with a specific capacitance in the range of tens of millifarads. The team consisting of aforementioned Zhou, USC post-doctorate Guozhen Shen, and USC graduate students Sawalok Sukcharoenchoke and Po-Chiang Chen, believes that their supercapacitor will have enormous implications in e-paper displays, many electronic devices, and other applications.

Zhou and his team attached indium-oxide and CNTs films on a transparent flexible substrate, then they optimized its thickness in order to preserve its flexibility and its transparency. The researchers managed to combine metal nanowires with carbon nanotubes (after many attempts) and they said that this represents the key for flexible and transparent supercapacitors as conventional storage devices are not flexible, neither transparent.

“We demonstrated enhanced specific capacitance, power density, energy density, and long operation cycles, compared to those supercapacitors made only by CNTs,” said Zhou. “We successfully produced a prototype of flexible and transparent supercapacitors built on two important nanostructured materials [including metal oxide nanowires and CNTs].”

“CNT films were fabricated by vacuum filtration method. An adhesive and flat poly (dimethysiloxane) (PDMS) stamp was adapted to peel the CNT film off of the filtration membrane and then released it onto a polyethylene terephtalate (PET) substrate. In2O3 nanowires with a diameter of ~ 20 nm and a length of ~ 5 ?m were synthesized by a pulsed laser deposition (PLD) method. The as-grown nanowires were sonicated into IPA solutions and then dispersed upon transferred CNT films to form In2O3 nanowire /CNT heterogeneous film for transparent and flexible supercapacitor study,” explained Zhou.

Well, as the researchers have demonstrated the potential of flexible and transparent supercapacitors, now we are waiting for the devices to be commercialized. Zhou said that the new supercapacitors can be manufactured at costs competitive with conventional supercapacitors and we can’t understand why the researcher didn’t mention when the devices will be available. We will have to wait for further details.

Nanotechnology has proven many times that it can be reliable and that it has enormous implications in many domains, however, researchers are looking to exploit all of its capabilities and to reach its full potential. On the other hand, researchers are also studying the human DNA to better understand the human body among others. Well, what if they could combine the two in order to get a revolutionary technique? A team of researchers at the U.S. Department of Energy from the Brookhaven National Laboratory have used DNA’s molecular assembly line to link up nanoparticles for high precision nanoconstruction.

This technique will help scientists to develop bio-sensors or better solar cells, as the DNA-like nanofabrication will probably get the best out of nanotechnology. In order to test this technique, the BNL researchers have used DNA to correlate nanoparticles in many shapes, even in 3D nanocrystals. According to the research team, the technique consists of coating the nanoparticles with strands of DNA as the segments of genetic code lead the nanoparticles to find each other, link up, and stick together in specific ways.

As the researchers were going further with their study, they used DNA-linkers to maneuver the nanoparticles and to attach them on a solid surface. Their goal was to control how the DNA-coated nanoparticles form. Although they feared that they can’t control the way nanoparticles link up, they noticed that it can be done with high precision and that the nanoconstruction technique is very predictable therefore they managed to build clusters from the nanoparticles. Please be aware that the DNA linkers were artificially built in the lab, and they “don’t code for any proteins as genes do.”

“When a particle is attached to a support surface, it cannot react with other molecules or particles in the same way as a free-floating particle,” said Oleg Gang, physicist at the Brookhaven National Laboratory, and leader of the research.

Gang says that “by controlling the number of DNA linkers and their length, we can regulate interparticle distances and a cluster’s architecture” which means that the researchers can rearrange and to create a desired construction. “Together with the high specificity of DNA interactions, this surface-anchored technique permits precise assembly of nano-objects into more complex structures,” he continued.

Also, the researchers can control and assemble the nanoparticles in very small structures. According to the researchers, they can assemble structures much smaller than 3D nanocrystals; they can put together the so-called “dimers” which are molecules consisting of two identical simpler molecules.

“When we arrange a few nanoparticles in a particular structure, new properties can emerge. Nanoparticles in this case are analogous to atoms, which, when connected in a molecule, often exhibit properties not found in the individual atoms. Our approach allows for rational and efficient assembly of nano-‘molecules.’ The properties of these new materials may be advantageous for many potential applications,” said Gang.

Aforementioned, I said that this DNA-based assembly technique for nanoparticles can lead to better solar cells. But how can it help? According to the researchers, when the nanoparticles are linked as dimers, an optical effect called plasmon resonance occurs. The plasmon resonance is a phenomenon which appears when metallic particles interact with an electromagnetic field, and as a result, it leads to a “collective oscillation” of the conductive electrons of the material. This means that engineers could eventually use the technology so that solar cells would absorb energy from the entire spectrum of light.

“The size and distance between the linked particles affect the plasmonic behavior,” explained Gang.

The study is only at the beginning and for now, the BNL researchers have applied for a patent, and they are looking to improve the technique and to see if the nanofabrication is scalable for high-throughput production. The researchers will learn more about the technique and we’re waiting to see what’s the best use for it. In the meantime, you can also check the video above and watch Gang explaining the method.

Researchers at the Georgia Institute of Technology have developed a new way to recharge electronic devices like an iPod or iPhone without the need of a battery. Their breakthrough consists of a new power source, body movements, and it was presented at the 237th National Meeting of the American Chemical Society in Salt Lake City, Utah.

According to the researchers, their technology is based on converting mechanical energy coming from body movements into electrical energy which could power electronic devices. Although this technology was designed for US Army Soldiers, it is possible to become available for the open public sometime in the future. But why for military purposes? Well, when the soldiers are far on the battlefield with no energy source, they will be able to power their devices by waving, stretching (actually, shooting down the enemy), and it will also help them cut down some of the weight of the gear.

“This research will have a major impact on defense technology, environmental monitoring, biomedical sciences and even personal electronics,” said Zhong Lin Wang, leader of the research, and Regents’ Professor, School of Material Science and Engineering at GIT.

It’s a major breakthrough as this technology can convert low frequency vibrations into electrical energy thanks to ZnO (zinc oxide) nanowires. The energy coming from body movements, the flow of the blood or even the beating of the heart will be transmitted to the devices through ZnO nanowires which can conduct electricity. The zinc oxide nanowire measures 1/5,000th and 1/25th of the human hair in length and in diameter, respectively. The advantage of the ZnO nanowires is that this material is piezoelectric meaning that it generates electrical current when put to mechanical stress.

The team of researchers called it a nanogenerator, and it’s the most efficient when it comes to low-frequency and flexible materials. Another advantage of the ZnO nanowires is that they are waterproof after they are properly and specially packaged. According to the researchers, these nanogenerators can be grown on clothing, metals, polymers, tents, and ceramics.

“Quite simply, this technology can be used to generate energy under any circumstances as long as there is movement,” said Wang.

Moreover, the technology could be useful for defense agencies in the United States as the nanogenerators could be used as nanoscale sensing devices to detect bio-terror attacks. The researchers say that the police can use it to sample air and possibly to detect harmful bio-terror agents. The advantage of the nanogenerators is that they don’t need batteries, unlike biosensors that are implanted under the skin and still need batteries.

The study is only at the beginning, but it looks promising as it can provide electricity continuosly. However, the GIT researchers are now looking to increase the power and the output voltage, and other aspects of the nanogenerators. As an offbeat topic, we have to inform you that this research was funded by DARPA, DoE, NSF, and the National Institute of Health. Also, we have to remind you that the nanogenerators will be available only for the US Army in the early stages of the development so you should enrol yourself if you want limitless energy for your devices.

I’ve said it many times – nanotechnology is the future. Scientists at the Maryland NanoCenter from the University of Maryland have designed batteries that store energy coming from renewable sources, and which are 10 times more efficient than conventional systems. If you own a hybrid car or if you have solar panels on your roof, then you probably know that the systems which store the power are now very efficient, as you cannot drive long distances, while solar power deliver energy only a part of the day.

The devices that store power from alternative sources are very expensive and inefficient, but this could change in the near future thanks to the research made by the researchers at the University of Maryland.

“Renewable energy sources like solar and wind provide time-varying, somewhat unpredictable energy supply, which must be captured and stored as electrical energy until demanded. Conventional devices to store and deliver electrical energy — batteries and capacitors — cannot achieve the needed combination of high energy density, high power, and fast recharge that are essential for our energy future,” said Gary Rubloff, director of the University of Maryland’s NanoCenter.

The new energy storage devices are based on nanotechnology and they consist of millions of identical nanostructures which were shaped to transport power very fast to the storage surface. The team led by Professor Rubloff and his collaborator, Professor Sang Bok Lee, said that materials act according to the laws of nature, however, they have exploited unusual behaviors of these materials like self-assembly, self-limiting reaction, and self-alignment, and they have created millions of identical nanostructures which receive, store, and deliver electrical power.

“These devices exploit unique combinations of materials, processes, and structures to optimize both energy and power density – combinations that, taken together, have real promise for building a viable next-generation technology, and around it, a vital new sector of the tech economy. The goal for electrical energy storage systems is to simultaneously achieve high power and high energy density to enable the devices to hold large amounts of energy, to deliver that energy at high power, and to recharge rapidly,” said Rubloff.

Energy storage devices are divided in three categories – batteries (most based on lithium-ion) which store a lot of energy, but do not deliver high power and they cannot be recharged quickly; electrochemical capacitors which deliver high power at the price of lower energy density; electrostatic capacitors which deliver high power and can be recharged quickly at the price of lower energy density.

Now, the energy storage devices that the Maryland researchers have developed are called electrostatic nanocapacitors which deliver high power, can be recharge quickly, but they increase the energy density, and according to the team of researchers, these new storage devices are ten times better than conventional devices available on the market.

The nanotech batteries will get improvements soon, and Professors Lee and Rubloff expect them to enter in mass production shortly, and soon we could see them as storage devices for solar panel system and inside a hybrid car battery. Also, on the long run we could see nanotechnology as the “new energy capture technology” and it could be fully-integrated with energy storage devices. Well, ten times more power sounds great, now we just have to wait for the nanotech batteries to be perfected.

The tendency in electronic devices is all about getting smaller and smaller and smaller. It’s just the way these things need to be. However, they also have to be very efficient and we have nanotechnology and carbon nanotubes to make them like this. In order to develop smaller and more efficient electronics, scientists want to develop the next generation of devices based on carbon nanotubes using a technique called “chemical vapor deposition”, but it’s very hard to manipulate these structures and to bring them to a useful state.

A new vision is needed to complete the next-gen electronics and thanks to a breakthrough from scientists at the University of Nebraska-Lincoln, our future devices could be built from carbon nanotubes. The team of scientists led by professor Yongfeng Lu and postdoctoral researcher Yunshen Zhou, used a technique based on the so-called “optical near-field effects” and they managed to control the growth of carbon nanotubes. The researchers linked individually self-aligned carbon nanotubes with sharp-tipped electrodes, a process which is very different from previous techniques where the carbon nanotubes were manipulated after growth.

“With our method, there’s no requirement for expensive instrumentation and no requirement for tedious processes. It’s a one-step process. We call it ’self-aligning growth.’ The carbon nanotubes ‘know’ where to start growth. In previous efforts, they could only manipulate carbon nanotubes one piece at a time, so they had to align the carbon nanotubes one by one. For our approach using optical near-field effects, all locations with sharp tips can accommodate carbon nanotube growth. That means we can make multiple carbon nanotubes at a time and all of them will be self-aligned,” said professor Lu.

Although the researchers didn’t manage to generate millions of self-aligned carbon nanotubes, for the time being this is quite a breakthrough and you will have to take into consideration the fact that this is only the beginning therefore in a few years Lu and his team could develop and commercialize nanoscale devices like bio-sensors, photon-sensors, memory cells, or light-emitters.

“We have shown that we can use optical near-field effects to control growth for a small amount of carbon nanotubes. We want to make this process scalable so it can be used to make large numbers at a time so we can make a circuit or a system by this approach,” concluded professor Lu.

When I first heard about nanotechnology, I knew that nanoscale components will be revolutionary and that they will not have any real competitor for a long time although for the moment this technique is not exploited at full potential. A team of scientists from the University of California, Berkeley in collaboration with fellow scientists from the University of Massachusetts Amhert have developed a new way to increase the storage capacity of electronics.

This new technology is based on self-assembling nanoscale elements and according to Ting Xu, co-author of the study from the Lawrence Berkeley National Laboratory, “the density achievable with the technology we’ve developed could potentially enable the contents of 250 DVDs to fit onto a surface the size of a quarter.”

In other words this is pretty impressive as the scientists manage to develop nanoscale elements that can hold data of 10 TBs / square inch (which means 125 GB of data  per square inch). Also, Thomas Russel, scientist at the University of Massachusetts Amherst, added that they “can generate nearly perfect arrays over macroscopic surfaces where the density is over 15 times higher than anything achieved before, with that order of density, one could get a high-definition picture on a screen the size of a JumboTron.”

Imagine the enormous implications of this technology. Just think that this is only the beginning, and according to Mr. Xu “technique is more environmentally friendly than photolithography, which requires the use of harsh chemicals and acids.”

Press Release ]]> http://deviceace.com/science/119/scientists-develop-nanotechnology-which-holds-10tbs-per-square-inch.html/feed 4