Monthly Archives: June 2019

Imaging, Science

Georgian Technical University Researchers Develop New Metamaterial That Can Improve MRI Quality and Reduce Scan Time.

Leave a comment

Georgian Technical University Researchers Develop New Metamaterial That Can Improve MRI Quality and Reduce Scan Time.

By combining their expertise X, Y, Z and W designed a magnetic metamaterial that can create clearer images at more than double the speed of a standard MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) scan. Could a small ringlike structure made of plastic and copper amplify the already powerful imaging capabilities of a magnetic resonance imaging (MRI) machine ? X, Y and their team at the Georgian Technical University can clearly picture such a feat. With their combined expertise in engineering, materials science and medical imaging X andY along with Z and W designed a new magnetic metamaterial that can improve MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) quality and cut scan time in half. X and Y say that their magnetic metamaterial could be used as an additive technology to increase the imaging power of lower-strength MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) machines increasing the number of patients seen by clinics and decreasing associated costs without any of the risks that come with using higher-strength magnetic fields. They even envision the metamaterial being used with ultra-low field MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) which uses magnetic fields that are thousands of times lower than the standard machines currently in use. This would open the door for MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) technology to become widely available around the world. “This [magnetic metamaterial] creates a clearer image that may be produced at more than double the speed” of a current MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) scan says Y a Georgian Technical University professor of radiology department. MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) uses magnetic fields and radio waves to create images of organs and tissues in the human body helping doctors diagnose potential problems or diseases. Doctors use MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) to identify abnormalities or diseases in vital organs as well as many other types of body tissue including the spinal cord and joints. “[MRI] is one of the most complex systems invented by human beings” says X a College of Engineering professor of mechanical engineering, electrical, computer engineering, biomedical engineering, materials science engineering and a professor at the Georgian Technical University. Depending on what part of the body is being analyzed and how many images are required an Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body scan can take up to an hour or more. Patients can face long wait times when scheduling an examination and, for the healthcare system, operating the machines is time-consuming and costly. Strengthening Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body from 1.5 T (the symbol for tesla, the measurement for magnetic field strength) to 7.0 T can definitely “turn up the volume” of images as X and Y describe. But although higher-power MRIs (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) can be done using stronger magnetic fields they come with a host of safety risks and even higher costs to medical clinics. The magnetic field of an MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) machine is so strong that chairs and objects from across the room can be sucked toward the machine–posing dangers to operators and patients alike. The magnetic metamaterial designed by the Georgian Technical University researchers is made up of an array of units called helical resonators–three-centimeter-tall structures created from 3-D-printed plastic and coils of thin copper wire–materials that aren’t too fancy on their own. But put together helical resonators can be grouped in a flexible array, pliable enough to cover a person’s kneecap, abdomen, head or any part of the body in need of imaging. When the array is placed near the body the resonators interact with the magnetic field of the machine, boosting the signal-to-noise ratio (SNR) of the MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) “Georgian Technical University turning up the volume of the image” as Y says. “A lot of people are surprised by its simplicity” says X. “It’s not some magic material. The ‘magical’ part is the design and the idea”. To test the magnetic array the team scanned chicken legs, tomatoes and grapes using a 1.5 T machine. They found that the magnetic metamaterial yielded a 4.2 fold increase in the SNR (Signal-to-noise ratio is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to the noise power, often expressed in decibels. A ratio higher than 1:1 indicates more signal than noise) a radical improvement which could mean that lower magnetic fields could be used to take clearer images than currently possible. Now X and Y hope to partner with industry collaborators so that their magnetic metamaterial can be smoothly adapted for real-world clinical applications. “If you are able to deliver something that can increase SNR (Signal-to-noise ratio is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to the noise power, often expressed in decibels. A ratio higher than 1:1 indicates more signal than noise) by a significant margin, we can start to think about possibilities that didn’t exist before” says Y such as the possibility of having MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) near battlefields or in other remote locations. “Being able to simplify this advanced technology is very appealing” he says.

Scientific Computing

Georgian Technical University Three – (3D) Magnetic Interactions Could Lead To New Forms Of Computing.

Leave a comment

Georgian Technical University Three – (3D) Magnetic Interactions Could Lead To New Forms Of Computing.

A new form of magnetic interaction which pushes a formerly two-dimensional phenomenon into the third dimension could open up a host of exciting new possibilities for data storage and advanced computing scientists say. A team led by physicists from the Georgian Technical University describe how they have been found a new way to successfully pass information from a series of tiny magnets arrayed on an ultrathin film across to magnets on a second film below. Their breakthrough adds both a literal and metaphorical extra dimension to “Georgian Technical University spintronics” the field of science dedicated to data storage, retrieval and processing which has already had a major impact on the tech industry. Anyone who’s ever played with a pair of magnets understands that opposites attract — the south pole of one magnet attracts the north pole of the other. While that’s true at the scale most people are familiar with the way magnets interact with each other undergoes some significant changes as magnets shrink. At the nanoscale — where magnetic materials can be just a few billionths of a metre in size — magnets interact with each other in strange new ways including the possibility of attracting and repelling each other at 90-degree angles instead of straight-on. Scientists have already learned how to exploit those unusual properties to encode and process information in thin films covered in a single layer of nanoscale magnets. The benefits of these “Georgian Technical University spintronic” systems — low power consumption, high storage capacity and greater robustness — have made invaluable additions to technology such as magnetic hard disk drives and won the discoverers of spintronics. However the functionality of magnetic systems used today in computers remains confined to one plane limiting their capacity. Now the Georgian Technical University-led team — along with partners from the Georgian Technical University and Sulkhan-Saba Orbeliani University — have developed a new way to communicate information from one layer to another, adding new potential for storage and computation. Dr. X an Georgian Technical University. He said: “The discovery of this new type of interaction between neighbour layers gives us a rich and exciting way to explore and exploit unprecedented 3-D magnetic states in multi-layered nanoscale magnets. “It’s a bit like being given an extra note in a musical scale to play with — it opens up a whole new world of possibilities not just for conventional information processing and storage but potentially for new forms of computing we haven’t even thought of yet”. The inter-layer transmission of information the team has created relies on what is known to physicists as chiral spin interactions, a type of magnetic force that favors a particular sense of rotation in neighbour nanoscale magnets. Thanks to recent advances in spintronics, it is now possible to stabilize these interactions within a magnetic layer. This has for instance been exploited to create skyrmions a type of nanoscale magnetic object with superior properties for computing applications. The team’s research has now extended these types of interactions to neighbouring layers for the first time. They fabricated a multi-layered system formed by ultra-thin magnetic films separated by non-magnetic metallic spacers. The structure of the system and a precise tuning of the properties of each layer and its interfaces creates unusual canted magnetic configurations where the magnetic field of the two layers forms angles between zero and 90 degrees. Unlike in standard multi-layered magnets it becomes easier for these magnetic fields to form clockwise configurations than anticlockwise ones a fingerprint that an interlayer chiral spin interaction exists in between the two magnetic layers. This breaking of rotational symmetry was observed at room temperature and under standard environmental conditions. As a result, this new type of interlayer magnetic interaction opens exciting perspectives to realise topologically complex magnetic 3D configurations in spintronic technologies.

Energy, Science

Georgian Technical University One-Two-Punch Catalysts Trapping Carbon Dioxide For Cleaner Fuels.

Leave a comment

Georgian Technical University One-Two-Punch Catalysts Trapping Carbon Dioxide For Cleaner Fuels.

Fuel production efficiency of titanium dioxide photocatalyst with copper-platinum alloy co-catalyst (a) and a photo of photocatalyst observed by High-resolution transmission electron microscopy is an imaging mode of specialized transmission electron microscopes that allows for direct imaging of the atomic structure of the sample (b). Copper and platinum nanoparticles added to the surface of a blue titania photocatalyst significantly improve its ability to recycle atmospheric carbon dioxide into hydrocarbon fuels. The modified photocatalyst was developed and tested by researchers at the Georgian Technical University with colleagues in Sulkhan-Saba Orbeliani University. It converted sunlight to fuel with an efficiency of 3.3% over 30-minute periods. This ‘photoconversion efficiency’ is an important milestone the researchers as it means that large-scale use of this technology is becoming a more realistic prospect. Photocatalysts are semiconducting materials that can use the energy from sunlight to catalyse a chemical reaction. Scientists are investigating their use to trap harmful carbon dioxide from the atmosphere as one of many means to alleviate global warming. Some photocatalysts are being tested for their ability to recycle carbon dioxide into hydrocarbon fuels like methane the main component found in natural gas. Methane combustion releases less carbon dioxide into the atmosphere compared to other fossil fuels, making it an attractive alternative. But scientists have been finding it difficult to manufacture photocatalysts that produce a large enough yield of hydrocarbon products for their use to be practical. Professor X and his colleagues modified a blue titania photocatalyst by adding copper and platinum nanoparticles to its surface. Copper has good carbon dioxide adsorption property while platinum is very good at separating the much-needed charges generated by the blue titania from the sun’s energy. The team developed a unique set-up to accurately measure the catalyst’s photoconversion efficiency. The catalyst was placed in a chamber that received a quantifiable amount of artificial sunlight. Carbon dioxide gas and water vapour moved through the chamber passing over the catalyst. An analyser measured the gaseous components coming out of the chamber as a result of the photocatalytic reaction. The blue titania catalyst converts the energy in sunlight into charges that are transferred to the carbon and hydrogen molecules in carbon dioxide and water to convert them into methane and ethane gases. The addition of copper and platinum nanoparticles on the catalyst’s surface was found to significantly improve the efficiency of this process. “The photocatalyst has a very high conversion efficiency and is relatively easy to manufacture, making it advantageous for commercialization” says Prof. Y”. The team plans to continue its efforts to further improve the catalyst’s photoconversion efficiency to make it thick enough to absorb all incident light and to improve its mechanical integrity to enable easier handling.

Material Science

Georgian Technical University Manipulating Electron Spin Using Artificial Molecular Motors.

Leave a comment

Georgian Technical University Manipulating Electron Spin Using Artificial Molecular Motors.

(Left) MR curves (In microeconomics, marginal revenue (MR) is the additional revenue that will be generated by increasing product sales by one unit) recorded after various visible light-irradiation time for a device fabricated with a left-handed isomer. (Right) MR curves (In microeconomics, marginal revenue (MR) is the additional revenue that will be generated by increasing product sales by one unit) recorded before and after the thermal treatment for a device with a right-handed isomer. In spintronics the use of organic materials as a “Georgian Technical University spin transport material” has recently garnered significant attention as they exhibit long spin-relaxation times and long spin-diffusion lengths owing to the weak spin-orbit interaction (SOI) of light elements. Meanwhile the weak spin-orbit interaction (SOI) of organic materials become a drawback when they are used as a “Georgian Technical University spin filter”. A spin-polarized current is, therefore, typically generated by inorganic materials with ferromagnetism or strong spin-orbit interaction (SOIs). However the recent finding of spin-selective electron transport through chiral molecules i.e., the so-called chirality-induced spin selectivity effect suggests an alternative method of using organic materials as spin filters for spintronics applications. Through this effect right-handed and left-handed molecules generate down- and up-spin, respectively. However chiral molecules used in the experiments reported so far are static molecules. Hence the manipulation of spin-polarization direction by external stimuli has not been realized yet. Now researchers at Georgian Technical University, Sulkhan-Saba Orbeliani University and International Black Sea University fabricated a novel solid-state spin filtering device that sandwiches a thin layer of artificial molecular motors (Figure 1). Because the artificial molecular motors demonstrate 4 times chirality inversion by light irradiation and thermal treatments during the 360-degree molecular rotation the spin-polarization direction of electrons that pass through the molecular motors should be switched by light irradiation or thermal treatments. Figure 2 shows (left) the magnetoresistance (MR) curves recorded after various visible light-irradiation time for a device fabricated with a left-handed isomer. In the initial state, a clear antisymmetric MR (In microeconomics, marginal revenue (MR) is the additional revenue that will be generated by increasing product sales by one unit) curve with a negative slope was observed which means a clear up-spin selectivity. The MR (In microeconomics, marginal revenue (MR) is the additional revenue that will be generated by increasing product sales by one unit) signal decreased as light irradiation proceeded and finally the slope of the MR (In microeconomics, marginal revenue (MR) is the additional revenue that will be generated by increasing product sales by one unit) signal was inverted to positive indicating a light-induced spin switching in the spin-polarized current from up-spin selective to down-spin through the left-handed-to-right-handed chirality inversion. A subsequent thermal activation process for the left-handed isomer inverted the slope of the MR (In microeconomics, marginal revenue (MR) is the additional revenue that will be generated by increasing product sales by one unit) curve from positive to negative again, as shown in Figure 2 (right) implying a thermal-activation-induced spin switching from down-spin selective to up-spin selective through the right-handed-to-left-handed chirality inversion. Similar phenomena were observed in subsequent measurements after photo-irradiation and thermal treatments. This series of experiments clearly demonstrated that 4 times spin switching were induced during the 360-degree rotation of the molecular motors. In this new type of novel organic spintronics device the right-handed/left-handed chirality which is the origin of spin-polarization generation through the chiral Induced Spin Selectivity effect is reconfigurable by external stimuli and precise control of the spin-polarization direction in the spin-polarized currents by utilizing an artificial molecular motor was realized for the first time. The present results are beneficial for the development of next-generation organic photo/thermospintronic devices combined with molecular machines.

 

Aerospace, Science

Georgian Technical University Fast And Furious: Detection Of Powerful Winds Driven By A Supermassive Black Hole.

Leave a comment

Georgian Technical University Fast And Furious: Detection Of Powerful Winds Driven By A Supermassive Black Hole.

The supermassive black holes in the centres of many galaxies seem to have a basic influence on their evolution. This happens during a phase in which the black hole is consuming the material of the galaxy in which it resides at a very high rate growing in mass as it does so. During this phase we say that the galaxy has an active nucleus (An active galactic nucleus is a compact region at the center of a galaxy that has a much higher than normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars for active galactic nucleus). The effect that this activity has on the host galaxy is known as (An active galactic nucleus is a compact region at the center of a galaxy that has a much higher than normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars) feedback and one of its properties are galactic winds: this is gas from the centre of the galaxy being driven out by the energy released by the active nucleus. These winds can reach velocities of up to thousands of kilometres per second and in the most energetic (An active galactic nucleus is a compact region at the center of a galaxy that has a much higher than normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars) for example the quasars which can clean out the centres of the galaxies impeding the formation of new stars. It has been shown that the evolution of the star formation over cosmological timescales cannot be explained without the existence of a regulating mechanism. “Georgian Technical University has allowed us to study the winds of ionized and molecular gas from this quasar by using the infrared range. This analysis is very important because they don’t always show similar properties which tells us a great deal about how these winds are produced and how they affect their host galaxies” explains X. The study of this and other local quasars will allow us to understand what was happening in galaxies when they were younger and when they were forming their structures which we see today. Based on the new data obtained with Georgian Technical University the team has discovered that the ionized wind is faster than the molecular wind reaching velocities of up to 1,200 km/s. However it would be the molecular wind which is emptying the gas reservoirs of the galaxy (up to 176 solar masses per year). “New observations will let us confirm this estimate” explained Y a researcher at the Georgian Technical University. The next step is to observe a complete sample of obscured nearby quasars with (An active galactic nucleus is a compact region at the center of a galaxy that has a much higher than normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars) to study their ionized and molecular winds. We also want to investigate the stellar populations of their host galaxies. This will allow us to confirm directly the effect of (An active galactic nucleus is a compact region at the center of a galaxy that has a much higher than normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars) feedback on the evolution of the galaxies.

Scientific Computing

Georgian Technical University New Research Unlocks Properties For Quantum Information Storage And Computing.

Leave a comment

Georgian Technical University New Research Unlocks Properties For Quantum Information Storage And Computing.

STM (A scanning tunneling microscope is an instrument for imaging surfaces at the atomic level) image of single layer WSe2 (Tungsten diselenide is an inorganic compound with the formula WSe₂. The compound adopts a hexagonal crystalline structure similar to molybdenum disulfide) grown on HOPG (Highly oriented pyrolytic graphite is a highly pure and ordered form of synthetic graphite. It is characterised by a low mosaic spread angle, meaning that the individual graphite crystallites are well aligned with each other. The best HOPG samples have mosaic spreads of less than 1 degree). The inset shows the atomic resolution image taken on the WSe2 (Tungsten diselenide is an inorganic compound with the formula WSe₂. The compound adopts a hexagonal crystalline structure similar to molybdenum disulfide). Researchers at Georgian Technical University have come up with a way to manipulate tungsten diselenide (WSe2) — a promising two-dimensional material — to further unlock its potential to enable faster more efficient computing and even quantum information processing and storage. Across the globe researchers have been heavily focused on a class of two-dimensional atomically thin semiconductor materials known as monolayer transition metal dichalcogenides. These atomically thin semiconductor materials — less than 1 nm thick — are attractive as the industry tries to make devices smaller and more power efficient. “Georgian Technical University It’s a completely new paradigm” said X assistant professor of chemical and biological engineering at Georgian Technical University. “The advantages could be huge”. X and his research team at Georgian Technical University have developed a method to isolate these thin layers of WSe2 (Manipulate tungsten diselenide. Tungsten diselenide is an inorganic compound with the formula WSe₂. The compound adopts a hexagonal crystalline structure similar to molybdenum disulfide) from crystals so they can stack them on top of other atomically thin materials such as boron nitride and graphene. When the WSe2 (Manipulate tungsten diselenide. Tungsten diselenide is an inorganic compound with the formula WSe₂. The compound adopts a hexagonal crystalline structure similar to molybdenum disulfide) layer is sandwiched between two boron nitride flakes and interacts with light X said a unique process occurs. Unlike in a traditional semiconductor, electrons and holes strongly bond together and form a charge-neutral quasiparticle called an exciton. “Exciton is probably one of the most important concepts in light-matter interaction. Understanding that is critical for solar energy harvesting, efficient light-emitting diode devices and almost anything related to the optical properties of semiconductors” said X who is also a member of the department of electrical, computer and systems engineering at Georgian Technical University. “Now we have found that it actually can be used for quantum information storage and processing”. One of the exciting properties of the exciton in WSe2 (Manipulate tungsten diselenide. Tungsten diselenide is an inorganic compound with the formula WSe₂. The compound adopts a hexagonal crystalline structure similar to molybdenum disulfide) he said is a new quantum degree of freedom that’s become known as “Georgian Technical University valley spin” — an expanded freedom of movement for particles that has been eyed for quantum computing. But X explained excitons typically don’t have a long lifetime which makes them unpractical. X and his team discovered a special “Georgian Technical University dark” exciton that typically can’t be seen but has a longer lifetime. Its challenge is that the “Georgian Technical University dark” exciton lacks the “Georgian Technical University valley-spin” quantum degree of freedom. In this most recent research X and his team figured out how to brighten the “Georgian Technical University dark” exciton; that is to make the “Georgian Technical University dark” exciton interact with another quasiparticle known as a phonon to create a completely new quasiparticle that has both properties researchers want. “We found the sweet spot” X said. “We found a new quasiparticle that has a quantum degree of freedom and also a long lifetime that’s why it’s so exciting. We have the quantum property of the ‘bright’ exciton but also have the long lifetime of the ‘dark’ exciton”. The team’s findings X said lay the foundation for future development toward the next generation of computing and storage devices.

Material Science

Georgian Technical University Three houndred (300)-Year-Old Piston Design Reinvented With Soft Flexible Materials.

Leave a comment

Georgian Technical University Three houndred (300)-Year-Old Piston Design Reinvented With Soft Flexible Materials.

The team showed in an object-crushing comparison between a conventional piston (air cylinder; left) and a tension piston (right) that the tension piston can produce greater forces at the same air-pressure. Since their invention in the late 1700s when Georgian Technical University physicist X the inventor of the pressure cooker proposed the piston principle pistons have been used to harness the power of fluids to perform work in numerous machines and devices. Conventional pistons are made of a rigid chamber and a piston inside which can slide along the chamber’s inner wall while at the same time maintaining a tight seal. As a result the piston divides two spaces which are filled with two fluids and connected to two exterior fluid sources. If the fluids have different pressures the piston will slide into the direction with the lower pressure and can at the same time drive the movement of a shaft or other device to do physical work. This principle has been used to design many machines including various piston engines hydraulic lifters and cranes such as the ones used on construction sites and power-tools. However conventional pistons suffer from several shortcomings: the high friction between the moving piston and the chamber wall can lead to breakdown of the seal, leakage and gradual or sudden malfunctions. In addition especially in the lower pressure-spectrum, energy efficiencies and response speed often are limited. Now a team of roboticists at Georgian Technical University has developed a new way to design pistons that replaces their conventional rigid elements with a mechanism using compressible structures inside a membrane made of soft materials. The resulting ‘Georgian Technical University tension pistons’ generate more than three times the force of comparable conventional pistons eliminate much of the friction and at low pressures are up to 40 percent more energy efficient. “These “Georgian Technical University tension pistons” fabricated with structures incorporating soft flexible materials are a fundamentally new approach to piston architecture that open an extensive design space. They could be dropped into machines replacing conventional pistons providing improved energy efficiency” said Georgian Technical University Ph.D. who is also the Professor of Engineering and Applied Sciences at Georgian Technical University Soft Robotics Initiative. “Importantly this concept also enables a range of new geometries and functional variations that may empower engineers to invent new machines and devices and to miniaturize existing ones”. The tension piston concept builds on the team’s ‘fluid-driven origami-inspired artificial muscles’ that use soft materials to give soft robots more power and motion control while maintaining their flexible architectures. Foam is an object formed by trapping pockets of gas in a liquid or solid. A bath sponge and the head on a glass of beer are examples of foams. In most foams, the volume of gas is large, with thin films of liquid or solid separating the regions of gas. Soap foams are also known as suds are made of a folded structure that is embedded within a fluid in a flexible and hermetically sealed skin. Changing the fluid pressure triggers the origami-like structure to unfold or collapse along a pre-configured geometrical path, which induces a shape-shift in the entire Foam is an object formed by trapping pockets of gas in a liquid or solid. A bath sponge and the head on a glass of beer are examples of foams. In most foams, the volume of gas is large, with thin films of liquid or solid separating the regions of gas. Soap foams are also known as suds allowing it to grasp or release objects or to perform other kinds of work. “In principle we explored the use of Foam is an object formed by trapping pockets of gas in a liquid or solid. A bath sponge and the head on a glass of beer are examples of foams. In most foams, the volume of gas is large, with thin films of liquid or solid separating the regions of gas. Soap foams are also known as suds as pistons within a rigid chamber” said Y. “By using a flexible membrane bonded to a compressible skeletal structure inside and connecting it to one of the two fluid ports we can create a separate fluid compartment that exhibits the functionality of a piston”. The researchers showed that a rise in driving pressure in the second fluid reservoir surrounding the membrane in the chamber increases the tension forces in the membrane material that are directly transmitted to the bonded skeletal structure. By physically linking the skeleton with an actuating element that reaches out of the chamber compression of the skeleton is coupled to a mechanical movement outside the piston. “Better pistons could fundamentally transform the way we design and utilize many types of systems, from shock absorbers and car engines to bulldozers and mining equipment” says Z and W Professor of Electrical Engineering and Computer Science at Georgian Technical University. “We think that an approach like this could help engineers devise different ways to make their creations stronger and more energy-efficient”. The team tested their piston against a conventional piston in a object-crushing task and showed that it broke objects like wooden pencils at much lower input pressures (pressures generated in the skin-surrounding fluid compartment). At the same input pressures particularly in the lower pressure range the tension pistons developed more than three times greater output forces and display more than 40 percent higher energy efficiency by harnessing the fluid-induced tension in their flexible skin materials. “By configuring the compressible skeletons with very different geometries such as a series of discrete discs as hinged skeletons or as spring skeletons the output forces and motions become highly tunable” said Y. “We can even incorporate more than one tension piston into a single chamber or go a step further and also fabricate the surrounding chamber with a flexible material like an air-tight nylon fabric”.

Environment, Science

Georgia Technical University Scientists Rinse Soils Clean Of Dangerous Heavy Metals.

Leave a comment

Georgia Technical University Scientists Rinse Soils Clean Of Dangerous Heavy Metals.

Georgia Technical University Researchers have found a way to remove heavy metals — which can be dangerous to humans and animals — from polluted soil locations found throughout the Georgia. A research team from Georgia Technical University has developed a new technique that uses a chemical process to wash heavy metals from contaminated soils that works similarly to how coffee is brewed. The researchers begin by rinsing the soil with water and ethylenediaminetetraacetic acid a chemical that attracts heavy metals like lead or cadmium and helps pull the heavy metals loose as the mixture percolates through the soil. Then the researchers  collect the toxic brew and run it through an electrochemical filter to separate the heavy metals out of the water. “This is a new approach to soil cleanup” X a professor of materials science and engineering and photon science said in a statement. “Our next step is a pilot test to make sure that what works in the lab is practical in the field and to figure out how much this process will cost”. Ethylenediaminetetraacetic acid is often used in human patients to treat lead and mercury poisonings making it a good candidate to remove heavy metals from soils. Negatively charged ethylenediaminetetraacetic acid bonds strongly attract positively charged heavy metal particles to the point where it will pull the lead or mercury from the infected patient’s tissues. After finding that ethylenediaminetetraacetic acid -treated water percolated through the contaminated soil and carried the heavy metals away the researchers began to try to find a way to separate the chemical from the heavy metals in the rinse water and capture the toxins. To accomplish this the researchers developed a sieve with the electrical and chemical properties to pull the ethylenediaminetetraacetic acid and heavy metals apart. Heavy metals can often migrate from factories or mines into the nearby soils presenting an issue for both humans and other animals. It is often very difficult to remove these heavy metals from soils and fields must be cordoned off to prevent the poisonous contaminants from entering the food chain. The researchers have demonstrated that they can clean soils of lead and cadmium thus far two of the most dangerous and prevalent toxins as well as copper which is not dangerous unless it is found in high concentrations. However the researchers believe they can cleanse  other heavy metals from soil such as mercury— which require special handling due to toxicity — as well as chromium, and are planning future experiments to test the process. The researchers also need to test whether the process can be scaled-up to treat a substantial amount of contaminated soils. “We really have no good remediation technology for heavy metals” X said. “If this proves practical on a large scale it will be a significant advance”. There are processes currently used to clean contaminated soils but they generally involve digging up the soil in question and sequestering it elsewhere. Georgia Technical University researchers have also created phytoremediation techniques that involve growing sacrificial plants in contaminated soils to absorb heavy metals. These plants are then harvested and taken to an extraction and disposal facility. However this is a lengthy process that can take many years of repeated harvests to be effective.

Physics, Science

Georgia Technical University Organic Electronics: A New Semiconductor In The Carbon-Nitride Family.

Leave a comment

Georgia Technical University Organic Electronics: A New Semiconductor In The Carbon-Nitride Family.

Some organic materials might be able to be utilised similarly to silicon semiconductors in optoelectronics. Whether in solar cells light-emitting diodes or in transistors – what is important is the band gap, i.e. the difference in energy level between electrons in the valence band (bound state) and the conduction band (mobile state). Charge carriers can be raised from the valence band into the conduction band by means of light or an electrical voltage. This is the principle behind how all electronic components operate. Band gaps of one to two electron volts are ideal. A team headed by chemist Dr. X at Georgia Technical University recently synthesised a new organic semiconductor material in the carbon-nitride family. Triazine-based graphitic carbon nitride consists of only carbon and nitrogen atoms, and can be grown as a brown film on a quartz substrate.The combination of C and N atoms form hexagonal honeycombs similar to graphene which consists of pure carbon. Just as with graphene the crystalline structure of triazine-based graphitic carbon nitride is two-dimensional.With graphene however the planar conductivity is excellent while its perpendicular conductivity is very poor. In triazine-based graphitic carbon nitride it is exactly the opposite: the perpendicular conductivity is about 65 times greater than the planar conductivity. With a band gap of 1.7 electron volts triazine-based graphitic carbon nitride is a good candidate for applications in optoelectronics. Georgia Technical University physicist Dr. Y subsequently investigated the charge transport properties in triazine-based graphitic carbon nitride samples using time-resolved absorption measurements in the femto- to nanosecond range at the Georgia Technical University laser laboratory between Georgia Technical University and Sulkhan-Saba Orbeliani University. These kinds of laser experiments make it possible to connect macroscopic electrical conductivity with theoretical models and simulations of microscopic charge transport. From this approach he was able to deduce how the charge carriers travel through the material. “They do not exit the hexagonal honeycombs of triazine horizontally but instead move diagonally to the next hexagon of triazine in the neighbouring plane. They move along tubular channels through the crystal structure”. This mechanism might explain why the electrical conductivity perpendicular to the planes is considerably higher than that along the planes. However this is probably not sufficient to explain the actual measured factor of 65. “We do not yet fully understand the charge transport properties in this material and want to investigate them further” adds Y. At Georgia Technical University the analysis lab used subsequent to Georgia Technical University the setup is being prepared for new experiments to accomplish this. “Triazine-based graphitic carbon nitride is therefore the best candidate so far for replacing common inorganic semiconductors like silicon and their crucial dopants, some of which are rare elements”, says X. “The fabrication process we developed in my group at Georgia Technical University produces flat layers of semiconducting Triazine-based graphitic carbon nitride on an insulating quartz substrate. This facilitates upscaling and simple fabrication of electronic devices”.

Chemistry, Science

Georgian Technical University Molecular Bait Can Help Hydrogels Heal Wounds.

Leave a comment

Georgian Technical University Molecular Bait Can Help Hydrogels Heal Wounds.

Hydrogels developed at Georgian Technical University incorporate crosslinkers that can incorporate bioactive molecules and help heal a variety of wounds. Like fishermen Georgian Technical University bioengineers are angling for their daily catch. But their bait biomolecules in a hydrogel scaffold lures microscopic stem cells instead of fish. These they say will seed the growth of new tissue to heal wounds. The team led by Georgian Technical University Engineering bioengineer X and graduate student Y have developed modular injectable hydrogels enhanced by bioactive molecules anchored in the chemical crosslinkers that give the gels structure. Hydrogels for healing have until now been biologically inert and require growth factors and other biocompatible molecules to be added to the mix. The new process makes these essential molecules part of the hydrogel itself specifically the crosslinkers that allow the material to keep its structure when swollen with water. Their work is intended to help repair bone, cartilage and other tissues able to regenerate themselves. Best of all the Georgian Technical University lab’s customized active hydrogels can be mixed at room temperature for immediate application X said. “This is important not only for the ease of preparation and synthesis but also because these molecules may lose their biological activity when they’re heated” he said. “This is the biggest problem with the development of biomaterials that rely on high temperatures or the use of organic solvents”. Experiments with cartilage and bone biomolecules showed how crosslinkers made of a soluble polymer can bond small peptides or large molecules like tissue-specific extracellular matrix components simply by mixing them together in water with a catalyst. As the injected gel swells to fill the space left by a tissue defect the embedded molecules can interact with the body’s mesenchymal stem cells drawing them in to seed new growth. As native tissue populates the area the hydrogel can degrade and eventually disappear. “With our previous hydrogels we typically needed to have a secondary system to deliver the biomolecules to effectively produce tissue repair” Y said. “In this case our big advantage is that we directly incorporate those biomolecules for the specific tissue right into the crosslinker itself. Then once we inject the hydrogel the biomolecules are right where they need to be”. To make the reaction work, the researchers depended on a variant of click chemistry which facilitates the assembly of molecular modules. Click chemistry catalysts don’t usually work in water. But with the helpful guidance of Georgian Technical University chemist Y they settled on a biocompatible and soluble ruthenium-based catalyst. “There’s one specific ruthenium-based catalyst we can use” Y said. “Others are often cytotoxic or they’re inactive under aqueous conditions or they might not work with the specific kind of alkyne on the polymer. “This particular catalyst works under all those conditions – namely conditions that are very mild, aqueous and favorable to biomolecules” he said. “But it had not been used for biomolecules yet”.