MIT: Key flow mechanisms, crucial to carbon sequestration, Oil recovery and fuel-cell operation, have been visualized.


MIT-Multiphase-Flow_0 Wetability 082616

Lab experiments carried out by an MIT and Oxford University team provide detailed information about how a liquid moves through spaces in a porous material, revealing the key role of a characteristic called wettability.

Courtesy of the researchers

One of the most promising approaches to curbing the flow of human-made greenhouse gases into the atmosphere is to capture these gases at major sources, such as fossil-fuel-burning power plants, and then inject them into deep, water-saturated rocks where they can remain stably trapped for centuries or millennia.

This is just one example of fluid-fluid displacement in a porous material, which also applies to a wide variety of natural and industrial processes — for example, when rainwater penetrates into soil by displacing air, or when oil recovery is enhanced by displacing the oil with injected water.

Now, a new set of detailed lab experiments has provided fresh insight into the physics of this phenomenon, under an unprecedented range of conditions. These results should help researchers understand what happens when carbon dioxide flows through deep saltwater reservoirs, and could shed light on similar interactions such as those inside fuel cells being used to produce electricity without burning hydrocarbons.

The new findings are being published this week in the journal PNAS, in a paper by Ruben Juanes, MIT’s ARCO Associate Professor in Energy Studies; Benzhong Zhao, an MIT graduate student; and Chris MacMinn, an associate professor at Oxford University.

A crucial aspect of fluid-fluid displacement is the displacement efficiency, which measures how much of the pre-existing fluid can be pushed out of the pore space. High displacement efficiency means that most of the pre-existing fluid is pushed out, which is usually a good thing — with oil recovery, for example, it means that more oil would be captured and less would be left behind. Unfortunately, displacement efficiency has been very difficult to predict.

A key factor in determining displacement efficiency, Juanes says, is a characteristic called wettability. Wettability is a material property that measures a preference by the solid to be in contact with one of the fluids more than the other. The team found that the stronger the preference for the injected fluid, the more effective the displacement of the pre-existing fluid from the pores of the material — up to a point. But if the preference for the injected fluid increases beyond that optimal point, the trend reverses, and the displacement becomes much less efficient. The discovery of the existence of this ideal degree of wettability is one of the significant findings of the new research.

The work was partly motivated by recent advances in scanning techniques that make it possible to “directly characterize the wettability of real reservoir rocks under in-situ conditions,” says Zhao. But just being able to characterize the wettability was not sufficient, he explains. The key question was “Do we understand the physics of fluid-fluid displacement in a porous medium under different wettability conditions?” And now, after their detailed analysis, “We do have a fundamental understanding” of the process, Zhao says. MacMinn adds that “it comes from the design of a novel system that really allowed us to look in detail at what is happening at the pore scale, and in three dimensions.”

This GIF shows the way fluid distribution through pore spaces varies under different injection rates of water. The colors show the degree of saturation of the invading water. At low rates (left), the water advances in rapid bursts followed by quiet periods. At intermediate rates (center), the invading fluid advances by sequentially coating the walls of posts used to simulate pores in the team’s microfluidic cell. At high rates (right), the water advances in thin films along the solid surfaces.

 

 

 

 

 

 

 

In order to clearly define the physics behind these flows, the researchers did a series of lab experiments in which they used different porous materials with a wide range of wetting characteristics, and studied how the flows varied.

In natural environments such as aquifers or oil reservoirs, the wettability of the material is predetermined. But even so, Juanes says, “there are ways you can modify the wettability in the field,” such as by adding specific chemical compounds like surfactants (similar to soap) to the injected fluid.

By making it possible to understand just what degree of wettability is desirable for a particular situation, the new findings “in principle, could be very advantageous” for designing carbon sequestration or enhanced oil recovery schemes for a specific geological setting.

The same principles apply to some polymer electrolyte fuel cells, where water vapor condenses at the fuel cell’s cathode and has to migrate through a porous membrane. Depending on the exact mix of gas and liquid, these flows can be detrimental to the performance of the fuel cell, so controlling and predicting the way these flows work can be important in designing such cells.

In addition, the same process of liquid and gas interacting in pore spaces also applies to the way freshwater aquifers get recharged by rainfall, as the water percolates into the ground and displaces air in the soil. A better understanding of this process could be important for management of ever-scarcer water resources, the team says.

“This is a very interesting study of pore-scale multiphase fluid flow in two-dimensional micromodels,” says David Weitz, a professor of physics and applied physics at Harvard University, who was not involved in this work. “The advantage of this work is that the authors look in more detail at the mechanisms of wetting and displacement of the fluid in the pores,” he says. “This is a very important aspect of fluid flow in porous media.”

This research was supported by the U.S. Department of Energy and the MIT Energy Initiative.

How can we store solar energy for periods when the sun doesn’t shine? Researchers Turn to Known – Effective – Low Cost Method with a “Twist”


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How can we store solar energy for period when the sun doesn’t shine?

 

One solution is to convert it into hydrogen through water electrolysis. The idea is to use the electrical current produced by a solar panel to ‘split’ water molecules into hydrogen and oxygen. Clean hydrogen can then be stored away for future use to produce electricity on demand, or even as a fuel.

 
But this is where things get complicated. Even though different hydrogen-production technologies have given us promising results in the lab, they are still too unstable or expensive and need to be further developed to use on a commercial and large scale.
The approach taken by EPFL and CSEM researchers is to combine components that have already proven effective in industry in order to develop a robust and effective system. Their prototype is made up of three interconnected, new-generation, crystalline silicon solar cells attached to an electrolysis system that does not rely on rare metals.

The device is able to convert solar energy into hydrogen at a rate of 14.2%, and has already been run for more than 100 hours straight under test conditions. In terms of performance, this is a world record for silicon solar cells and for hydrogen production without using rare metals. It also offers a high level of stability.

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The device is able to convert solar energy into hydrogen at a rate of 14.2 percent, and has already been run for more than 100 hours straight. (Image: Infini Lab / EPFL)
Enough to power a fuel cell car over 10,000km every year

An Effective and Low-Cost Solution for Storing Solar Energy

 

The method, which surpasses previous efforts in terms of stability, performance, lifespan and cost efficiency, is published in the Journal of The Electrochemical Society (“Solar-to-Hydrogen Production at 14.2% Efficiency with Silicon Photovoltaics and Earth-Abundant Electrocatalysts”). “A 12-14 m2 system installed in Switzerland would allow the generation and storage of enough hydrogen to power a fuel cell car over 10,000 km every year”, says Christophe Ballif, who co-authored the paper.

 
High voltage cells have an edge

 
The key here is making the most of existing components, and using a ‘hybrid’ type of crystalline-silicon solar cell based on hetero-junction technology. The researchers’ sandwich structure – using layers of crystalline silicon and amorphous silicon – allows for higher voltages. And this means that just three of these cells, interconnected, can already generate an almost ideal voltage for electrolysis to occur. The electro-chemical part of the process requires a catalyst made from nickel, which is widely available.

 
“With conventional crystalline silicon cells, we would have to link up four cells to get the same voltage,” says co-author Miguel Modestino at EPFL.”So that’s the strength of this method.”

 
A stable and economically viable method 

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The new system is unique when it comes to cost, performance and lifespan. “We wanted to develop a high performance system that can work under current conditions,” says Jan-Willem Schüttauf, a researcher at CSEM and co-author of the paper. “The hetero-junction cells that we use belong to the family of crystalline silicon cells, which alone account for about 90% of the solar panel market. It is a well-known and robust technology whose lifespan exceeds 25 years.

And it also happens to cover the south side of the CSEM building in Neuchâtel.”
The researchers used standard hetero-junction cells to prove the concept; by using the best cells of that type, they would expect to achieve a performance above 16%.

 
Source: Ecole Polytechnique Fédérale de Lausanne

 

Nanoporous Material Combines the Best of Batteries and Supercapacitors for ESS (Energy Storage Systems)


An Emerging Technology that has the potential to bring “Paying with Your Phone” together with the Convenience of Paying with a “Digital Powered Smart Card!”

Phone Pay 082316 safe_image (1)Also Follow This Link: Why Isn’t Anyone Paying with their Phone Yet?

Great Things from Small Things .. Nanotechnology Innovation

Rice Nanoporus Battery 102315 untitledPhoto: Jeff Fitlow

Researchers at Rice University in Houston, Texas, have developed a nanoporous material that has the energy density (the amount of energy stored per unit mass) of an electrochemical battery and the power density (the maximum amount of power that can be supplied per unit mass) of a supercapacitor. It’s important to note that the energy storage device enabled by the material is not claimed to be either of these types of energy storage devices.

The research community has wearied of claims that some new nanomaterial enables a “supercapacitor,” when in fact the energy storage device is not a supercapacitor at all, but a battery. However, in this case, the Rice University researchers, led by James Tour, who is known for having increased the storage capacity of lithium-ion (Li-ion) batteries with graphene, don’t make any claims that the device they created is a supercapacitor. Instead it is described…

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U of California: Nano submarines could change healthcare, says nanoengineer professor


Nano Subs 082316 1471860105809A leading global chemist has come to the Sunshine Coast to discuss how his team is close to creating a successful nano submarine that could revolutionise the healthcare system.

When asked what exactly a “nano submarine” was, University of California San Diego chair of nanoengineering professor Joseph Wang described it as like something taken from the 1966 film Fantastic Voyage, where medical personnel board a submarine were shrunk to microscopic size to travel through the bloodstream of a wounded diplomat and save his life.

Professor Wang said his team was getting closer to the goal of using nano submarines in a variety of ways, minus the shrunken humans and sabotage of the 1966 film.

“It’s like the Fantastic Voyage movie, where you want to improve therapeutic and diagnostic abilities through proper timing and proper location to improve efficiency,” he said.

“It is like shrinking a big submarine a million times to get the nano-scale submarine.

“We use special nano fabrications to create it.

“You can call it submarine or a nano machine, there are different names for it.”

One nanometer is one-billionth of a meter. To put this into perspective, a strand of human DNA is 2.5 nanometers in diameter while a sheet of paper is about 100,000 nanometers thick.Nano Subs 061416 untitled

Professor Wang said the nano submarines could be tailored to specific applications, including diagnosis, treatment and imaging and would use energy within the body’s system to generate its movement.

“It is powered by the blood, by chemical in the blood like glucose, it can autonomously move in blood,” he said.

“This is all part of what we call nano medicine, precision medicine that we use to improve medicines.

“It could improve imaging, diagnosis, treatment, it is multifunctional.”

Professor Wang said there was a fair way to go before human testing could begin, but said the pioneering work could improve drug treatments by providing a more targeted approach.

“Compared to (current) drug delivery, it could take cargo, the drug, and dispose it at the right location, right time and could improve the efficiency of drug,” he said.

Professor Wang was presenting a free public seminar on nano submarines at University of Sunshine Coast’s Innovation Centre at Sippy Downs.

 

Nanoparticles that Speed Blood Clotting ~ Great Things from Small Things ~ May One Day Save Lives


Blood Clot NPs 082216 10-nanoparticle.jpgNanoparticles (green) help form clots in an injured liver. The researchers added color to the scanning electron microscopy image after it was taken. Credit: Erin Lavik, Ph.D.

Whether severe trauma occurs on the battlefield or the highway, saving lives often comes down to stopping the bleeding as quickly as possible. Many methods for controlling external bleeding exist, but at this point, only surgery can halt blood loss inside the body from injury to internal organs.

Now, researchers have developed nanoparticles that congregate wherever injury occurs in the body to help it form blood clots, and they’ve validated these particles in test tubes and in vivo.

The researchers will present their work today at the 252nd National Meeting & Exposition of the American Chemical Society (ACS).

“When you have uncontrolled internal bleeding, that’s when these particles could really make a difference,” says Erin B. Lavik, Sc.D. “Compared to injuries that aren’t treated with the nanoparticles, we can cut bleeding time in half and reduce total .”

Trauma remains a top killer of children and younger adults, and doctors have few options for treating internal bleeding. To address this great need, Lavik’s team developed a nanoparticle that acts as a bridge, binding to activated platelets and helping them join together to form clots. To do this, the nanoparticle is decorated with a molecule that sticks to a glycoprotein found only on the activated platelets.

Nano Body II 43a262816377a448922f9811e069be13Initial studies suggested that the nanoparticles, delivered intravenously, helped keep rodents from bleeding out due to brain and spinal , Lavik says. But, she acknowledges, there was still one key question: “If you are a rodent, we can save your life, but will it be safe for humans?”

As a step toward assessing whether their approach would be safe in humans, they tested the immune response toward the particles in pig’s blood. If a treatment triggers an immune response, it would indicate that the body is mounting a defense against the nanoparticle and that side effects are likely. The team added their nanoparticles to pig’s blood and watched for an uptick in complement, a key indicator of immune activation. The particles triggered complement in this experiment, so the researchers set out to engineer around the problem.

“We made a battery of particles with different charges and tested to see which ones didn’t have this immune-response effect,” Lavik explains. “The best ones had a neutral charge.” But neutral nanoparticles had their own problems. Without repulsive charge-charge interactions, the nanoparticles have a propensity to aggregate even before being injected. To fix this issue, the researchers tweaked their nanoparticle storage solution, adding a slippery polymer to keep the nanoparticles from sticking to each other.

Lavik also developed nanoparticles that are stable at higher temperatures, up to 50 degrees Celsius (122 degrees Fahrenheit). This would allow the particles to be stored in a hot ambulance or on a sweltering .

In future studies, the will test whether the new particles activate complement in human blood. Lavik also plans to identify additional critical safety studies they can perform to move the research forward. For example, the team needs to be sure that the do not cause non-specific clotting, which could lead to a stroke. Lavik is hopeful though that they could develop a useful clinical product in the next five to 10 years.

Explore further: Researchers take the inside route to halt bleeding

More information: Engineering nanoparticles to stop internal bleeding, 252nd National Meeting & Exposition of the American Chemical Society (ACS), 2016.

Abstract
Young people between 5 and 44 are most likely to die from a trauma, and the primary cause of death will be bleeding out. We have a range of technologies to control external bleeding, but there is a dearth of technologies for internal bleeding.
Following injury, platelets become activated at the injury site.

We have designed nanoparticles that are administered intravenously that bind with activated platelets to help form platelet plugs more rapidly. We have investigated the behavior of these particles in an number of in vitro systems to understand their behavior. We have also tested these particles in a number of models of trauma. The particles lead to a reduction in bleeding in a number of models of trauma including models of brain and spinal cord injury, and these particles lead to increased survival.
This work is not without challenges. One of the goals is to be able to use these particles in places where there are extreme temperatures and storage is challenging. We have engineering a variant of the hemostatic nanoparticles that is stable up to 50 C. A second challenge is that the intravenous administration of nanoparticles triggers complement activation as has been seen in a wide range of nanoparticle technologies from DOXIL to imaging agents.

The solution is generally to administer the particles very slowly to modulate the physiological responses to complement activation, but that is not an option when one is bleeding out, so we have had to develop variants that reduce complement activation and the accompanying complications.
Ultimately, we hope that this work provides insight and, potentially, a new approach to dealing with internal bleeding.

 

‘Artificial atom’ Created in Graphene ~ What will this Mean? For Quantum Computers? For Quantum Dots?


Artificial Atom QDs 082216 artificialatThe charged tip of a scanning tunneling microscope and an additional magnetic field lead to localized stable electron states in graphene. Credit: Nils Freitag, RWTH Aachen

“Artificial atoms open up new, exciting possibilities, because we can directly tune their properties”, says Professor Joachim Burgdörfer (TU Wien, Vienna).In semiconductor materials such as gallium arsenide, trapping in tiny confinements has already been shown to be possible. These structures are often referred to as “quantum dots”. Just like in an atom, where the electrons can only circle the nucleus on certain orbits, electrons in these are forced into discrete quantum states.” QBits 2 050616 Researchers-Break-Room-Temperature-Quantum-Bit-Storage-Record

In a tiny quantum prison, electrons behave quite differently as compared to their counterparts in free space. They can only occupy discrete energy levels, much like the electrons in an atom – for this reason, such electron prisons are often called “artificial atoms”.

Artificial atoms may also feature properties beyond those of conventional ones, with the potential for many applications for example in quantum computing. Such additional properties have now been shown for artificial atoms in the carbon material graphene.

The results have been published in the journal Nano Letters, the project was a collaboration of scientists from TU Wien (Vienna, Austria), RWTH Aachen (Germany) and the University of Manchester (GB).

Building Artificial Atoms

“Artificial atoms open up new, exciting possibilities, because we can directly tune their properties”, says Professor Joachim Burgdörfer (TU Wien, Vienna).

 

In semiconductor materials such as gallium arsenide, trapping in tiny confinements has already been shown to be possible. These structures are often referred to as “quantum dots”. Just like in an atom, where the electrons can only circle the nucleus on certain orbits, electrons in these are forced into discrete quantum states.

Even more interesting possibilities are opened up by using graphene, a material consisting of a single layer of , which has attracted a lot of attention in the last few years. “In most materials, electrons may occupy two different quantum states at a given energy. The high symmetry of the graphene lattice allows for four different quantum states. This opens up new pathways for quantum information processing and storage” explains Florian Libisch from TU Wien. However, creating well-controlled artificial atoms in graphene turned out to be extremely challenging.

'Artificial atom' created in graphene
(Left) Florian Libisch, explaining the structure of graphene. Credit: TU Wien

 

 

 

Cutting edge is not enough

There are different ways of creating artificial atoms: The simplest one is putting electrons into tiny flakes, cut out of a thin layer of the material. While this works for graphene, the symmetry of the material is broken by the edges of the flake which can never be perfectly smooth. Consequently, the special four-fold multiplicity of states in graphene is reduced to the conventional two-fold one.

Therefore, different ways had to be found: It is not necessary to use small graphene flakes to capture electrons. Using clever combinations of electrical and magnetic fields is a much better option. With the tip of a scanning tunnelling microscope, an electric field can be applied locally. That way, a tiny region is created within the graphene surface, in which low energy electrons can be trapped. At the same time, the electrons are forced into tiny circular orbits by applying a magnetic field. “If we would only use an electric field, quantum effects allow the electrons to quickly leave the trap” explains Libisch.

The artificial atoms were measured at the RWTH Aachen by Nils Freitag and Peter Nemes-Incze in the group of Professor Markus Morgenstern. Simulations and theoretical models were developed at TU Wien (Vienna) by Larisa Chizhova, Florian Libisch and Joachim Burgdörfer. The exceptionally clean graphene sample came from the team around Andre Geim and Kostya Novoselov from Manchester (GB) – these two researchers were awarded the Nobel Prize in 2010 for creating graphene sheets for the first time.

The new artificial atoms now open up new possibilities for many quantum technological experiments: “Four localized electron states with the same energy allow for switching between different quantum states to store information”, says Joachim Burgdörfer.

The electrons can preserve arbitrary superpositions for a long time, ideal properties for quantum computers. In addition, the new method has the big advantage of scalability: it should be possible to fit many such on a small chip in order to use them for quantum information applications.

Explore further: Physicists create artificial ‘graphene’

More information: Nils M. Freitag et al, Electrostatically Confined Monolayer Graphene Quantum Dots with Orbital and Valley Splittings, Nano Letters (2016). DOI: 10.1021/acs.nanolett.6b02548

 

 

DOE to invest $16M in computational design of new materials for alt and renewable energy, electronics and other fields


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17 August 2016

The US Department of Energy will invest $16 million over the next four years to accelerate the design of new materials through use of supercomputers.

Two four-year projects—one team led by DOE’s Lawrence Berkeley National Laboratory (Berkeley Lab), the other teamled by DOE’s Oak Ridge National Laboratory (ORNL)—will leverage the labs’ expertise in materials and take advantage of lab supercomputers to develop software for designing fundamentally new functional materials destined to revolutionize applications in alternative and renewable energy, electronics, and a wide range of other fields. The research teams include experts from universities and other national labs.

The new grants—part of DOE’s Computational Materials Sciences (CMS) program launched in 2015 as part of the US Materials Genome Initiative—reflect the enormous recent growth in computing power and the increasing capability of high-performance computers to model and simulate the behavior of matter at the atomic and molecular scales.lawrence-berkeley-national-laboratory

The teams are expected to develop sophisticated and user-friendly open-source software that captures the essential physics of relevant systems and can be used by the broader research community and by industry to accelerate the design of new functional materials.

Berkeley_Lab_Logo_Small 082016The Berkeley Lab team will be led by Steven G. Louie, an internationally recognized expert in materials science and condensed matter physics. A longtime user of NERSC supercomputers, Louie has a dual appointment as Senior Faculty Scientist in the Materials Sciences Division at Berkeley Lab and Professor of Physics at the University of California, Berkeley. Other team members are Jack Deslippe, Jeffrey B. Neaton, Eran Rabani, Feng Wang, Lin-Wang Wang and Chao Yang, Lawrence Berkeley National Laboratory; and partners Daniel Neuhauser, University of California at Los Angeles, and James R. Chelikowsky, University of Texas, Austin.

This investment in the study of excited-state phenomena in energy materials will, in addition to pushing the frontiers of science, have wide-ranging applications in areas such as electronics, photovoltaics, light-emitting diodes, information storage and energy storage. We expect this work to spur major advances in how we produce cleaner energy, how we store it for use, and to improve the efficiency of devices that use energy.

—Steven Louie

ORNL researchers will partner with scientists from national labs and universities to develop software to accurately predict the properties of quantum materials with novel magnetism, optical properties and exotic quantum phases that make them well-suited to energy applications, said Paul Kent of ORNL, director of the Center for Predictive Simulation of Functional Materials, which includes partners from Argonne, Lawrence Livermore, Oak Ridge and Sandia National Laboratories and North Carolina State University and the University of California–Berkeley.ORNL 082016 steamplant_8186871_ver1.0_640_480

Our simulations will rely on current petascale and future exascale capabilities at DOE supercomputing centers. To validate the predictions about material behavior, we’ll conduct experiments and use the facilities of the Advanced Photon Source, Spallation Neutron Source and the Nanoscale Science Research Centers.

—Paul Kent

At Argonne, our expertise in combining state-of-the-art, oxide molecular beam epitaxy growth of new materials with characterization at the Advanced Photon Source and the Center for Nanoscale Materials will enable us to offer new and precise insight into the complex properties important to materials design. We are excited to bring our particular capabilities in materials, as well as expertise in software, to the center so that the labs can comprehensively tackle this challenge.

—Olle Heinonen, Argonne materials scientist

Researchers are expected to make use of the 30-petaflop/s Cori supercomputer now being installed at the National Energy Research Scientific Computing center (NERSC) at Berkeley Lab, the 27-petaflop/s Titan computer at the Oak Ridge Leadership Computing Facility (OLCF) and the 10-petaflop/s Mira computer at Argonne Leadership Computing Facility (ALCF). OLCF, ALCF, and NERSC are all DOE Office of Science User Facilities. One petaflop/s is 1015 or a million times a billion floating-point operations per second.

In addition, a new generation of machines is scheduled for deployment between 2016 and 2019 that will take peak performance as high as 200 petaflops. Ultimately the software produced by these projects is expected to evolve to run on exascale machines, capable of 1000 petaflops and projected for deployment in the mid-2020s.

Research will combine theory and software development with experimental validation, drawing on the resources of multiple DOE Office of Science User Facilities, including the Molecular Foundry and Advanced Light Source at Berkeley Lab, the Center for Nanoscale Materials and the Advanced Photon Source at Argonne National Laboratory (ANL), and the Center for Nanophase Materials Sciences and the Spallation Neutron Source at ORNL, as well as the other Nanoscience Research Centers across the DOE national laboratory complex.

The new research projects will begin in Fiscal Year 2016. Subsequent annual funding will be contingent on available appropriations and project performance.

The two new projects expand the ongoing CMS research effort, which began in FY 2015 with three initial projects, led respectively by ANL, Brookhaven National Laboratory and the University of Southern California.

MIT: World Water and Food Security Lab Receives $750K in Commercialization Awards


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Membrane structures in plant xylem from different species are being investigated for use in water filtration. Image: Karnik Lab

Four new projects and one renewal receive $150,000 in funding for 2016-2017.

The Abdul Latif Jameel World Water and Food Security Lab (J-WAFS) has announced four new grant recipients in its J-WAFS Solutions program. J-WAFS Solutions is sponsored by Abdul Latif Jameel Community Initiatives, and provides commercialization grants to help develop products and services that will have a significant impact on water and food security, with related economic and societal benefits.

The program, managed by the MIT Deshpande Center for Technological Innovation, is in its second year. Like direct Deshpande grants, the goal of the funding is to advance a technology to the point where it can attract customer interest and investments to commercialize a product and launch a spinout company, and/or to license the technology to an existing organization. Funds support work to refine and enhance an innovation, systematically explore potential markets, and assess commercial viability, whereby the technology and market risks are sufficiently reduced.

The four new grants go to faculty in the departments of Chemical Engineering, Chemistry, and Mechanical Engineering. John H. Lienhard V, director of J-WAFS and the Abdul Latif Jameel World Water and Food Security Professor, says that MIT faculty continue to devise innovative technologies that are applicable to a range of challenges in the food and water sectors:

“Commercializing effective technologies with sound business models is one of MIT’s most effective mechanisms to have a positive impact on the world,” he says. “The J-WAFS Solutions program is helping not only to stimulate creative problem solving, but also to support entrepreneurial faculty and students who are motivated by problems of global importance.”

Following on prior J-WAFS seed funding, Alan Hatton, the Ralph Landau Professor of Chemical Engineering Practice, has been awarded a commercialization grant for the development of an affordable and robust purification technology. Seeing a need for separation technologies that can be applied to water purification needs in a range of contexts — from point-of-source treatment to remote in-situ purification devices to large-scale, centralized wastewater treatment facilities — the lab has been developing electrochemically-mediated adsorptive processes for water treatment. J‑WAFS Solutions funding will support the development of a demonstration unit and exploration of commercial application opportunities.

A new project led by Rohit Karnik, associate professor in the Department of Mechanical Engineering, and co-PI Amy Smith, senior lecturer in the Department of Mechanical Engineering and co-director of D-Lab, takes avery different approach to water purification. Addressing the largely unmet need to provide safe and affordable drinking water to very low-income groups, Karnik is developing low-cost water filters that exploit the natural filtration capabilities of xylem tissue in wood. Particularly in regions lacking access to piped water supply systems, microbial contamination is a major threat to health. With J-WAFS Solutions funding, Karnik’s lab will work with Amy Smith to validate filtration performance in the lab and in the field, while also assessing the usability, desirability, and affordability of low-cost filters and devising a strategy for local manufacture and commercialization.

Gang Chen, the Carl Richard Soderberg Professor in Power Engineering and head of the Department of Mechanical Engineering, was funded for his proposal on “Floating, Heat Localizing Solar Receivers for Distributed Desalination.” The lab’s invention is a wavelength-selective, insulating, solar powered still (WISPS) tarp structure that can blanket ocean, lake, and pond surfaces to generate freshwater onsite. The project addresses the challenges associated with scalability, cost, and water safety associated with seawater desalination by capitalizing on a recent innovation by Chen that achieves high evaporation rates and high efficiency by localizing high temperatures to the water surface.

The fourth funded project addresses the need for simple and rapid detection of pathogenic bacteria in food and water samples in order to prevent widespread infection, illness, and even death. Using a carbohydrate array detection scheme based on specific binding interactions of bacteria with carbohydrates, Timothy Swager, the John D. MacArthur Professor of Chemistry, and Alexander M. Klibanov, Novartis Professor in Chemistry and Bioengineering, are developing a system that will be able to simultaneously detect multiple types of pathogenic bacterial strains. The project will focus initially on the occurrence of food poisoning from ground beef — a common problem because of the prevalence of E. coli contamination in beef and dairy cattle and because bacteria that may only be on the surface and readily killed by cooking become dispersed throughout the meat during the grinding process.

A one-year renewal grant was awarded for another project that is pursuing point-of use identification of contaminants in drinking water and food through a different technology. Jointly led by Professor Michael S. Strano of the Department of Chemical Engineering and Professor Anthony Sinskey of the Department of Biology, this interdisciplinary project is leveraging new MIT nanotechnology to develop a single integrated platform that can address all important food and water contaminants — including bacterial pathogens, heavy metals, and allergens — in a low cost, widely deployable nanosensor array.

Renee J. Robins, executive director of J-WAFS, noted that the new projects span various aspects of ensuring a safe supply of water and food:

“Whether the issue is clean water for a rural village in India or enjoying a juicy hamburger cooked on the grill without fear of food poisoning, MIT researchers are developing technologies that will greatly improve people’s ability to have clean water and safe food at their ready disposal,” she says.

Rice University: Nanoribbons in solutions mimic nature: Suitable for wide use in Biomimetics


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The tip of an atomic force microscope on a cantilevered arm is used to pull a graphene nanoribbon the same way it would be used to pull apart a protein or a strand of DNA in a Rice University lab. The microscope can be used to measure properties like rigidity in a material as it’s manipulated by the tip. Credit: Kiang Research Group/Rice University

Graphene nanoribbons (GNRs) bend and twist easily in solution, making them adaptable for biological uses like DNA analysis, drug delivery and biomimetic applications, according to scientists at Rice University.

Knowing the details of how GNRs behave in a solution will help make them suitable for wide use in biomimetics, according to Rice physicist Ching-Hwa Kiang, whose lab employed its unique capabilities to probe nanoscale like cells and proteins in wet environments. Biomimetic materials are those that imitate the forms and properties of natural materials.

The research led by recent Rice graduate Sithara Wijeratne, now a postdoctoral researcher at Harvard University, appears in the Nature journal Scientific Reports.

Graphene nanoribbons can be thousands of times longer than they are wide. They can be produced in bulk by chemically “unzipping” carbon nanotubes, a process invented by Rice chemist and co-author James Tour and his lab.

Their size means they can operate on the scale of biological components like proteins and DNA, Kiang said. “We study the mechanical properties of all different kinds of materials, from proteins to cells, but a little different from the way other people do,” she said. “We like to see how materials behave in solution, because that’s where biological things are.” Kiang is a pioneer in developing methods to probe the energy states of proteins as they fold and unfold.

She said Tour suggested her lab have a look at the of GNRs. “It’s a little extra work to study these things in solution rather than dry, but that’s our specialty,” she said.

Nanoribbons are known for adding strength but not weight to solid-state composites, like bicycle frames and tennis rackets, and forming an electrically active matrix. A recent Rice project infused them into an efficient de-icer coating for aircraft.

But in a squishier environment, their ability to conform to surfaces, carry current and strengthen composites could also be valuable.

“It turns out that graphene behaves reasonably well, somewhat similar to other biological materials. But the interesting part is that it behaves differently in a solution than it does in air,” she said. The researchers found that like DNA and proteins, nanoribbons in solution naturally form folds and loops, but can also form helicoids, wrinkles and spirals.

Kiang, Wijeratne and Jingqiang Li, a co-author and student in the Kiang lab, used to test their properties. Atomic force microscopy can not only gather high-resolution images but also take sensitive force measurements of nanomaterials by pulling on them. The researchers probed GNRs and their precursors, graphene oxide nanoribbons.

The researchers discovered that all nanoribbons become rigid under stress, but their rigidity increases as oxide molecules are removed to turn graphene oxide nanoribbons into GNRs. They suggested this ability to tune their rigidity should help with the design and fabrication of GNR-biomimetic interfaces.

“Graphene and graphene oxide materials can be functionalized (or modified) to integrate with various biological systems, such as DNA, protein and even cells,” Kiang said. “These have been realized in biological devices, biomolecule detection and molecular medicine. The sensitivity of graphene bio-devices can be improved by using narrow graphene materials like nanoribbons.”

Wijeratne noted are already being tested for use in DNA sequencing, in which strands of DNA are pulled through a nanopore in an electrified material. The base components of DNA affect the electric field, which can be read to identify the bases.

The researchers saw nanoribbons’ biocompatibility as potentially useful for sensors that could travel through the body and report on what they find, not unlike the Tour lab’s nanoreporters that retrieve information from oil wells.

Further studies will focus on the effect of the nanoribbons’ width, which range from 10 to 100 nanometers, on their properties.

Explore further: Graphene nanoribbons get metallic

More information: Sithara S. Wijeratne et al, Detecting the Biopolymer Behavior of Graphene Nanoribbons in Aqueous Solution, Scientific Reports (2016). DOI: 10.1038/srep31174

 

 

Nanorobots target cancerous tumours with precision


Nanorobots 081916 legionsofnanThe legions of nanorobotic agents are actually composed of more than 100 million flagellated bacteria — and therefore self-propelled — and loaded with drugs that moved by taking the most direct path between the drug’s injection point and …more

Researchers from Polytechnique Montréal, Université de Montréal and McGill University have just achieved a spectacular breakthrough in cancer research. They have developed new nanorobotic agents capable of navigating through the bloodstream to administer a drug with precision by specifically targeting the active cancerous cells of tumours. This way of injecting medication ensures the optimal targeting of a tumour and avoids jeopardizing the integrity of organs and surrounding healthy tissues. As a result, the drug dosage that is highly toxic for the human organism could be significantly reduced.

This scientific breakthrough has just been published in the prestigious journal Nature Nanotechnology in an article titled “Magneto-aerotactic bacteria deliver drug-containing nanoliposomes to tumour hypoxic regions.” The article notes the results of the research done on mice, which were successfully administered nanorobotic agents into colorectal tumours.

“These legions of nanorobotic agents were actually composed of more than 100 million flagellated bacteria – and therefore self-propelled – and loaded with drugs that moved by taking the most direct path between the drug’s injection point and the area of the body to cure,” explains Professor Sylvain Martel, holder of the Canada Research Chair in Medical Nanorobotics and Director of the Polytechnique Montréal Nanorobotics Laboratory, who heads the research team’s work. “The drug’s propelling force was enough to travel efficiently and enter deep inside the tumours.”

When they enter a tumour, the nanorobotic agents can detect in a wholly autonomous fashion the oxygen-depleted tumour areas, known as hypoxic zones, and deliver the drug to them. This hypoxic zone is created by the substantial consumption of oxygen by rapidly proliferative tumour cells. Hypoxic zones are known to be resistant to most therapies, including radiotherapy.

But gaining access to tumours by taking paths as minute as a and crossing complex physiological micro-environments does not come without challenges. So Professor Martel and his team used nanotechnology to do it.

Bacteria with compass

To move around, bacteria used by Professor Martel’s team rely on two natural systems. A kind of compass created by the synthesis of a chain of magnetic nanoparticles allows them to move in the direction of a magnetic field, while a sensor measuring oxygen concentration enables them to reach and remain in the tumour’s active regions. By harnessing these two transportation systems and by exposing the bacteria to a computer-controlled magnetic field, researchers showed that these bacteria could perfectly replicate artificial nanorobots of the future designed for this kind of task.

“This innovative use of nanotransporters will have an impact not only on creating more advanced engineering concepts and original intervention methods, but it also throws the door wide open to the synthesis of new vehicles for therapeutic, imaging and diagnostic agents,” Professor Martel adds. “Chemotherapy, which is so toxic for the entire human body, could make use of these natural nanorobots to move drugs directly to the targeted area, eliminating the harmful side effects while also boosting its therapeutic effectiveness.”

Explore further: Fantastic voyage: From science fiction to reality

More information: Ouajdi Felfoul et al, Magneto-aerotactic bacteria deliver drug-containing nanoliposomes to tumour hypoxic regions, Nature Nanotechnology (2016). DOI: 10.1038/NNANO.2016.137