By: Chenfeng Ke, Dartmouth College

Nanomachines are tiny molecules – more than 10,000 lined up side by side would be narrower than the diameter of a human hair – that can move when they receive an external stimulus. They can already deliver medication within a body and serve as computer memories at the microscopic level. But as machines go, they haven’t been able to do much physical work – until now. The Conversation

My lab has used nano-sized building blocks to design a smart material that can perform work at a macroscopic scale, visible to the eye. A 3-D-printed lattice cube made out of polymer can lift 15 times its own weight – the equivalent of a human being lifting a car.

Nobel-winning roots are rotaxanes

The design of our new material is based on Nobel Prize-winning research that turned mechanically interlocked molecules into work-performing machines at nanoscale – things like molecular elevators and nanocars.

Rotaxanes are one of the most widely investigated of these molecules. These dumbbell-shaped molecules are capable of converting input energy – in the forms of light, heat or altered pH – into molecular movements. That’s how these kinds of molecular structures got the nickname “nanomachines.”

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HydrogenSometimes the biggest advancements are the smallest in size.

A multidisciplinary team from Sandia National Laboratories recently demonstrated that notion by using nanoparticles and a nanoconfinement system to improve the performance of hydrogen storage materials. The researchers believe that this development is a step in the right direction to improve efficiency of hydrogen fuel cell electric vehicles.

Currently, hydrogen fuel cell electric vehicles store hydrogen as a high-pressure gas. However, the researchers argue that a solid material would be able to act like a sponge, with the ability to absorb and release hydrogen more efficiently. Using a hydrogen storage material of this nature could increase the amount of hydrogen able to be stored in a vehicle. In order to be efficient and competitive in the transportation sector, a hydrogen fuel cell electric vehicle would have to be able to travel 300 miles before refueling.

“There are two critical problems with existing sponges for hydrogen storage,” says Vitalie Stavila, co-author of the study and past ECS member. “Most can’t soak up enough hydrogen for cars. Also, the sponges don’t release and absorb hydrogen fast enough, especially compared to the 5 minutes needed for fueling.”

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By: Mike Williams, Rice University

Graphene

Rice University researchers have modeled a nanoscale sandwich, the first in what they hope will become a molecular deli for materials scientists.

Their recipe puts two slices of atom-thick graphene around nanoclusters of magnesium oxide that give the super-strong, conductive material expanded optoelectronic properties.

Rice materials scientist Rouzbeh Shahsavari and his colleagues built computer simulations of the compound and found it would offer features suitable for sensitive molecular sensing, catalysis and bio-imaging. Their work could help researchers design a range of customizable hybrids of two- and three-dimensional structures with encapsulated molecules, Shahsavari said.

The research appears this month in the Royal Society of Chemistry journal Nanoscale.

The scientists were inspired by experiments elsewhere in which various molecules were encapsulated using van der Waals forces to draw components together. The Rice-led study was the first to take a theoretical approach to defining the electronic and optical properties of one of those “made” samples, two-dimensional magnesium oxide in bilayer graphene, Shahsavari said.

“We knew if there was an experiment already performed, we would have a great reference point that would make it easier to verify our computations, thus allowing more reliable expansion of our computational results to identify performance trends beyond the reach of experiments,” Shahsavari said.

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By using one of the world’s most powerful electron microscopes, a team of researchers from Lawrence Berkeley National Laboratory has successfully mapped the exact location and chemical type of 23,000 atoms in a nanoparticle made of iron and platinum. The team believes this work could reveal more information about material properties at the single-atom level, opening the doors to improving magnetic performance for next-generation hard drives.

“Our research is a big step in this direction. We can now take a snapshot that shows the positions of all the atoms in a nanoparticle at a specific point in its growth,” says Mary Scott, who conducted the research. “This will help us learn how nanoparticles grow atom by atom, and it sets the stage for a materials-design approach starting from the smallest building blocks.”

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Nano-chimney to Cool Circuits

Overheating has emerged as a primary concern in the development of new electronic devices. A new study from Rice University looks to provide a solution to that, offering a strategy to vent heat away from nano-electronics through cone-like chimneys.

By putting these “chimneys” between the graphene and nanotube, the researchers effectively eliminate a barrier that typically blocks heat from escaping.

This from Rice University:

Researchers at Rice University discovered through computer simulations that removing atoms here and there from the two-dimensional graphene base would force a cone to form between the graphene and the nanotube. The geometric properties of the graphene-to-cone and cone-to-nanotube transitions require the same total number of heptagons, but they are more sparsely spaced and leave a clear path of hexagons available for heat to race up the chimney.

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Detecting Disease Through Your Breath

One of the major challenges in modern medicine is how to accurately detect disease when people are still feeling healthy. Researchers and doctors alike have long since wondered how to diagnose diseases such as cancer before it progresses too far.

Now, the medical community may find that answer in a new development out of Technion – Israel Institute of Technology called the Na-Nose.

The Na-Nose is a newly developed device that can analyze the chemical signature of exhaled gases to diagnose diseases with 86 percent accuracy. The science behind the device uses carbon nanotubes and gold particles to isolate volatile biomarkers in a patient’s breath.

Researchers then used a computer algorithm to recognize the biomarkers, creating a tool that can quickly and accurately detect diseases such as ovarian cancer or multiple sclerosis in early stages without any invasive procedures.

“It works in the same way we’d use dogs in order to detect specific compounds,” Hossam Haick, co-author of the study, told Smithsonian. “We bring something to the nose of a dog, and the dog will transfer that chemical mixture to an electrical signature and provide it to the brain, and then memorize it in specific regions of the brain … This is exactly what we do. We let it smell a given disease but instead of a nose we use chemical sensors, and instead of the brain we use the algorithms. Then in the future, it can recognize the disease as a dog might recognize a scent.”

By: Sameer Sonkusale, Tufts University

Nanowires

Image: Alonso Nichols, Tufts University, CC BY-ND

Doctors have various ways to assess your health. For example, they measure your heart rate and blood pressure to indirectly assess your heart function, or straightforwardly test a blood sample for iron content to diagnose anemia. But there are plenty of situations in which that sort of monitoring just isn’t possible.

To test the health of muscle and bone in contact with a hip replacement, for example, requires a complicated – and expensive – procedure. And if problems are found, it’s often too late to truly fix them. The same is true when dealing with deep wounds or internal incisions from surgery.

In my engineering lab at Tufts University, we asked ourselves whether we could make sensors that could be seamlessly embedded in body tissue or organs – and yet could communicate to monitors outside the body in real time. The first concern, of course, would be to make sure that the materials wouldn’t cause infection or an immune response from the body. The sensors would also need to match the mechanical properties of the body part they would be embedded in: soft for organs and stretchable for muscle. And, ideally, they would be relatively inexpensive to make in large quantities.

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Remembering Harry Kroto

Harry KrotoA giant among giants

Harry Kroto, distinguished chemist and pioneering nanocarbons researcher, passed away on April 30, 2016 at the age of 76. Kroto, a giant among giants, made an immense impact not only on ECS and its scientific discipline – but the world at large.

“Harry Kroto’s passing is a great loss to science and society as a whole,” says Bruce Weisman, professor at Rice University and division chair of the ECS Nanocarbons Division. “He was an exceptional researcher whose 1985 work with Rick Smalley and Bob Curl launched the field of nanocarbons research and nanotechnology.”

Revolutionizing chemistry

That work conducted by Kroto, Smalley, and Curl yielded the discovery of the C60 structure that became known as the buckminsterfullerene (or the “buckyball” for short). Prior to this breakthrough, there were only two known forms of pure carbon: graphite and diamond. The work opened a new branch in chemistry with unbound possibilities, earning the scientists the 1996 Nobel Prize in Chemistry.

The field of nanocarbons and fullerenes, since the discovery by Kroto and company, has evolved into an area with almost limitless potential. The applications for this scientific discipline are wide-ranging – from energy harvesting to sensing and biosensing to biomedical applications and far beyond. Research in this field continues to fill the pages of scholarly journals, making possible innovations that were not even conceived before the seminal 1985 work.

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Improving Energy Storage

Nanoparticles have been central to many recent developments, including computing, communications, energy, and biology. However, because nanoparticles are hard to observe, it’s often difficult to pick the best shapes and sizes to perform specific tasks at optimal capacity.

That may be a problem no longer thanks to research out of Stanford University, where researchers gazed inside phase-changing nanoparticles for the first time – allowing them to understand how shape and crystallinity can have dramatic effects on performance.

Practically, this means that the design of energy storage materials could begin to change.

Take the lithium-ion battery, which stores and releases energy due to the electrode’s ability to sustain large deformations over several charge and discharge cycles without degrading. By nanosizing the electrode, researchers recently improved upon the efficiency process.

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Nanostructures

Nanostructures on the surface of the fabric.
Image: Queensland University of Technology

Oil spills have had an extensive history of disrupting the environment, killing ecosystems, and displacing families. Impacts of massive oil spills are still felt in many parts of the world, including the undersea spill at the BP oil rig in the Gulf of Mexico that dumped an approximate 39 million gallons of oil into the gulf.

But what if these devastating oil spills could be easily cleaned up with a piece of fabric rooted in electrochemistry?

That may be a reality soon thanks to researchers at Queensland University of Technology (QUT). According to a release, the QUT researchers have developed a multipurpose fabric covered with semi-conducting nanostructures that can both mop up oil and degrade organic matter when exposed to light.

(READ: “Superhydrophobic Fabrics for Oil/Water Separation Based on the Metal-Organic Charge-Transfer Complex CuTCNAQ“)

The fabric, which repels water and attracts oil, has already has promising preliminary results. In the early stages of research, the scientists have already been able to mop up crude oil from the surface of both fresh and salt water.

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