Scientists have been able to manufacture 3-D isotropic metamaterials, but up to now only on a very small scale. Now, in a significant breakthrough, scientists from RIKEN, in collaboration with colleagues in Taiwan, have succeeded in creating a large metamaterial up to 4-mm-square in size that is essentially isotropic, using a type of metamaterial element called a split-ring resonator.
A few short years ago, the idea of a practical manufacturing process based on getting molecules...
Several types of plastic pipes in eco-friendly green buildings in the U.S. have been found to...
An emerging class of electrically conductive plastics called "radical polymers” may bring low-cost, transparent solar cells, flexible and lightweight batteries, and ultrathin antistatic coatings for consumer electronics and aircraft. Researchers have established the solid-state electrical properties of one such polymer, called PTMA, which is about 10 times more electrically conductive than common semiconducting polymers.
Platelets, the tiny cell fragments whose job it is to stop bleeding, are very simple. They don’t have a cell nucleus. But they can “feel” the physical environment around them, researchers at Emory Univ. and Georgia Tech have discovered. Platelets respond to surfaces with greater stiffness by increasing their stickiness, the degree to which they “turn on” other platelets and other components of the clotting system, the researchers found.
Researchers are developing a robotic fabric that moves and contracts and is embedded with sensors, an approach that could lead to "active clothing" or a new class of "soft" robots. The robotic fabric, developed at Purdue Univ., is a cotton material containing sensors made of a flexible polymer and threadlike strands of a shape-memory alloy that return to a coiled shape when heated, causing the fabric to move.
A collaboration between scientists in the Univ. of Chicago’s chemistry department, the Institute for Molecular Engineering and Argonne National Laboratory has produced the highest-ever recorded efficiency for solar cells made of two types of polymers and fulllerene. Researchers identified a new polymer that improved the efficiency of solar cells and also determined the method by which the polymer improved the cells’ efficiency.
Researchers from the Univ. of Cambridge have developed advanced molecular synthetic membranes, or “sieves”, which could be used to filter carbon dioxide and other greenhouse gases from the atmosphere. The sieves were made by heating microporous polymers using low levels of oxygen which, produces a tougher and far more selective membrane that is still relatively flexible.
When Orlando Rios first started analyzing samples of carbon fibers made from a woody plant polymer known as lignin, he noticed something unusual. The material’s microstructure—a mixture of perfectly spherical nanoscale crystallites distributed within a fibrous matrix—looked almost too good to be true.
For future astronauts, the process of suiting up may go something like this: Instead of climbing into a conventional, bulky, gas-pressurized suit, an astronaut may don a lightweight, stretchy garment, lined with tiny, muscle-like coils. She would then plug in to a spacecraft’s power supply, triggering the coils to contract and essentially shrink-wrap the garment around her body.
Cephalopods are among nature’s most skillful camouflage artists, able to change both the color and texture of their skin within seconds to blend into their surroundings. Engineers have long struggled to duplicate this in synthetic materials. Now a team of researchers has come closer than ever to achieving that goal, creating a flexible material that can change its color or fluorescence and its texture at the same time.
Plastics are made of polymers, which are a challenge for scientists to study. Their chain-like strands of thousands of atoms are tangled up in a spaghetti-like jumble, their motion can be measured at many time scales and they are essentially invisible to some common x-ray study techniques. A better understanding of polymers at the molecular scale could lead to improved manufacturing techniques and the creation of new materials.
For detecting cancer, manual breast exams seem low-tech compared to other methods such as MRI. But scientists are now developing an “electronic skin” that “feels” and images small lumps that fingers can miss. Knowing the size and shape of a lump could allow for earlier identification of breast cancer, which could save lives.
Polymers come with a range of properties dictated by their chemical composition and geometrical arrangement. Yasuyuki Tezuka and his team at Tokyo Institute of Technology have now applied an approach to synthesize a new type of multicyclic polymer geometry. While mathematicians are interested because these structures have not been realized before, the geometry studies also provide insights for chemists.
Injuries, birth defects (such as cleft palates) or surgery to remove a tumor can create gaps in bone that are too large to heal naturally. And when they occur in the head, face or jaw, these bone defects can dramatically alter a person’s appearance. Researchers have developed a “self-fitting” material that expands with warm salt water to precisely fill bone defects, and also acts as a scaffold for new bone growth.
Wrapping wound dressings around fingers and toes can be tricky, but for burn victims, guarding them against infection is critical. At the National Meeting & Exposition of the American Chemical Society scientists have reported the development of new ultra-thin coatings called nanosheets that can cling to the body's contours and keep bacteria at bay. The super-thin sheets have been tested on mice and could help transform burn treatment.
An outline of Marilyn Monroe's iconic face appeared on the clear, plastic film when a researcher fogs it with her breath. Terry Shyu, a doctoral student in chemical engineering at the Univ. of Michigan, was demonstrating a new high-tech label for fighting drug counterfeiting. While the researchers don't envision movie stars on medicine bottles, they used Monroe's image to prove their concept.
Long before humans figured out how to create colors, nature had already perfected the process. Now scientists are tapping into those secrets to develop a more environmentally friendly way to make colored plastics. Their paper on using structure—or the shapes and architectures of materials—rather than dyes, to produce color appears in Nano Letters.
Rice Univ. researchers are using magnetic beads and DNA “springs” to create chains of varying flexibility that can be used as microscale models for polymer macromolecules. The experiment is visual proof that “bead-spring” polymers, introduced as theory in the 1950s, can be made as stiff or as flexible as required and should be of interest to materials scientists who study the basic physics of polymers.
Highly purified crystals that split light with precision are valued in specialized optics. But photonic crystals are difficult to make with current techniques, namely electron beam etching. Researchers at Princeton and Columbia universities have proposed a new method derived from colloidal suspensions that could allow scientists to customize and grow optimal crystals with relative ease.
Marilyn Minus, a materials expert and assistant professor at Northeastern Univ., is exploring directed self-assembly methods using carbon nanotubes and polymer solutions. So far, she’s used the approach to develop a polymer composite material that is stronger than Kevlar yet much lighter and less expensive. Minus is now expanding this work to incorporate more polymer classes: flame retardant materials and biological molecules.
Plastic junk is floating widely on the world's oceans, but there's less of it than expected, a study says. A newly published study drew on results from an around-the-world cruise by a research ship that towed a mesh net at 141 sites, as well as other studies. Researchers estimated the total amount of floating plastic debris in open ocean at 7,000 to 35,000 tons.
In wind farms across North America and Europe, sleek turbines equipped with state-of-the-art technology convert wind energy into electric power. But tucked inside the blades of these feats of modern engineering is a decidedly low-tech core material: balsa wood.
Superlyophobic surfaces are simultaneously repellant for almost any liquid and exhibit high contact angles and low flow resist. But the demanding and usually expensive fabrication remains a bottleneck for further development. Researchers in Shenzhen, China, however, have now formulated a facile and inexpensive microfabrication method that uses polymers to help transfer the superlyophobic structures to curable materials.
Since the early 1970s, lithium has been the most popular element for batteries because of it’s low weight and good electrochemical potential. But it is also highly flammable. Researchers have recently married two traditional theories in materials science that can explain how the charge dictates the structure of the material. And using this they may be able to move to other materials, such as block copolymers, for use in batteries.
A new nanoparticle platform developed in California increases the efficiency of drug delivery and allows excess particles to be washed away. A simple etching technique using biocompatible chemicals rapidly disassembles and removes the silver nanoparticles outside living cells. This method leaves only the intact nanoparticles for imaging or quantification, revealing which cells have been targeted and how much each cell internalized.
When stem cells are used to regenerate bone tissue, many wind up migrating away from the repair site, which disrupts the healing process. But a technique employed by a Univ. of Rochester research team keeps the stem cells in place, resulting in faster and better tissue regeneration. The keyis encasing the stem cells in polymers that attract water and disappear when their work is done.
Polymer scientists in Ohio have demonstrated how a transparent layer of electrodes on a polymer surface could be extraordinarily tough and flexible, withstanding repeated scotch tape peeling and bending tests. According to its developers, the new material could replace conventional indium tin oxide coatings currently used for touchscreens.
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