Philip Ball, Science Writer explains to SPTNK the future of chemistry. We need to look beyond the periodic table and focus on the relationship between molecules.
Archive for the ‘M is for Micron’ Category
Andre K. Geim and Konstantin S. Novoselov, winners of Nobel Prize in Physics. Photos by University of Manchester, via Associated Press
The 2010 Nobel Prize for Physics was won by two scientists for their work on a revolutionary ultra-thin material called graphene, the Royal Swedish Academy of Sciences announced.
The breakthrough has implications for areas from quantum physics to consumer electronics.
Andre K. Geim and Konstantin S. Novoselov, both scientists at the University of Manchester in England, shared the award for their development of a form of carbon that is only one atom thick.
In their announcement of the prize, the Academy said that “carbon in such a flat form has exceptional properties that originate from the remarkable world of quantum physics.”
Photo via flickr by jcdoll
The challenge in the nano world is how to provide power to nanoscale sensors, which need power to operate, for example, implantable medical devices and serve as tiny sensors and detectors. Zhong Lin Wang, a materials scientist at Georgia Tech, thinks he can bring power to the nano world with minuscule generators that take advantage of piezoelectricity, in which crystalline materials under mechanical stress produce an electrical potential. If he succeeds, biological and chemical nano sensors will be able to power themselves.
While the piezoelectric effect has been known of for more than a century, in 2005, Wang was the first to demonstrate it at the nanoscale by bending zinc oxide nanowires with the probe of an atomic-force microscope. As the wires flex and return to their original shape, the potential produced by the zinc and oxide ions drives an electrical current. The current that Wang coaxed from the wires in his initial experiments was tiny; the electrical potential peaked at a few millivolts. But Wang rightly suspected that with enough engineering, he could design a practical nanoscale power source by harnessing the tiny vibrations all around us – sound waves, the wind, even the turbulence of blood flow over an implanted device. These subtle movements would bend nanowires, generating electricity.
Wang embedded zinc oxide nanowires in a layer of polymer; the resulting sheets put out 50 millivolts when flexed. This is a major step forward in powering tiny sensors.
And Wang hopes that these generators could eventually be woven into fabric; the rustling of a shirt could generate enough power to charge the batteries of devices like iPods. For now, the nanogenerator’s output is too low for that. “We need to get to 200 millivolts or more,” says Wang. He’ll get there by layering the wires, he says, though it might take five to ten more years of careful engineering.
Meanwhile, Wang has demonstrated the first components for a new class of nanoscale sensors. Nanopiezotronics, as he calls this technology, exploit the fact that zinc oxide nanowires not only exhibit the piezoelectric effect but are semiconductors. The first property lets them act as mechanical sensors, because they produce an electrical response to mechanical stress. The second means that they can be used to make the basic components of integrated circuits, including transistors and diodes. Unlike traditional electronic components, nanopiezotronics don’t need an external source of electricity. They generate their own when exposed to the same kinds of mechanical stresses that power nanogenerators.
Freeing nanoelectronics from outside power sources opens up all sorts of possibilities. A nano piezotronic hearing aid integrated with a nanogenerator might use an array of nanowires, each tuned to vibrate at a different frequency over a large range of sounds. The nanowires would convert sounds into electrical signals and process them so that they could be conveyed directly to neurons in the brain. Not only would such implanted neural prosthetics be more compact and more sensitive than traditional hearing aids, but they wouldn’t need to be removed so their batteries could be changed. Nanopiezotronic sensors might also be used to detect mechanical stresses in an airplane engine; just a few nanowire components could monitor stress, process the information, and then communicate the relevant data to an airplane’s computer. Whether in the body or in the air, nano devices would at last be set loose in the world all around us.
Photo via flickr by all-i-oli
If researchers at Fudan University in Shanghai are right, we may all someday possess Harry Potter’s invisibility cloak. The theorists believe that silver-plated nanoparticles suspended in water and aligned in a magnetic field could allow for creating a metamaterial—the “active ingredient” in an invisibility device.
The fluid proposed by Ji-Ping Huang and colleagues of Fudan University contains magnetite balls 10 nanometres in diameter, coated with a 5-nanometre-thick layer of silver, possibly with polymer chains attached to keep them from clumping.
In the absence of a magnetic field, such nanoparticles would simply float around in the water, but if a field were introduced, the particles would self-assemble into chains whose lengths depend on the strength of the field, and which can also attract one another to form thicker columns.
The chains and columns would lie along the direction of the magnetic field. If they were oriented vertically in a pool of water, light striking the surface would refract negatively—bent in a way that no natural material can manage.
This property could be exploited for invisibility devices, directing light around an object so that it appears as if nothing is there, or be put to use in lenses that could capture finer details than any optical microscope.
This isn’t the first attempt at building an invisibility device. David Smith and his team at Duke University in September 2006 had built a device that could hide an object from view, but only from the “eyes” of a microwave detector—and then only at a very specific microwave frequency.
Photo via flickr by ashe-villain
From soils and sediments, to chunks of pavement, archaeological remains and chocolate bars—the Nanotom, the most advanced 3D X-ray micro Computed Tomography (CT) scanner in the world, will help scientists at The University of Nottingham literally see through solids. The machine will make previously difficult and laborious research much easier as it allows researchers to probe inside objects without having to break into them.
Part of a new project in the School of Biosciences to scan soil samples for research into soil-plant interactions, the Nanotom by GE Sensing and Inspection Technology is a very powerful tool that allows us to see the internal structure of an object that might be otherwise hidden from view.
The first project of the Nanotom will be to examine the sensing ability of roots to grow in the best direction for the health of the plant through the soil. It aims to provide evidence of how the root reacts and adapts to soil stresses like drought and compaction by adjusting the genetic information in the tips of the root as it grows. The Nanotom will allow researchers to follow the progress of the root growth and soil structural development for the first time without disturbing the sample of the plant growing in the soil.
The eventual aim of research like this is to contribute to worldwide efforts for food security and sustainable food production by preserving and improving the vital but finite soil resources of the planet. It will enable scientists to come up with a recipe for the best soil composition and level of compaction, as well as informing plant breeding programs. Accurate soil structure measurement will be also be essential in changing farming practices to cut CO2 which is released into the atmosphere during traditional ploughing of agricultural soil.
via Science Daily
The atom used to be the iconic symbol of our world. Now it’s about going inside the atom to experience the world at the nanoscale, where everything is in motion. Because the aesthetic at the nanoscale is like sticking your head inside a pixel. In fact, if you use a scanning electron microscope, as did artists AE Lab, you can travel from 200 magnification to about 500 nanometers in real-time, so fast it’ll trigger a zooming sensation. And, since you’re watching quantum dynamic interactions occur at the molecular level, you’ll never see the same thing twice. This is the land of the infinitely small, it’s the burgeoning field of nanoart and what science has hailed as the next big thing. And whether it’s nanomedicine or self-assembly in material science, many of tomorrow’s advancements will happen at the phenomenon of scale. Even the architecture of the future will be one of making tiny moves. Dubbed micro-environmental design, the drive is to replace today’s single grid mentality where everything is networked together with systems that are democratic, allowing technologies to operate and connect independently so that spaces, for instance, don’t have to be determined by the same temperature, lighting or ventilation constraints, but rather offer micro-climatic conditions for a field of choice. One aim, in particular, being led by architect and engineer Michelle Addington, is the desire to control thermal behavior. Addington’s great hope is to allow energies to maintain their autonomous thermal boundary layers so that designers can completely control what’s going on in any surface, no matter what the material or circumstance so, for instance, a thin piece of glass can behave like a thick wall. In tomorrow’s lifestyles of the tiny, whether its micronutrients that are absorbed by copper bracelets or the hope of self-organizing nano-computers that can shapeshift on the fly, the key phrase is: Welcome to microworld, Na-Nu, Na-Nu.