A strain-sensing smart skin developed at Rice University that uses very small structures, carbon nanotubes, to monitor and detect damage in large structures is ready for prime time.
The ‘strain paint’ first revealed by Rice in 2012 uses the fluorescent properties of nanotubes to show when a surface has been deformed by stress.
A strain-sensing smart skin developed at Rice University that uses very small structures, carbon nanotubes, to monitor and detect damage in large structures is ready for prime time.
The “strain paint” first revealed by Rice in 2012 uses the fluorescent properties of nanotubes to show when a surface has been deformed by stress.
Continue reading “Strain-sensing smart skin ready to deploy” »
Korea Advanced Institute of Science and Technology (KAIST) researchers and their collaborators at home and abroad have successfully demonstrated a new platform for guiding the compressed light waves in very thin van der Waals crystals. Their method to guide the mid-infrared light with minimal loss will provide a breakthrough for the practical applications of ultra-thin dielectric crystals in next-generation optoelectronic devices based on strong light-matter interactions at the nanoscale.
Phonon-polaritons are collective oscillations of ions in polar dielectrics coupled to electromagnetic waves of light, whose electromagnetic field is much more compressed compared to the light wavelength. Recently, it was demonstrated that the phonon-polaritons in thin van der Waals crystals can be compressed even further when the material is placed on top of a highly conductive metal. In such a configuration, charges in the polaritonic crystal are “reflected” in the metal, and their coupling with light results in a new type of polariton waves called the image phonon-polaritons. Highly compressed image modes provide strong light-matter interactions, but are very sensitive to the substrate roughness, which hinders their practical application.
Challenged by these limitations, four research groups combined their efforts to develop a unique experimental platform using advanced fabrication and measurement methods. Their findings were published in Science Advances on July 13.
The discovery could inform the design of practical superconducting devices.
When it comes to graphene.
Graphene is an allotrope of carbon in the form of a single layer of atoms in a two-dimensional hexagonal lattice in which one atom forms each vertex. It is the basic structural element of other allotropes of carbon, including graphite, charcoal, carbon nanotubes, and fullerenes. In proportion to its thickness, it is about 100 times stronger than the strongest steel.
Motors are everywhere in our day-to-day lives—from cars to washing machines. A futuristic scientific field is working on tiny motors that could power a network of nanomachines and replace some of the power sources we use in devices today.
In new research published recently in ACS Nano, researchers from the Cockrell School of Engineering at The University of Texas at Austin created the first ever solid-state optical nanomotor. All previous versions of these light-driven motors reside in a solution of some sort, which held back their potential for most real-world applications.
Brain-machine interfaces (BMIs) are devices that enable direct communication/translation between biological neuronal networks (e.g. a brain or a spine) and external machines. They are currently being used as a tool for fundamental neuroscience research and also for treating neurological disorders and for manipulating neuro-prosthetic devices. As remarkable as today’s BMIs are, however, the next generation BMIs will require new hardware and software with improved resolution and specificity in order to precisely monitor and control the activities of complex neuronal networks. In this talk, I will describe my group’s effort to develop new neuroelectronic devices enabled by silicon nanotechnology that can serve as high-precision, highly multiplexed interface to neuronal networks. I will then describe the promises, as well as potential pitfalls, of next generation BMIs. Hongkun Park is a Professor of Chemistry and Chemical Biology and a Professor of Physics at Harvard University. He is also an Institute Member of the Broad Institute of Harvard and MIT and a member of the Harvard Center for Brain Science and Harvard Quantum Optics Center. He serves as an associate editor of Nano Letters. His research interests lie in exploring solid-state photonic, optoelectronic, and plasmonic devices for quantum information processing as well as developing new nano-and microelectronic interfaces for living cells, cell networks, and organisms. Awards and honors that he received include the Ho-Am Foundation Prize in Science, NIH Director’s Pioneer Award, and the US Vannevar Bush Faculty Fellowship, the David and Lucile Packard Foundation Fellowship for Science and Engineering, the Alfred P. Sloan Research Fellowship, and the Camille Dreyfus Teacher-Scholar Award. This talk was given at a TEDx event using the TED conference format but independently organized by a local community.
As our devices get smaller and smaller, the use of molecules as the main components in electronic circuitry is becoming ever more critical. Over the past 10 years, researchers have been trying to use single molecules as conducting wires because of their small scale, distinct electronic characteristics, and high tunability. But in most molecular wires, as the length of the wire increases, the efficiency by which electrons are transmitted across the wire decreases exponentially. This limitation has made it especially challenging to build a long molecular wire—one that is much longer than a nanometer—that actually conducts electricity well.
Columbia researchers announced today that they have built a nanowire that is 2.6 nanometers long, shows an unusual increase in conductance as the wire length increases, and has quasi-metallic properties. Its excellent conductivity holds great promise for the field of molecular electronics, enabling electronic devices to become even tinier. The study is published today in Nature Chemistry.
Under the direction of Latha Venkataraman, associate professor of applied physics at Columbia Engineering, researchers have designed a new technique to create a single-molecule diode, and, in doing so, they have developed molecular diodes that perform 50 times better than all prior designs. Venkataraman’s group is the first to develop a single-molecule diode that may have real-world technological applications for nanoscale devices. Their paper, “Single-Molecule Diodes with High On-Off Ratios through Environmental Control,” is published May 25 in Nature Nanotechnology.
“Our new approach created a single-molecule diode that has a high (250) rectification and a high “on” current (~ 0.1 micro Amps),” says Venkataraman. “Constructing a device where the active elements are only a single molecule has long been a tantalizing dream in nanoscience. This goal, which has been the ‘holy grail’ of molecular electronics ever since its inception with Aviram and Ratner’s 1974 seminal paper, represents the ultimate in functional miniaturization that can be achieved for an electronic device.”
With electronic devices becoming smaller every day, the field of molecular electronics has become ever more critical in solving the problem of further miniaturization, and single molecules represent the limit of miniaturization. The idea of creating a single-molecule diode was suggested by Arieh Aviram and Mark Ratner who theorized in 1974 that a molecule could act as a rectifier, a one-way conductor of electric current. Researchers have since been exploring the charge-transport properties of molecules. They have shown that single-molecules attached to metal electrodes (single-molecule junctions) can be made to act as a variety of circuit elements, including resistors, switches, transistors, and, indeed, diodes. They have learned that it is possible to see quantum mechanical effects, such as interference, manifest in the conductance properties of molecular junctions.
Evolution has developed very efficient molecular machines, for example for producing energy through rotation. Hendrik Dietz would like to harness these concepts to build his own molecular motors. His group has successfully demonstrated that they can encode and synthesize complex shapes using DNA origami, and have recently discovered how to reduce the cost for mass use and production. With his research, Dietz gets closer to his goal of revolutionizing nanotechnology with the capabilities of molecular motors, just like industry was revolutionized by electric and diesel motors.
. Can you remember playing with legos? Now imagine doing that with molecules. Prof. Hendrik Dietz, professor for experimental biophysics at TUM, runs a lab which does just that. Inspired by the rich functionalities of natural macromolecular assemblies such as enzymes, molecular motors, and viruses, the Dietz lab investigates how to build increasingly complex molecular structures. The goal is to build molecular devices and machines that can execute user-defined tasks. DNA origami in particular enables building nanodevices that can already be employed for making new discoveries in biomolecular physics and protein science. This talk was given at a TEDx event using the TED conference format but independently organized by a local community.
The basic design of the toothbrush hasn’t changed in a thousand years — sure, there are motors, different materials, and funky shapes, but they’re all still sticks with bristles attached. A team from the University of Pennsylvania believes it’s time to shake things up. In a new study, the researchers have shown that shapeshifting nanoparticles can successfully clean teeth, replacing all the manual labor with a nano-scale robotic dance. Not only can these particles be transformed into tooth-cleaning shapes, but their action can have antimicrobial effects that destroy plaque-causing bacteria.
This project came together quite by accident. A group from the Penn School of Dental Medicine under professor Hyun (Michel) Koo was interested in leveraging the catalytic activity of nanoparticles to release free radicals that could kill microbes on the teeth. Meanwhile, senior engineering researcher Edward Steagar was spearheading work at the Penn School of Engineering and Applied Sciences on assembling nanoparticles into robots. Bringing these projects together gave us the sci-fi gray goo toothbrush.
The combined team used magnetic fields to manipulate iron oxide nanoparticles, testing them first on a slab of tooth-like material. Next, the team moved to 3D-printed copies of teeth. Finally, they tested the nanoparticle brushes on real teeth that were mounted in a realistic way to simulate a human mouth. The tests show these nanoparticles can form brush-like shapes capable of scrubbing off the biofilms that lead to tooth decay. They can also flow between teeth like floss. All the while, the nanoparticles promote the production of free radicals that further eliminate bacteria.
