Tuesday, 05 November 2013.
Source: SciTech Digest 38
A Top 10 selection of scientific and technological advances each week compiled by ITEK's Commercial Manager Mark Bruce.
1. One-Dimensional Electrical Contacts for Two-Dimensional Graphene.
The first edge-on one-dimensional electrical contact with graphene has been demonstrated http://spectrum.ieee.org/nanoclast/semiconductors/nanotechnology/engineers-make-electrical-contact-to-graphene-on-its-1-atom-thick-edge . Conventional approaches typically place the electrical contacts on the top surface of graphene sheets, which can multi-material layering difficult and complicated. This new approach allows electrical contacts to the atom-thick edges of graphene sheets and also multi-material stacked sheets such as graphene interleaved with sheets of boron-nitride. This also results in lower contact resistance compared to other approaches.
2. Complex Multi-Functional Particles for Cell Treatments.
A new type of particle has been fabricated from a wide variety of materials and nanostructures that enables remote detection, diagnosis, and drug delivery to cancerous and other cells of interest http://www.uc.edu/news/NR.aspx?id=18622 . The particles can carry fluorescent molecules for imaging, transport cell-surface detection molecules, carry and deliver drugs and other molecules, and most importantly carry multiple components in a single assembly and function in a programmed manner thanks to functionally and distinct chemically surfaces. It will be good to follow the in vivo studies and it is promising to see such systems achieving greater complexity.
3. Narrow Software AI Breaks CAPTCHAs.
Narrow artificial intelligence software developed by Vicarious has been demonstrated to accurately and quickly solve CAPTCHAs, those image-word games used by websites to allow humans access but block bots http://www.kurzweilai.net/vicarious-ai-breaks-captcha-turing-test . Some consider CAPTCHA schemes broken if an algorithm can determine the correct answer 1% of the time; Vicarious’ system routinely achieves accuracies greater than 90% and so renders CAPTCHAs no longer effective. The system is elegant, combining insights from machine learning and neuroscience, utilising miniscule amounts of data and computation, and achieves levels of effectiveness and efficiency much closer to human brains. Such visual perception software could find incredible broad uses in the years to come.
4. Peptoid Velcro: Antibody Mimic.
Nanosheet scaffolds assembled from structurally-programmed peptoids (synthetic polymers that can fold like proteins) that form little functional loops can mimic the precise molecular-binding capabilities of natural antibodies http://phys.org/news/2013-10-molecular-velcro-cost-effective-alternatives-natural.html . Inserting short molecular segments into the loop-forming peptoids creates functional loops that can be selectively programmed to bind enzymes, inorganic materials, or other molecules - which enables a fantastically versatile platform for creating biosensors and catalysts for example. These peptoid materials can be made in very high yields and can withstand harsh environmental conditions.
5. Utilising Electricity-Producing Bacteria.
Work on microbial-electrode catalysts with dissimilatory metal-reducing bacteria indicate that relatively large amounts of electrical energy can be produced from seawater, carbon dioxide, and sunlight http://phys.org/news/2013-10-energy-bacteria.html . As an example demonstration, a thick biofilm of a certain species of bacteria was grown on the surface of an electrode; the bacteria acquire energy by coupling the oxidation of organic material with the reduction of insoluble metal oxidants, with electrons being transported through the extracellular biofilm to the electrode surface to generate a current. I wonder whether an implantable device based on this system might be able to power other implanted devices.
6. Super-Efficient Electro-Osmotic Pumps.
A new miniaturised electroosmotic pump is based on a silicon nanomembrane and can be used to move solutions through microfluidic channels up to 40 times more efficient than other similar pumps http://www.eurekalert.org/pub_releases/2013-10/uor-smc102813.php . The membranes are 15nm-thick porous nanocrystalline silicon, allow electrodes to be placed closer together, are cheap to make, and can easily be incorporated into a range of microfluidic chip architectures. Key applications are portable devices for sensing and diagnostic uses, although the low-powered movement of cooling fluids could also find uses in cooling computer chips - like those from IBM last week.
7. Sophisticated DNA Sequencing with Graphene Nanopores.
There have been a number of designs and tests over the past couple of years for graphene nanopores to sequence strands of DNA. This latest effort consists of a more sophisticated design in which the electrical properties of the graphene can be tuned and the rotational and positional conformation of the DNA strand can be determined http://phys.org/news/2013-10-nanopore-ionically-graphene-quantum-transistor.html . It will be good to see the group reduce what is essentially a graphene-based field-effect transistor to practice and derive actual DNA sequence information. They plan to incorporate additional two-dimensional materials for added control, propose that future control (not just sensing) of biological molecules may be possible, and in general demonstrate the increasing complexity of molecular modelling programs. Graphene also allows switchable bio-interfaces http://www.nanowerk.com/spotlight/spotid=33004.php .
8. New Circuit Doubles Wireless Bandwidth.
New company Kumu Networks has launched a circuit and algorithm that allows wireless data to be sent and received on the same frequency http://www.technologyreview.com/news/520586/the-clever-circuit-that-doubles-bandwidth/ . This potentially enables wireless bandwidth to double in certain applications, with field trials planned with major carriers next year. The circuit predicts how much self-interference the transmitter is about to create, then generates a signal to cancel it out - thus allowing receiving data to be heard. This is the first time this has been possible with mobile and WiFi applications.
9. Nanoparticle Light Filter for Boosting Algae.
Gold and silver nanoparticles have been used as an optical nanofilter that provides the wavelengths of light that are most useful to algae growth and production while blocking wavelengths that are harmful http://phys.org/news/2013-10-nanofilter-worth-weight-gold-silver.html . Algal production of biofuels and other materials is a hot area right now and it is great to have additional ways of boosting production in addition to the usual genetic engineering approaches. Other applications include artificial photosynthesis for improved hydrogen production.
10. Rapid Scalable Synthesis of Quantum Dots.
Researchers have developed a scalable, continuous-flow, two-stage synthesis process to produce high quality quantum dot nanocrystals http://www.nanowerk.com/spotlight/spotid=32945.php . Synthesis typically involves nucleation and growth phases, but these demand different temperature conditions and is something that batch processes struggle with. The new system works with microfluidics to precisely mix starting materials, and control nucleation and growth in separate spaces - this produces results as good as the best batch process but which is also low-cost, mass-producible, and automated. Such control allows quantum dots with nearly any desired property to be produced for a huge range of applications - a potentially transformative capability and yet another demonstration of the power of adding modularity to technological systems.