Showing Spotlights 1337 - 1344 of 2428 in category All (newest first):
Bacterial propulsion systems are intriguing for nanotechnology researchers because nature has already solved most of the problems that they are still struggling with in designing molecular motors and other self-sustained nanoscale actuating systems. Indeed, it has turned out to be very challenging to even move sub-micron scale structures in well directed paths, especially under biologically friendly conditions. In previous work, researchers have already shown how large numbers of bacteria can propel larger sub-mm scale structures. And in a 2005 paper, researchers demonstrated a method of using the power generated by biological motors to transport microscale loads while leaving these motors in intact cells. Scientists at Johns Hopkins University have now demonstrated a strategy to autonomously move nanostructures in well defined paths by enabling individual bacteria-cargo conjugates. They showed how approximately 500 nm-sized structures deposited on substrates can be attached to individual bacteria and when released, the bacteria stay motile and ferry this cargo.
Mar 1st, 2011
Quantum dots, because they are both photoluminescent and electroluminescent and have unique physical properties, will be at the core of next-generation displays. Compared to organic luminescent materials used in organic light emitting diodes (OLEDs), QD-based materials have purer colors, longer lifetime, lower manufacturing cost, and lower power consumption. Another key advantage is that, because QDs can be deposited on virtually any substrate, you can expect printable and flexible displays of all sizes. To date, the integration of QDs into a full-color LED structure has not been possible due to the difficulty in patterning individual red-green-blue (RGB) QDs onto the pixelated display panel. Now, a Samsung team has demonstrated a novel transfer printing approach which enables fine patterning of high-quality QD films for large-area (4-inch diagonal), full-color displays mounted on glass as well as on flexible plastic substrates.
Feb 28th, 2011
A Single Nucleotide Polymorphism (SNP) is a single nucleotide replacement in a DNA sequence - occurring when a single nucleotide (A, T, C, or G) in the genome differs - which can result in different reaction by people to pathogens and medicines. Detection of these SNPs is becoming increasingly important with the move towards more personalized healthcare. Researchers are therefore working hard in developing biomedical lab-on-chip sensors that allow the fast detection of SNPs in DNA using only very small samples of a patient's blood. Already, nanoscale detection techniques such as synthetic nanochannels are being used for DNA detection by specific DNA hybridization with molecular probes immobilized on the nanochannel walls. However, the preparation of these sensors is not easy and specific functionalization at the wall surface remains a critical issues. Researchers have now introduced a new concept of DNA-based molecular recognition agents which allows detecting SNPs with very high precision and efficiency.
Feb 25th, 2011
Researchers are faced with a paradox in quantum dot-based particle/molecule tracking: on one hand, blinking is a problem for quantum dot-based tracking as it breaks up tracking trajectories; on the other hand, blinking is also a very useful indicator as it offers the best - and often only practical - in situ indication of aggregation status. Thus, when a researcher conducts a tracking experiment, s/he is annoyed by blinking but at the same time would be equally disappointed if blinking was not present to confirm single, or near single, particle status. Previous strategies to manipulate blinking dynamics involve changing the structure (surface or core chemistry) of a quantum dot. Scientists have now taken a fundamentally different approach: quantum dots employed remain unchanged.
Feb 24th, 2011
Research to develop sensors that can rapidly detect biomarkers (associated with certain diseases such as cancer) in whole blood, ideally at the point of care, and when the protein biomarker level in blood is very low (i.e. the disease is in an early stage) is being advanced by nanosensor technology. In a recent development, scientists in Spain have developed a rapid nanochannel-based immunoassay capable of the filtering and subsequent detection of proteins in whole blood without any sample preparation. This is the first time that a simple assay to detect proteins in whole blood using nanochannels has been achieved. This is a simple device and set-up that allows nanochannels to achieve such the double functionality of filtering and detection on the same platform.
Feb 23rd, 2011
Silicon and III-V semiconductors are the respective foundations of modern electronics and photonics. Integrating these materials is essential for achieving new optoelectronic functionality and faster computer architecture. However, lattice mismatch and high III-V growth temperatures have prevented such integration thus far. Most importantly, in order to be able to take advantage of today's massive silicon infrastructure, integration must be compatible with current complementary metal-oxide-semiconductor (CMOS) infrastructure and process flows. Researchers at UC Berkeley have overcome these obstacles by developing a way to grow III-V nanolasers on silicon, demonstrating the potency of bottom-up nano-optoelectronic integration.
Feb 22nd, 2011
The recent oil spill in the Gulf of Mexico is widely acknowledged to be among the worst ocean oil spills in world history. Inevitably, the spill has once again raised serious concerns worldwide about the likely environmental impact of such catastrophic oil spills caused by oil tanker accidents at sea or mishaps during loading and unloading of oil from tankers at seaports. Numerous solutions have been proposed for dealing with the problem of oil spills. Conventional techniques are not adequate to solve the problem of massive oil spills. In recent years, nanotechnology has emerged as a potential source of novel solutions to many of the world's outstanding problems. Although the application of nanotechnology for oil spill cleanup is still in its nascent stage, there has been particularly growing interest in exploring ways of finding suitable solutions to clean up oil spills through use of nanomaterials.
Feb 21st, 2011
Previous research has shown that high performance piezoelectric ceramics PZT (lead zirconate titanate) could be printed as nanoribbons onto biocompatible and flexible substrates for applications such as harvesting energy from human motion like walking or breathing. While some motions, such as walking, only require flexibility, others, such as breathing, require that the materials be not just flexible but also stretchable. However, the PZT ribbons cannot stand stretching operation modes due to their brittle nature, which leads to cracking. The research team therefore has been looking to overcome this difficulty by fashioning the piezoelectric ribbons into wavy shapes, and integrating them with stretchable silicone rubber, such that the composite material can withstand large amounts of elastic strain.
Feb 18th, 2011