Harvesting unexploited energy in the living environment is increasingly becoming an intense research area as the global push to replace fossil fuels with clean and renewable energy sources heats up. There is an almost infinite number of mechanical energy sources all around us - basically, anything that moves can be harvested for energy. This ranges from the very large, like wave power in the oceans, to the very small like rain drops or biomechanical energy from heart beat, breathing, and blood flow. In an intriguing demonstration, researchers at Georgia Tech have now demonstrated that the technology offered by nanogenerators can also be used for large-scale energy harvesting.
DNA is a powerful biomaterial for creating rationally designed and functionally enhanced nanostructures. Emerging DNA nanotechnology employs DNA as a programmable building material for self-assembled, nanoscale structures. Researchers have also shown that DNA nanotechnology can be integrated with traditional silicon processing. DNA nanoarchitectures positioned at substrate interfaces can offer unique advantages leading to improved surface properties relevant to biosensing (for instance, graphene and DNA can combine to create a stable and accurate biosensor), nanotechnology, materials science, and cell biology.
A key benefit of nanoimprint lithography is its sheer simplicity. There is no need for complex optics or high-energy radiation sources with a nanoimprint tool. Especially the nanopatterning of high refractive index optical films promises the development of novel photonic nanodevices such as planar waveguide circuits, nano-lasers, solar cells and antireflective coatings. Researchers have now developed a robust route for high-throughput, high-performance nanophotonics based direct imprint of high refractive index, low visible wavelength absorption materials.
Currently, optically absorbing nanoparticles are breaking into clinical medicine because of their ability to aid in the identification of disease with several medical imaging modalities. These nanoparticles are also used in therapeutics by triggering drug release or enhancing ablation of diseased tissues, while minimizing damage to healthy tissues. The efficiency and effectiveness of the medical imaging and therapeutics using nanoparticles depends on the ability to selectively target them to the specific tissues. A novel method only uses properties of the nanoparticles and therefore are independent of the amount of nanoparticles that reaches the target location.
Researchers are applying various strategies to designing nanoscale propulsion systems by either using or copying biological systems such as the flagellar motors of bacteria or by employing various chemical reactions. Different practical micromotor applications, ranging from drug delivery, to target isolation and environmental remediation, have thus been reported over the past 2-3 years. Yet, there are no reports on a nanomachine-based toxicity assay approach, analogous to the use of live aquatic organisms for testing the quality of our water resources.
Spores are reproductive structures that have developed in nature to preserve genetic information and protect cellular components in harsh conditions and against external stresses such as nutrient deprivation, high temperatures, or radiation. Spores form part of the life cycles of many bacteria and plants. The cellular components of a spore are protected against the environment by a very robust hierarchical shell structure that allows it to survive for many years under hostile conditions found naturally that can easily and quickly kill normal cells. By developing the concept of artificial spores, researchers have been developing strategies to coat single cells with a hard, protective layer of a hard thin shells.
Within graphene research, transmission electron microscopy (TEM) has proven to be an extremely useful and versatile characterization tool. However, the electron beam can interact with the sample leading to its modification during the process. This may be an undesirable effect and measures to avoid this do exist. In other cases, however, electron beam-sample interactions can be useful for nanoengineering or nanomanufacturing. It is therefore crucially important to understand how a material responds to the electron beam and the environment inside a TEM. In new work, researchers have now demonstrated that damage-free sculpting of graphene with condensed electron beams is feasible.
In order to fabricate stimuli-responsive materials, researchers have shown a lot of interest in asymmetric materials such as modulated gels which consist of a controlled layer that is responsive to an environmental stimuli and a nonresponsive substrate layer. And while much effort has gone into creating free-standing films through layer-by-layer (LbL) assembly, relatively little attention has been paid to the asymmetric properties or functionalization of the two surfaces of such free-standing layer-by-layer films. In new work, researchers have now reported the fabrication of asymmetric free-standing layer-by-layer film with asymmetric wettability - one surface is superhydrophobic and the other one is hydrophilic. The superhydrophobic side is water-repellent while the hydrophilic side can absorb/desorb water easily.