25 Jun 2016
Northwestern University: The Power of the “Gene Chip” Coming to Nanotechnology: Ability to Rapidly Test Millions/ Billions of Nanoparticles at ONE Time
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Genesis Nanotechnology, Inc. ~ “Great Things from Small Things”
Nanoscience is one of the fastest growing and most impactful fields in global scientific research. In order to support the continued development of nanoscience and nanotechnology, it is important that nanoscience education be a top priority to accelerate research excellence. In this Nano Focus, we discuss current approaches to nanoscience training and propose a learning design framework to promote the next generation of nanoscientists. Prominent among these are the abilities to communicate and to work across and between conventional disciplines. While the United States has played leading roles in initiating these developments, the global landscape of nanoscience calls for worldwide attention to this educational need. Recent developments in emerging nanoscience nations are also discussed. Photo credit: Jae Hyeon Park.
“Education has long been recognized as an important factor for growing the fields of nanoscience and nanotechnology and solidifying and expanding their roles in the global economy. In many countries, there is growing interest in developing educational programs across the full spectrum of educational levels from K-12 to postgraduate studies.
Various formal and informal educational practices are being designed and tested that promote general awareness of nanoscience and nanotechnology as well as provide advanced learning and skills development, including through group learning and peer assessment”In their article, the authors discuss innovative learning models that are being applied at the undergraduate level in order to train future leaders at the interface of engineering and management.
Middle and high school students spend time at the California NanoSystems Institute at UCLA running nanoscience experiments. High school teachers from over 100 schools and 30 school districts are trained, networked to one another, and supplied with kits for their classrooms. Graduate students, postdocs, faculty, and staff run, expand, and improve these fully subscribed outreach events on a continuous basis. (© American Chemical Society)
While thee programs are not strictly focused on nanotechnology, many graduates pursue nanotechnology-focused careers and they provide examples of important factors that should be considered in the nanotechnology field.Moreover, they represent the growing trend of holistic learning, which integrates coursework across disciplines, promotes foreign experiences, and encourages industrial internships.
Here is the set of recommendations they make:
Inspire Students To Envision What Is or Could Be Possible
Possibilities include a greater focus on nanotechnology applications in courses or hands-on laboratory experiences that tie in with class concepts. Even before reaching the classroom, students should have positive views of nanoscience and the potential it holds. Successful learning practices start with capturing the imagination of students. Communicating the remarkable features of nanoscience in a simple and clear way to the mainstream public would go a long way toward achieving this goal.
Promote Role Models Who Impact Society
From an educational perspective, the tech world is a particularly good example because successful entrepreneurs such as Steve Jobs, Elon Musk, Sheryl Sandberg, and Mark Zuckerberg have captured the public audience and inspired countless students to think beyond the classroom. In nanotechnology, similar role models can inspire students with the many opportunities available in the field.
Encourage Global Collaboration
Nanotechnology research and development is truly global. Early exposure to these trends will better inform students about career opportunities and give them ideas about how to work together in teams across disciplines and cultures. A growing number of partnerships already provide international experiences for nanoscience and nanotechnology students.
Support Early Exposure Inside and Outside of the Laboratory
For many students, nanoscience and nanotechnology are about working in a lab doing scientific research. While this activity is common, its generalization could not be farther from the truth. There are many possible ways to get involved in nanotechnology, from instructional education and hands-on training to entrepreneurship and manufacturing.Holistic approaches that integrate these different possibilities, while providing targeted career development, would greatly benefit students and the overall goals of nanotechnology education. Developing a strong workforce infrastructure for nanotechnology
Communication Across Fields
Stressing the importance of communication, the authors conclude:
“Finally, one of the great strengths of the nanoscience and nanotechnology communities is that we have taught each other how to communicate across fields, to look at and to leverage each other’s approaches, and to address the key issues of a multitude of fields.
As a field, we are increasingly viewed as problem solvers in science and technology, developing new tools, materials, methods, and opportunities. Bringing this aspect of our field to students (and scientists and engineers at all levels) will have significant impact on the world around us and our ability to make it better.”
By Michael Berger. © Nanowerk
Genesis Nanotechnology, Inc. ~ “Great Things from Small Things”
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Genesis Nanotechnology, Inc. ~ “Great Things from Small Things”
Author: Tilda Barliya PhD
Peripheral nerve lacerations are common injuries and often cause long lasting disability (1a) due to pain, paralyzed muscles and loss of adequate sensory feedback from the nerve receptors in the target organs such as skin, joints and muscles (1b).
Nerve injuries are common and typically affect young adults with the majority of injuries occur from trauma or complication of surgery. Traumatic injuries can occur due to stretch, crush, laceration (sharps or bone fragments), and ischemia, and are more frequent in wartime, i.e., blast exposure. Domestic or occupational accidents with glass, knifes of machinery may also occur.
Statistics show that peripheral nervous system (PNS) injuries were 87% from trauma and 12% due to surgery (one-third tumor related, two-thirds non– tumor related). Nerve injuries occurred 81% of the time in theupper extremities and 11% in the lower extremities, with the balance in other locations (4).
Injury to the PNS can range from severe, leading to major loss of function or intractable neuropathic pain, to mild, with some sensory and/or motor deficits affecting quality of life.
Functional recovery after nerve injury involves a complex series of steps, each of which may delay or impair the regenerative process. In cases involving any degree of nerve injury, it is useful initially to categorize these regenerative steps anatomically on a gross level. The sequence of regeneration may be divided into anatomical zones (4):
- the neuronal cell body
- the segment between the cell body and the injury site
- the injury site itself
- the distal segment between the injury site and the end organ
- the end organ itself
A delay in regeneration or unsuccessful regeneration may be attributed to pathological changes that impede normal reparative processes at one or more of these zones.
Repairing nerve defects with large gaps remains one of the most operative challenges for surgeons. Incomplete recovery from peripheral nerve injuries can produce a diversity of negative outcomes, including numbness, impairment of sensory or motor function, possibility of developing chronic pain, and devastating permanent disability.
In the past few years several techniques have been used to try and repair nerve defects and include:
- Nerve autograph
- Biological or polymeric nerve conduits (hollow nerve guidance conduits)
For example, When a direct repair of the two nerve ends is not possible, synthetic or biological nerve conduits are typically used for small nerve gaps of 1 cm or less. For extensive nerve damage over a few centimeters in length, the nerve autograft is the “gold standard” technique. The biggest challenges, however, are the limited number and length of available donor nerves, the additional surgery associated with donor site morbidity, and the few effective nerve graft alternatives.
Degeneration of the axonal segment in the distal nerve is an inevitable consequence of disconnection, yet the distal nerve support structure as well as the final target must maintain efficacy to guide and facilitate appropriate axonal regeneration. There is currently no clinical practice targeted at maintaining fidelity of the distal pathway/target, and only a small number of researchers are investigating ways to preserve the distal nerve segment, such as the use of electrical stimulation or localized drug delivery. Thus development of tissue-engineered nerve graft may be a better matched alternative (6,7).
The guidance conduit serves several important roles for nerve regeneration such as: a) directing axonal sprouting from the regenerating nerve b) protecting the regenerating nerve by restricting the infiltration of fibrous tissue c) providing a pathway for diffusion of neurotropic and neurotophic factors
Early guidance conduits were primarily made of silicone due to its stability under physiological conditions, biocompatibility, flexibility as well as ease of processing into tubular structures. Although silicone conduits have proven reasonably successful as conduits for small gap lengths in animal models (<5 mm). The non-biodegradability of silicone conduits has limited its application as a strategy for long-term repair and recovery. Tubes also eventually become encapsulated with fibrous tissue, which leads to nerve compression, requiring additional surgical intervention to remove the tube.Another limiting factor with inert guidance conduits is that they provide little or no nerve regeneration for gap lengths over 10 mm in the PNS unless exogenous growth factors are used (6,7).
In animal studies, biodegradable nerve guidance conduits have provided a feasible alternative, preventing neuroma formation and infiltration of fibrous tissue. Biodegradable conduits have been fabricated from natural or synthetic materials such as collagen, chitosan and poly-L-lactic acid.
Nanostructured Scaffolds for Neural Tissue Engineering: Fabrication and Design
At the micro- and nanoscale, cells of the CNS/PNS reside within functional microenvironments consisting of physical structures including pores, ridges, and fibers that make up the extracellular matrix (ECM) and plasma membrane cell surfaces of closely apposed neighboring cells. Cell-cell and cell-matrix interactions contribute to the formation and function of this architecture, dictating signaling and maintenance roles in the adult tissue, based on a complex synergy between biophysical (e.g. contact-mediated signaling, synapse control), and biochemical factors (e.g. nutrient support and inflammatory protection). Neural tissue engineering scaffolds are aimed toward recapitulating some of the 3D biological signaling that is known to be involved in the maintenance of the PNS and CNS and to facilitate proliferation, migration and potentially differentiation during tissue repair.
Nanotechnology and tissue engineering are based on two main approaches:
- Electrospinning (top-down) – involves the production of a polymer filament using an electrostatic force. Electrospinning is a versatile technique that enables production of polymer fibers with diameters ranging from a few microns to tens of nanometers.
- Molecular self-assembly of peptides (bottom-up) – Molecular self-assembly is mediated by weak, non-covalent bonds, such as van der Waals forces, hydrogen bonds, ionic bonds, and hydrophobic interactions. Although these bonds are relatively weak, collectively they play a major role in the conformation of biological molecules found in nature.
Pfister et al (6) very nicely summarized the various polymeric fibers been used to achieve the goal of nerve regeneration, even in humans. These material include a wide array of polymers from silica to PLGA/PEG and Diblock copolypeptides.
Many of these approaches also enlist many trophic factors that have been investigated in nerve conduits
Currently there are three general biomaterial approaches for local factor delivery:
- Incorporation of factors into a conduit filler such as a hydrogel
- Designing a drug release system from the conduit biomaterial such as microspheres
- Immobilizing factors on the scaffold that are sensed in place or liberated upon matrix degradation.
Maeda et al had a creative approach to bridge larger gaps by using the combination of nerve grafts and open conduits in an alternating “stepping stone” assembly, which may perform better than an empty conduit alone (8).
Peripheral nerve repair is a growing field with substantial progress being made in more effective repairs. Nanotechnology and biomedical engineering have made significant contributions; from surgical instrumentation to the development of tissue engineered grafting substitutes. However, to date the field of neural tissue engineering has not progressed much past the conduit bridging of small gaps and has not come close to matching the autograf. Much more studies are needed to understand the cell behaviour that can promote cell survival, neurite outgrowth, appropriate re-innervation and consequently the functional recovery post PNS/CNS injuries. This is since understanding of the cellular response to the combination of these external cues within 3D architectures is limited at this stage.
1a. Jaquet JB, Luijsterburg AJ, Kalmijn S, Kuypers PD, Hofman A, Hovius SE. Median, ulnar, and combined median-ulnar nerve injuries:functional outcome and return to productivity. J Trauma 2001 51: 687-692.http://www.ncbi.nlm.nih.gov/pubmed/11586160
1b. Lundborg G, Rosen B. Hand function after nerve repair. Acta Physiol (Oxf) 2007 189: 207-217. http://www.ncbi.nlm.nih.gov/pubmed/17250571
1. Chang WC., Kliot M and Stretavan DW. Microtechnology and Nanotechnology in Nerve Repair. Neurological Research 2008; vol 30: 1053-1062. http://vision.ucsf.edu/sretavan/sretavanpdfs/2008b-Chang%20&%20Sretavan.pdf
2. Biazar E., Khorasani MT and Zaeifi D. Nanotechnology for peripheral nerve regeneration. Int. J. Nano. Dim. 2010 1(1): 1-23. http://www.ijnd.ir/doc/2010-v1-i1/2010-V1-I1-1.pdf
3. Albert Aguayo. Nerve regeneration revisited. Nature Reviews Neuroscience 7, 601 (August 2006).
4. Burnett MG and Zager EL. Pathophysiology of Peripheral Nerve Injury: A Brief Review. Neurosurg Focus. 2004;16(5) .
5. Dag Welin. Neuroprotection and axonal regeneration after peripheral nerve injury. MEDICAL DISSERTATIONS
Welin, D., Novikova, L.N., Wiberg, M., Kellerth, J-O. and Novikov, L.N. Survival and regeneration of cutaneous and muscular afferent neurons after peripheral nerve injury in adult rats. Experimental Brain Research, 186, 315-323, 2008.
6. Pfister BJ., Gordon T., Loverde JR., Kochar AS., Mackinnon SE and Cullen Dk. Biomedical Engineering Strategies for Peripheral Nerve Repair: Surgical Applications, State of the Art, and Future Challenges. Critical Reviews™ in Biomedical Engineering 2011, 39(2):81–124.http://www.med.upenn.edu/cullenlab/user_documents/2011Pfisteretal-PNIReviewArticleCritRevBME.pdf
7. Zhou K, Nisbet D, Thouas G, Bernard C and Forsythe J. Bio-nanotechnology Approaches to Neural Tissue Engineering. Intechopen. Com. http://cdn.intechopen.com/pdfs/9811/InTech-Bio_nanotechnology_approaches_to_neural_tissue_engineering.pdf
8. Maeda T, Mackinnon SE, Best TJ, Evans PJ, Hunter DA, Midha RT. Regeneration across ’stepping-stone’ nerve grafts. Brain Res. 1993;618(2):196–202. http://www.ncbi.nlm.nih.gov/pubmed/?term=Maeda+T+and+regeneration+across+stepping+stone
13 Jun 2016
A cross-disciplinary team at Harvard University has created a system that uses solar energy to split water molecules and hydrogen-eating bacteria to produce liquid fuels. The system can convert solar energy to biomass with 10 percent efficiency, far above the one percent seen in the fastest-growing plants.
The bionic leaf is one step closer to reality.
Daniel Nocera, a professor of energy science at Harvard who pioneered the use of artificial photosynthesis, says that he and his colleague Pamela Silver have devised a system that completes the process of making liquid fuel from sunlight, carbon dioxide, and water. And they’ve done it at an efficiency of 10 percent, using pure carbon dioxide—in other words, one-tenth of the energy in sunlight is captured and turned into fuel.
That is much higher than natural photosynthesis, which converts about 1 percent of solar energy into the carbohydrates used by plants, and it could be a milestone in the shift away from fossil fuels. The new system is described in a new paper in Science.
“Bill Gates has said that to solve our energy problems, someday we need to do what photosynthesis does, and that someday we might be able to do it even more efficiently than plants,” says Nocera. “That someday has arrived.”
In nature, plants use sunlight to make carbohydrates from carbon dioxide and water. Artificial photosynthesis seeks to use the same inputs—solar energy, water, and carbon dioxide—to produce energy-dense liquid fuels. Nocera and Silver’s system uses a pair of catalysts to split water into oxygen and hydrogen, and feeds the hydrogen to bacteria along with carbon dioxide.
The bacteria, a microörganism that has been bioengineered to specific characteristics, converts the carbon dioxide and hydrogen into liquid fuels.
Several companies, including Joule Unlimited and LanzaTech, are working to produce biofuels from carbon dioxide and hydrogen, but they use bacteria that consume carbon monoxide or carbon dioxide, rather than hydrogen. Nocera’s system, he says, can operate at lower temperatures, higher efficiency, and lower costs.
Nocera’s latest work “is really quite amazing,” says Peidong Yang of the University of California, Berkeley. Yang has developed a similar system with much lower efficiency. “The high performance of this system is unparalleled” in any other artificial photosynthesis system reported to date, he says.
The new system can use pure carbon dioxide in gas form, or carbon dioxide captured from the air—which means it could be carbon-neutral, introducing no additional greenhouse gases into the atmosphere. “The 10 percent number, that’s using pure CO2,” says Nocera. Allowing the bacteria themselves to capture carbon dioxide from the air, he adds, results in an efficiency of 3 to 4 percent—still significantly higher than natural photosynthesis.
“That’s the power of biology: these bioörganisms have natural CO2 concentration mechanisms.”
Nocera’s research is distinct from the work being carried out by the Joint Center for Artificial Photosynthesis, a U.S. Department of Energy-funded program that seeks to use inorganic catalysts, rather than bacteria, to convert hydrogen and carbon dioxide to liquid fuel.
According to Dick Co, who heads the Solar Fuels Institute at Northwestern University, the innovation of the new system lies not only in its superior performance but also in its fusing of two usually separate fields: inorganic chemistry (to split water) and biology (to convert hydrogen and carbon dioxide into fuel). “What’s really exciting is the hybrid approach” to artificial photosynthesis, says Co. “It’s exciting to see chemists pairing with biologists to advance the field.”
Commercializing the technology will likely take years. In any case, the prospect of turning sunlight into liquid fuel suddenly looks a lot closer.
13 Jun 2016
Nanotube Surface Technology
Nanotubes are not an additive coating. They are formed into the existing metal oxide tissue-contacting surface of implants. Titanium, tantalum, and zirconium metals and alloy implants are directly treated with an anodization process to form the nanotubes. Implants made from other materials such as PEEK, medical polymers, ceramics and CoCrMo are indirectly treated by first applying a thin layer of titanium that is then processed by a similar patented anodization technique to form nanotubes on its surface.
Any implant surface that requires stable fixation against bone such as a hip, knee, ankle, shoulder, hand, or spinal implant can be enhanced by nanotubes.
How does it work?
- It mimics the stem cells around the implant into thinking that the surface of the implant is actually another cell.
- The super-absorbent, ultra-hydrophilic surface enhances tissue cell attachment.
- The cell then spreads and branches out on the implant surface.
- The stem cell differentiates to match the cells that are around the nanotube surface.
- If around bone cells, Osteoblasts form and the mineralization process begins.
- If near cartilage, chondrocyte cells form starting cartilage regeneration
“In Vivo studies have shown that titanium implants that have nanotubes on them have a nine times greater osseointegration bond strength as compared to implants that don’t. We also see faster cell differentiation—the bonding happens weeks faster than it would without nanotubes. We’re interested in allowing patients to walk on or fully use their implants faster. We’re trying to speed that up not by days, but by weeks and perhaps months”
The most difficult to treat and deadly of cancers may have met their match. Nanotechnology, at the forefront of cancer research, now has a new application, Medical News Today reports.
Mauro Ferrari, president and CEO of the Houston Methodist Research Institute in Texas, has found a way to inject metastatic tumors with nanoparticles, releasing cancer-fighting drugs directly into the tumors themselves.
Existing cancer drugs are limited in the fight against tumors in areas like the lungs and liver because of the body’s protective biological barriers. Basically, the cancer fighting drugs fail to reach their intended targets and wind up damaging healthy tissues.
“This may sound like science fiction, like we’ve penetrated and destroyed the Death Star, but what we discovered is transformational,” Ferrari tells Medical News Today. “I would never want to over-promise to the thousands of cancer patients looking for a cure, but the data is astounding.
“We’re talking about changing the landscape of curing metastatic disease, so it’s no longer a death sentence.”
“The Rest of the Story”
A few decades ago, the idea of developing any type of solution in the nanoscale was nothing more than a dream.
The word “nanotechnology” was only seen in print for the first time as recently as 1986.
Manipulating, creating and utilizing objects that are 100,000 times smaller than the width of a hair is science fiction turned science fact.
Today, nano-sized particles help golf balls fly straighter, make the surfaces of bowling balls more durable and give exterior varnishes a longer life.
Industry and manufacturing have taken nanoparticles to their bosom, but their abilities are also being tested for possible uses in the medical sphere; for instance, bandages infused with silver nanoparticles have been designed to help wounds heal faster.
Among the list of potential medical uses for nanotechnology are targeted drug delivery systems in the fight against diseases, including cancer.
Current cancer drug delivery
Metastases of cancers in the lung and liver are the primary causes of cancer deaths. In many cases, existing cancer drugs are of limited powerbecause of the body’s protective biological barriers. The chemicals fail to reach their intended targets in high enough concentrations and are distributed into healthy tissues, causing serious side effects.
Mauro Ferrari, president and CEO of the Houston Methodist Research Institute in Texas, has been working with nanomedicine for 20 years, and his latest research provides some of the most impressive results to date.
Ferrari and his team created a mechanism by which nanoparticles could move through these biological defenses and, once inside the tumor, release the toxic chemicals directly into the heart of the problem.
Injectable nanoparticle generator
The team used an injectable nanoparticle generator (iNPG), composed of the active drug – doxorubicin – packaged as thin strands of polymer within a nanoporous silicon material.
Once the iNPG enters the tumor, the silicon outer coating naturally degrades, releasing the polymer strands. The strands curl up into nano-scale balls and enter the cancer cells themselves. As the balls move freely around the cell and approach the nucleus, the pH becomes more acidic. This drop in pH triggers the strands to release the doxorubicin, which then kills the cell.
The iNPGs were trialed on mice with triple negative breast cancer that had metastasized into the tissues of the lungs. Triple negative cancers account for roughly 1 in 10 breast cancers. They are particularly difficult to treat and do not respond to hormonal therapy.
‘What we discovered is transformational’
Although the prognosis for triple negative cancer is poor, Ferrari and his team found that 50% of the mice treated by the iNPGs showed no traces of metastatic disease after an 8-month period, which is considered the equivalent of 24 human years.
“This may sound like science fiction, like we’ve penetrated and destroyed the Death Star, but what we discovered is transformational. We invented a method that actually makes the nanoparticles inside the cancer and releases the drug particles at the site of the cellular nucleus.”
The investigators are incredibly pleased with these results and hope they will shepherd in a new dawn of medical intervention. Any headway into the treatment of such an intractable disease is entirely welcome.
The authors say that “with this injectable nanoparticle generator, we were able to do what standard chemotherapy drugs, vaccines, radiation and other nanoparticles have all failed to do.” The Houston Methodist Research Institute are hoping to fast-track the research and secure FDA (US Food and Drug Administration) approval as soon as possible. They plan to trial the drugs in humans in 2017.
Although keen to keep the findings in perspective and not raise hopes unnecessarily, Ferrari has a difficult time keeping his positivity under wraps:
“I would never want to over-promise to the thousands of cancer patients looking for a cure, but the data is astounding. We’re talking about changing the landscape of curing metastatic disease, so it’s no longer a death sentence.”
Ferrari’s excitement is both palpable and understandable. Even if future research using human participants returns with survival rates that are only a fraction of those found in the present study, the results will be deemed a rousing success.
Medical News Today recently covered news of another “groundbreaking” cancer discovery that holds promise for personalizing cancer therapy.
13 Jun 2016
Scientists at UC San Diego, MIT and Harvard University have engineered “topological plexcitons,” energy-carrying particles that could help make possible the design of new kinds of solar cells and miniaturized optical circuitry.
The researchers report their advance in an article published in the current issue of Nature Communications.
Within the Lilliputian world of solid state physics, light and matter interact in strange ways, exchanging energy back and forth between them.
“When light and matter interact, they exchange energy,” explained Joel Yuen-Zhou, an assistant professor of chemistry and biochemistry at UC San Diego and the first author of the paper. “Energy can flow back and forth between light in a metal (so called plasmon) and light in a molecule (so called exciton). When this exchange is much faster than their respective decay rates, their individual identities are lost, and it is more accurate to think about them as hybrid particles; excitons and plasmons marry to form plexcitons.”
Materials scientists have been looking for ways to enhance a process known as exciton energy transfer, or EET, to create better solar cells as well as miniaturized photonic circuits which are dozens of times smaller than their silicon counterparts.
“Understanding the fundamental mechanisms of EET enhancement would alter the way we think about designing solar cells or the ways in which energy can be transported in nanoscale materials,” said Yuen-Zhou.
The drawback with EET, however, is that this form of energy transfer is extremely short-ranged, on the scale of only 10 nanometers, and quickly dissipates as the excitons interact with different molecules.
One solution to avoid those shortcomings is to hybridize excitons in a molecular crystal with the collective excitations within metals to produce plexcitons, which travel for 20,000 nanometers, a length which is on the order of the width of human hair.
Plexcitons are expected to become an integral part of the next generation of nanophotonic circuitry, light-harvesting solar energy architectures and chemical catalysis devices. But the main problem with plexcitons, said Yuen-Zhou, is that their movement along all directions, which makes it hard to properly harness in a material or device.
He and a team of physicists and engineers at MIT and Harvard found a solution to that problem by engineering particles called “topological plexcitons,” based on the concepts in which solid state physicists have been able to develop materials called “topological insulators.”
“Topological insulators are materials that are perfect electrical insulators in the bulk but at their edges behave as perfect one-dimensional metallic cables,” Yuen-Zhou said. “The exciting feature of topological insulators is that even when the material is imperfect and has impurities, there is a large threshold of operation where electrons that start travelling along one direction cannot bounce back, making electron transport robust. In other words, one may think about the electrons being blind to impurities.”
Plexcitons, as opposed to electrons, do not have an electrical charge. Yet, as Yuen-Zhou and his colleagues discovered, they still inherit these robust directional properties. Adding this “topological” feature to plexcitons gives rise to directionality of EET, a feature researchers had not previously conceived. This should eventually enable engineers to create plexcitonic switches to distribute energy selectively across different components of a new kind of solar cell or light-harvesting device.
More information: Nature Communications, DOI: 10.1038/NCOMMS11783
Genesis Nanotechnology, Inc. ~ “Great Things from Small Things”
13 Jun 2016
Australian researchers at the University of Adelaide have developed a method for embedding light-emitting nanoparticles into glass without losing any of their unique properties – a major step towards ‘smart glass’ applications such as 3D display screens or remote radiation sensors.
This new “hybrid glass” successfully combines the properties of these special luminescent (or light-emitting) nanoparticles with the well-known aspects of glass, such as transparency and the ability to be processed into various shapes including very fine optical fibres.
The research, in collaboration with Macquarie University and University of Melbourne, has been published online in the journal Advanced Optical Materials.
“These novel luminescent nanoparticles, called upconversion nanoparticles, have become promising candidates for a whole variety of ultra-high tech applications such as biological sensing, biomedical imaging and 3D volumetric displays,” says lead author Dr Tim Zhao, from the University of Adelaide’s School of Physical Sciences and Institute for Photonics and Advanced Sensing (IPAS).
“Integrating these nanoparticles into glass, which is usually inert, opens up exciting possibilities for new hybrid materials and devices that can take advantage of the properties of nanoparticles in ways we haven’t been able to do before. For example, neuroscientists currently use dye injected into the brain and lasers to be able to guide a glass pipette to the site they are interested in. If fluorescent nanoparticles were embedded in the glass pipettes, the unique luminescence of the hybrid glass could act like a torch to guide the pipette directly to the individual neurons of interest.”
Although this method was developed with upconversion nanoparticles, the researchers believe their new ‘direct-doping’ approach can be generalised to other nanoparticles with interesting photonic, electronic and magnetic properties. There will be many applications – depending on the properties of the nanoparticle.
“If we infuse glass with a nanoparticle that is sensitive to radiation and then draw that hybrid glass into a fibre, we could have a remote sensor suitable for nuclear facilities,” says Dr Zhao.
To date, the method used to integrate upconversion nanoparticles into glass has relied on the in-situ growth of the nanoparticles within the glass.
“We’ve seen remarkable progress in this area but the control over the nanoparticles and the glass compositions has been limited, restricting the development of many proposed applications,” says project leader Professor Heike Ebendorff-Heideprem, Deputy Director of IPAS.
“With our new direct doping method, which involves synthesizing the nanoparticles and glass separately and then combining them using the right conditions, we’ve been able to keep the nanoparticles intact and well dispersed throughout the glass. The nanoparticles remain functional and the glass transparency is still very close to its original quality. We are heading towards a whole new world of hybrid glass and devices for light-based technologies.”
Explore further: Ancient Roman glass inspires modern science
More information: Jiangbo Zhao et al. Upconversion Nanocrystal-Doped Glass: A New Paradigm for Photonic Materials, Advanced Optical Materials(2016). DOI: 10.1002/adom.201600296