21 Nov 2016
Quantum computing is heralded as the next revolution in terms of global computing. Google, Intel and IBM are just some of the big names investing millions currently in the field of quantum computing which will enable faster, more efficient computing required to power the requirements of our future computing needs.
|Now a researcher and his team at Tyndall National Institute in Cork have made a ‘quantum leap’ by developing a technical step that could enable the use of quantum computers sooner than expected.|
|Conventional digital computing uses ‘on-off’ switches, but quantum computing looks to harness quantum state of matters – such as entangled photons of light or multiple states of atoms – to encode information. In theory, this can lead to much faster and more powerful computer processing, but the technology to underpin quantum computing is currently difficult to develop at scale.|
|Researchers at Tyndall have taken a step forward by making quantum dot light-emitting diodes (LEDs) that can produce entangled photons (whose actions are linked), theoretically enabling their use to encode information in quantum computing.|
|This is not the first time that LEDs have been made that can produce entangled photons, but the methods and materials described in the new paper (Nature Photonics, “Selective carrier injection into patterned arrays of pyramidal quantum dots for entangled photon light-emitting diodes”) have important implications for the future of quantum technologies, explains researcher Dr Emanuele Pelucchi, Head of Epitaxy and Physics of Nanostructures and a member of the Science Foundation Ireland-funded Irish Photonic Integration Centre (IPIC) at Tyndall National Institute in Cork.|
|Dr Emanuele Pelucchi.|
|“The new development here is that we have engineered a scalable array of electrically driven quantum dots using easily-sourced materials and conventional semiconductor fabrication technologies, and our method allows you to direct the position of these sources of entangled photons,” he says.|
|“Being able to control the positions of the quantum dots and to build them at scale are key factors to underpin more widespread use of quantum computing technologies as they develop.”|
|The Tyndall technology uses nanotechnology to electrify arrays of the pyramid-shaped quantum dots so they produce entangled photons. “We exploit intrinsic nanoscale properties of the whole “pyramidal” structure, in particular, an engineered self-assembled vertical quantum wire, which selectively injects current into the vicinity of a quantum dot,” explains Dr Pelucchi.|
|“The reported results are an important step towards the realization of integrated quantum photonic circuits designed for quantum information processing tasks, where thousands or more sources would function in unison.”|
|“It is exciting to see how research at Tyndall continues to break new ground, particularly in relation to this development in quantum computing. The significant breakthrough by Dr Pelucchi advances our understanding of how to harness the opportunity and power of quantum computing and undoubtedly accelerates progress in this field internationally. Photonics innovations by the IPIC team at Tyndall are being commercialized across a number sectors and as a result, we are directly driving global innovation through our investment, talent and research in this area,” said Dr Kieran Drain, CEO at Tyndall National Institute.|
|Source: Tyndall National Institute|
07 Oct 2016
** Special to the Washington Post
The batteries that power our high-tech lifestyle are built using materials extracted in dirty, often life-threatening conditions.
If you have a cell phone, laptop, a hybrid car, or an electric vehicle, you may want to sit down. This may hurt.
You have probably heard of blood diamonds and conflict minerals. Maybe you’ve even read up a bit on how big consumer tech companies are trying (and, in some cases, being forced by governments) to sort out where the materials that go into their gadgets come from. But stories about “supply chains,” “globalization,” and “poor working conditions” can seem a world away, or just plain academic.
In a sweeping, heartbreaking series, the Washington Post is making sure it hits home.
Take the example of Yu Yuan, a farmer who lives near a graphite factory in northeastern China. In a video, he swipes at shimmering grime accumulated in his window sill and points at a barren cornfield.
The crops turn black with graphite dust he says, and don’t grow properly. He and his wife worry about the air they’re breathing and their water is undrinkable, polluted by chemicals dumped from the graphite plant. “There is nothing here once the factory is done damaging this place,” he says.
Workers in Lubumbashi, Democratic Republic of the Congo, tend to an oven that processes slag from the region’s cobalt and copper-rich ores.
Over two pieces so far, the Post has traced the path of first cobalt and then graphite as they make their way from mines to factories and ultimately into our hands as the cathodes and anodes, respectively, for lithium-ion batteries.
Each story is a remarkable blend of globe-spanning investigative journalism, business reporting, and an appeal to us to confront the consequences of owning the devices that power our high-tech lifestyles.
While graphite is mined and processed mostly in China, a huge amount of cobalt comes from mines in the Democratic Republic of the Congo, where “artisanal” miners sometimes dig through the floor of their own houses in search of ore. Mines collapse frequently. Injuries and death are commonplace.
Once extracted, the materials end up in Asia, where companies you’ve probably never heard of turn them into battery parts. The largest battery makers in the world, including Samsung SDI, LG Chem, and Panasonic, then purchase the components and turn them into batteries that go into phones, computers, and cars. (article continued below)
A “New Way” to Power Our World?
Read (Watch the YouTube Video Below) About a New Energy Storage Company ~ Making Energy Dense, Flexible Form, Rapid Charge/ Re-Charge Super Capacitors and Batteries for Medical Devices, Drone Batteries, Power Banks, Motorcycle and EV Batteries, developed from a Rice University Technology using ‘Nanoporous Nickle’ and ‘Si Nano Wires.
(article continued) Lithium batteries are prized for being light and having a high energy density compared to other battery chemistries. The modern smartphone would be difficult to imagine without a lithium battery as its power supply. They help power hybrid cars, and the small but fast-growing fleet of all-electric vehicles wouldn’t exist without them.
Interest in electric cars, in particular, is fueled by claims that the vehicles are clean and good for the environment. That may be true in the countries where they are mostly sold. But when we consider the bigger picture, the reality is something else altogether.
Read More: MIT Review – August 2016
Startups with novel chemistries tend to falter before they reach full production.
Earlier this year, Ellen Williams, the director of ARPA-E, the U.S. Department of Energy’s advanced research program for alternative energy, made headlines when she told the Guardiannewspaper that “We have reached some holy grails in batteries.”
Despite very promising results from the 75-odd energy-storage research projects that ARPA-E funds, however, the grail of compact, low-cost energy storage remains elusive.
A number of startups are closer to producing devices that are economical, safe, compact, and energy-dense enough to store energy at a cost of less than $100 a kilowatt-hour. Energy storage at that price would have a galvanic effect, overcoming the problem of powering a 24/7 grid with renewable energy that’s available only when the wind blows or the sun shines, and making electric vehicles lighter and less expensive.
But those batteries are not being commercialized at anywhere near the pace needed to hasten the shift from fossil fuels to renewables. Even Tesla CEO Elon Musk, hardly one to underplay the promise of new technology, has been forced to admit that, for now, the electric-car maker is engaged in a gradual slog of enhancements to its existing lithium-ion batteries, not a big leap forward.
In fact, many researchers believe energy storage will have to take an entirely new chemistry and new physical form, beyond the lithium-ion batteries that over the last decade have shoved aside competing technologies in consumer electronics, electric vehicles, and grid-scale storage systems. In May the DOE held a symposium entitled “Beyond Lithium-Ion.” The fact that it was the ninth annual edition of the event underscored the technological challenges of making that step.
Qichao Hu, the founder of SolidEnergy Systems, has developed a lithium-metal battery (which has a metallic anode, rather than the graphite material used for the anode in traditional lithium-ion batteries) that offers dramatically improved energy density over today’s devices (see“Better Lithium Batteries to Get a Test Flight”). The decade-long process of developing the new system highlighted one of the main hurdles in battery advancement: “In terms of moving from an idea to a product,” says Hu, “it’s hard for batteries, because when you improve one aspect, you compromise other aspects.”
Added to this is the fact that energy storage research has a multiplicity problem: there are so many technologies, from foam batteries to flow batteries to exotic chemistries, that no one clear winner is attracting most of the funding and research activity.
According to a recent analysis of more than $4 billion in investments in energy storage by Lux Research, startups developing “next-generation” batteries—i.e., beyond lithium-ion—averaged just $40 million in funding over eight years. Tesla’s investment in its Gigafactory, which will produce lithium-ion batteries, will total around $5 billion. That huge investment gap is hard to overcome.
“It will cost you $500 million to set up a small manufacturing line and do all the minutiae of research you need to do to make the product,” says Gerd Ceder, a professor of materials science at the University of California, Berkeley, who heads a research group investigating novel battery chemistries. Automakers, he points out, may test new battery systems for years before making a purchase decision. It’s hard to invest $500 million in manufacturing when your company has $5 million in funding a year.
Even if new battery makers manage to bring novel technologies to market, they face a dangerous period of ramping up production and finding buyers. Both Leyden Energy and A123 Systems failed after developing promising new systems, as their cash needs climbed and demand failed to meet expectations. Two other startups, Seeo and Sakti3, were acquired before they reached mass production and significant revenues, for prices below what their early-stage investors probably expected.
Meanwhile, the Big Three battery producers, Samsung, LG, and Panasonic, are less interested in new chemistries and radical departures in battery technology than they are in gradual improvements to their existing products. And innovative battery startups face one major problem they don’t like to mention: lithium-ion batteries, first developed in the late 1970s, keep getting better.
Read more: Why We Still Don’t Have Better Batteries The Washington Post
Genesis Nanotechnology, Inc.
Follow and ‘Like’ Us on Facebook: https://www.facebook.com/GenesisNanoTech/
Follow Us On Twitter: https://twitter.com/GenesisNanoTech
“Join the Conversation” on Our LinkedIn ‘Nano Network’ Group:https://www.linkedin.com/groups/3935461
Connect To Our Website: http://genesisnanotech.com/
Watch Our YouTube Video: https://youtu.be/Y1618kgUSXI
Follow Our ‘Top Ten’ Blog: “Great Things from Small Things”: https://genesisnanotech.wordpress.com/
Contact with Your Comments – We Love Hearing from You!
Credit: American Chemical Society
Batteries in smart phones and other portable electronics often die at inopportune times. Carrying a spare battery is one solution. As an alternative, researchers have tried to create fibers to incorporate in clothing that would power these devices. However, many of these fibers can’t withstand clothing manufacturing, especially weaving and cutting.
Now, in the journal ACS Nano, scientists report the first fibers suitable for weaving into tailorable textiles that can capture and release solar energy.
To collect solar power, Wenjie Mai, Xing Fan and colleagues created two different types of fibers. One contained titanium or a manganese-coated polymer along with zinc oxide, a dye and an electrolyte. These fibers were then interlaced with copper-coated polymer wires to create the solar cell section of the textile. To store power, the researchers developed a second type of fiber. This one was made of titanium, titanium nitride, a thin carbon shell to prevent oxidation and an electrolyte. These fibers were woven with cotton yarn.
When combined, the new materials formed a flexible textile that the team could cut and tailor into a “smart garment” that was fully charged by sunlight. The researchers say the clothing could potentially power small electronics including tablets and phones.(Article Continues Below – After Tenka Energy Story)
Read About (Watch the YouTube Video)
Tenka Energy, LLC is developing and commercializing the Next Generation of Super-Capacitors andBatteries, providing the High-Energy-Density,in Flexible-Thin-Form with Rapid Charge/ Recharge Cycles with Extended Life that is required and in high demand from a“power starved world”. The opportunity is based on a Nanoporous-Nickel Flexible Thin-form technology that is easily scaled, from Rice University. Applications: Powered Smart Cards, Wearable Electronics, Drone Batteries, Medical Devices, Motorcycle and EV Batteries – just to name a few!
(Article Continued) Explore further: New fabric uses sun and wind to power devices
More information: Zhisheng Chai et al. Tailorable and Wearable Textile Devices for Solar Energy Harvesting and Simultaneous Storage, ACS Nano(2016). DOI: 10.1021/acsnano.6b05293
The pursuit of harmonic combination of technology and fashion intrinsically points to the development of smart garments. Herein, we present an all-solid tailorable energy textile possessing integrated function of simultaneous solar energy harvesting and storage, and we call it tailorable textile device. Our technique makes it possible to tailor the multifunctional textile into any designed shape without impairing its performance and produce stylish smart energy garments for wearable self-powering system with enhanced user experience and more room for fashion design.
The “threads” (fiber electrodes) featuring tailorability and knittability can be large-scale fabricated and then woven into energy textiles. The fiber supercapacitor with merits of tailorability, ultrafast charging capability, and ultrahigh bending-resistance is used as the energy storage module, while an all-solid dye-sensitized solar cell textile is used as the solar energy harvesting module. Our textile sample can be fully charged to 1.2 V in 17 s by self-harvesting solar energy and fully discharged in 78 s at a discharge current density of 0.1 mA.
Genesis Nanotechnology, Inc. ~ “Great Things from Small Things”
07 Oct 2016
Equipment at a brewery. Credit: FTGallo / Wikipedia.
University of Colorado Boulder engineers have developed an innovative bio-manufacturing process that uses a biological organism cultivated in brewery wastewater to create the carbon-based materials needed to make energy storage cells.
This unique pairing of breweries and batteries could set up a win-win opportunity by reducing expensive wastewater treatment costs for beer makers while providing manufacturers with a more cost-effective means of creating renewable, naturally-derived fuel cell technologies.
“Breweries use about seven barrels of water for every barrel of beer produced,” said Tyler Huggins, a graduate student in CU Boulder’s Department of Civil, Environmental and Architectural Engineering and lead author of the new study. “And they can’t just dump it into the sewer because it requires extra filtration.”
The process of converting biological materials, or biomass, such as timber into carbon-based battery electrodes is currently used in some energy industry sectors. But, naturally-occurring biomass is inherently limited by its short supply, impact during extraction and intrinsic chemical makeup, rendering it expensive and difficult to optimize.
However, the CU Boulder researchers utilize the unsurpassed efficiency of biological systems to produce sophisticated structures and unique chemistries by cultivating a fast-growing fungus, Neurospora crassa, in the sugar-rich wastewater produced by a similarly fast-growing Colorado industry: breweries.
“The wastewater is ideal for our fungus to flourish in, so we are happy to take it,” said Huggins.
By cultivating their feedstock in wastewater, the researchers were able to better dictate the fungus’s chemical and physical processes from the start. They thereby created one of the most efficient naturally-derived lithium-ion battery electrodes known to date while cleaning the wastewater in the process.
The findings were published recently in the American Chemical Society journal Applied Materials & Interfaces.
If the process were applied on a large scale, breweries could potentially reduce their municipal wastewater costs significantly while manufacturers would gain access to a cost-effective incubating medium for advanced battery technology components.
“The novelty of our process is changing the manufacturing process from top-down to bottom-up,” said Zhiyong Jason Ren, an associate professor in CU Boulder’s Department of Civil, Environmental and Architectural Engineering and a co-author of the new study. “We’re biodesigning the materials right from the start.”
Huggins and study co-author Justin Whiteley, also of CU Boulder, have filed a patent on the process and created Emergy, a Boulder-based company aimed at commercializing the technology.
“We see large potential for scaling because there’s nothing required in this process that isn’t already available,” said Huggins.
The researchers have partnered with Avery Brewing in Boulder in order to explore a larger pilot program for the technology. Huggins and Whiteley recently competed in the finals of a U.S. Department of Energy-sponsored startup incubator competition at the Argonne National Laboratory in Chicago, Illinois.
“This research speaks to the spirit of entrepreneurship at CU Boulder,” said Ren, who plans to continue experimenting with the mechanisms and properties of the fungus growth within the wastewater. “It’s great to see students succeeding and creating what has the potential to be a transformative technology. Energy storage represents a big opportunity for the state of Colorado and beyond.”
Explore further: Researchers use wastewater treatment to capture CO2, produce energy
More information: Tyler M. Huggins et al. Controlled Growth of Nanostructured Biotemplates with Cobalt and Nitrogen Codoping as a Binderless Lithium-Ion Battery Anode, ACS Applied Materials & Interfaces (2016). DOI: 10.1021/acsami.6b09300
Read Today’s Top Stories in Nanotechnology and the ‘Business’ of Nanotechnology.
Stories about the Discoveries and Technologies that will reshape our world and drive New Economic Engines for the Future.
and much more …
Genesis Nanotechnology, Inc. ~ “Great Things from Small Things”
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
Plus More …. Click on the Link Below To Read This Week’s Publication
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”
Read Genesis Nanotech Online: Latest Nano-News and Updates
Articles and Updates Like:
… Plus many more Articles in Technology; Business and Science
Follow the Link Here: Genesis NanoTech Online:
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.