Regenerative medicine crossed another milestone this week when scientists at the University of Lund in Sweden demonstrated the direct conversion of skin tissue cells into nerve cells. So far, the standard technique in this field has been to convert adult cells (usually from the skin) into stem cells, and then converting stem cells into tissues or organs that have to be transplanted. This method has several risks and has not worked well in humans so far, although a few recent breakthroughs seem promising. The new method skirts the stem-cell route, and so avoids most of the risks associated with it.Regenerative medicine is in some ways the Holy Grail of modern medicine. Damaged organs such as kidney, liver or the retina can seldom be repaired through drugs. The only way out is to transplant a new organ. This works for some time, but brings with it other risks such as rejection. The average life expectancy of a patient with a transplanted kidney, for example, is 10-15 years. Regene-rative medicine can one day provide these people with their own organs, but so far it has not worked to the extent required for field use.Regenerative medicine is useful not just in transplanting organs. Bone marrow transplants are being used to treat leukaemia patients. Many neural diseases can in theory be treated with regenerated cells. For example, Parkinson's disease, caused by degeneration of brain cells that produce a chemical called dopamine (an important neurotransmitter involved in many brain functions) can, in theory, be treated by transplanted brain cells. However, this method has not worked in practice so far.The use of stem cells in regenerative medicine has been dogged by several controversies. The use of embryonic stem cells has been criticised as unethical and has been banned at various times in several countries. Scientists have learned to convert adult cells — particularly of the skin — into a type of stem cell called pluripotent cells (which are capable of differentiating into most organs in the body), but the use of pluripotent stem cells in therapy is dangerous because they sometimes lead to tumours. The current method in Lund avoids this step, and converts cells of one type directly into cells of another type.The Lund scientists have achieved this by reprogramming the skin cell, of a type called fibroblasts. Cells differentiate into different types because different kinds of genes become active in different kinds of tissues. You can use this process to change cells of one type into another. For example, if you shut down the liver genes in the liver cells and activate the retina genes, the liver cells will be converted into retinal cells. Lund scientists, led by Malin Parmar at the department of developmental neurology, found that this technique was much easier than people thought.Parmar and her team activated three nerve cell genes in the fibroblasts, and another two genes involved in dopamine synthesis. This led to the conversion of the fibroblasts into dopamine-producing nerve cells, thereby demonstrating a possible therapy method for Parkinson's disease. This was a major breakthrough because it opened a new avenue of research with immense potential. For scientists to actually use it in a clinical trial, they need to see how the new neurons grow in the brain. They need to optimise their methods with the right kind of starting cell, see how well the new neurons grow in the brain, whether they survive in the long term, and also how well they produce dopamine. Of course, they would also need to see whether the patients get better with the treatment. (This story was published in Businessworld Issue Dated 27-06-2011)
Read More
Hardly a week passes these days without some sort of announcement from Google. Last week it was in the realm of mobile payments, and Google took one more step in its attempt to be the dominant force in tomorrow's world. It announced its Mobile Wallet, a payment service that it is developing in the US with service provider Sprint. In simple terms, it lets you make a payment at a participating merchant store using your mobile phone. Others methods of doing this exist already, but Google has a completely different way that would provide an important alternative to operator-controlled methods widely in use in many countries.Here is how it works. Your phone stores all your credit card information. When you check out at a participating store, you can make a payment by simply tapping your phone once on a device at the counter. Google had teamed up with Citibank, MasterCard, Sprint and First Data to test and develop the technology. It hopes to roll out the service later this summer in the US, and expand to other countries — including India — in the near future. Currently, Citibank is the sole participating bank and Sprint the only participating telecom operator. But it has an impressive list of participating merchants: Subway, Bloomingdales, RadioShack, Walgreens and many other stores that are household names in America.To those who follow the mobile payments space, this service has some interesting aspects. First, Google combines the Wallet with Google Offers, a set of electronic coupons also stored on your phone. Availing these offers is easy and near-automatic, thereby increasing the attraction of the service to customers. Google is planning other features such as membership suggestions and digital receipts. But the standout feature, which Google is trying to sell, lies in its security. At least to outsiders, including its potential customers, the feature looks more secure than competing offerings.To begin with, you do not display your cards like you do in a wallet. Your bank verifies your authenticity and details when you first put them on your phone, and you can de-activate them when you lose your device. It uses a technology called near-field communications (NFC), and it ensures that your data do not go out far. In competing technologies, the data goes out into the cloud. The NFC chip in the phone has several security features embedded and it is difficult for hackers to break into it.On the flipside, it can be used now only on the Nexus 4G phones from Sprint, but it is supposed to expand to other Android phones and operators as it goes international. Yet, it would remain as an Android feature, although Google has said that it could be extended to devices such as BlackBerry and iPhone. It would be difficult, but not impossible, to use it on a phone without an NFC chip. But the real significance of the Google service, and its strength and weakness, lies in one fact: the service is controlled from the device rather than by the operator in another location. This has not been the preferred approach so far. In the UK, which is rapidly becoming the centre of mobile payments, telcos are controlling and driving the service.Google Wallet is currently the easiest way to use mobile payments at retail merchants, where a substantial portion of credit card transactions take place. Other methods exist, but they are tied to one or other companies, whereas Wallet will work with all companies. The advent of Google Wallet would be a significant event in India.(This story was published in Businessworld Issue Dated 13-06-2011)
Read More
New Jersey-based Becton, Dickinson and Company (BD), the century-old medical device giant, is not new to India. Its first office in the country was set up in 1995. BD's India revenues, which topped $100 million in the past year, come from selling syringes, diagnostic kits, lab equipment and related gear used in healthcare. As growth prospects get bleaker at home, the company is looking for new growth avenues in emerging markets, and India, with its Rs 5,750- crore medical technology market, looks attractive. Now the $7.1-billion giant wants to ramp up its development and manufacturing operations in India — it is shifting production from Sweden to India. Company chairman and CEO Edward J. Ludwig speaks to BW's Noemie Bisserbe about the company's strategy and plans for India.The medical technology market in India is growing fast. But its needs are very different from that of the West. How are you addressing these needs?Let me go back. We have been in India since 1995, and our first efforts, frankly, were not that successful. I don't think we had a good sense of what the market needed. The need for safe injection, safe blood collection and evidence-based therapy are universal. But the way these are delivered here — through a combination of external forces such as NGOs, a federal policy level and a state policy level —is unique.We initially had one basic product — a two-piece syringe that was successful in southern parts of Europe. We moved manufacturing from Spain to India and started selling it here. But it turned out that the market here wasn't really a two-piece market, but rather a three-piece market. The two-piece doesn't have the rubber stopper and many markets prefer that for whatever reasons; but not this market.So, first we had the wrong product. Secondly, we exported a lot of expensive equipment that we paid duties on. So, it was not cost competitive. We can look back now and say we should have known better, but sometimes you just have to move in and learn from experience. FAST FACTS Established1897CEOEdward J. LudwigHeadquartersNew JerseyRevenues$7.1 billionEmployees29,100BusinessThree divisions: BDMedical, BD Diagnostics and BDBiosciencesKey ProductsNeedles, syringes, other medical devices and diagnostic systems, and reagents We are now developing products that are lower priced. Though they are still of very high quality, they may have a few features less and are easier to use. We are going to take a couple of years to fill in the pipeline of products here. We do not do any research and development yet in India. This situation will change in the next five years, and we will be doing more development in India. We will also expand our plant. It has some spare capacity, so we are moving some manufac-turing lines from Sweden to India. We will then export the products back to Europe.Is there a larger plan to make India a manufacturing hub?Not immediately. But over time, we will continue to expand. So, maybe over a period of 10 years, we will call India a hub for certain products.What is your pricing strategy for India?The simple thing is that we do not determine our prices. This is a very competitive place, and the market determines prices. We just have to make sure that our cost structure and value proposition is appropriate, so that we can get acceptable returns.Indian companies have now started developing indigenous devices at an affordable cost. How do you look at this new competition?There is a lot that we can learn in India. If you look in this building, you will find that most people who work here are generalists. When we start thinking about developing products here, we will have to start getting people with a medical background who understand technology. They will scan the market and look for such companies. Most innovations come from smaller companies. So we can partner with them or at some point, think about making acquisitions.Clearly, this is a threat. But I like to think of it as more of an opportunity too. We have always been very big on partnering with small entrepreneurs and licensing. What we have to offer is a global standard. Very often a small company has a great idea, but it does not have the resources to scale manufacturing or hire 200 sales executives. That is where synergies come in. We could acquire these companies or may partner with them for production and sales.What role can mobile and rapid diagnostic tools play to improve quality of care in India?Rapid diagnostic has been applied successfully in a number of settings, so I do not see why it could not be applied here as well. Probably, the only rapid test in India today is for pregnancy, although there are some tests for flu. We don't yet have adequate tests for diseases such as TB. Technology is struggling to keep up with the need.How important a market is India for you?The absolute size is not great. We are under $100 million revenues, but going forward, emerging markets will gain more importance, mainly India and China. Until two or three years ago, India was part of what we called Asia Pacific. Today, it reports directly to the head of international operations. We think of India as a region all by itself. India has the same status in our company as Europe. Our Indian business is growing at 20 per cent a year. In many parts of the world, including the US, we are holding our expenses flat because of economic realities. But in India, we are adding 100 people a year. We have a team of 450 people in India — twice the number of people we had three years ago. We are putting resources where we think the greatest opportunities are.(This story was published in Businessworld Issue Dated 12-04-2010)
Read More
If you are an apologist of nuclear energy, pause for a moment to consider these statistics. The world has 442 nuclear power plants that together produce 374 gigawatts (GW). Under construction are another 65, which will produce 62 GW. A typical plant also produces about 20 tonne radioactive waste in a year. This needs to be stored safely for near-eternity, if we think in practical terms. It does not need too much ingenuity to realise we would run out of space to store the waste if the industry expands rapidly.Look at India's nuclear ambitions. India gets 4 per cent of its electricity from nuclear energy. This will rise to 10 per cent by 2022 and 25 per cent by 2050, a plan that needs a consistent growth of 9.5 per cent a year for the next four decades. By then, India will be producing 470 GW of nuclear-based electricity, probably making it the largest user of nuclear power in the world. While many analysts consider this plan a piped ream, even partial success of it will generate huge waste. Given India's high population density, where will it store the waste? Fortunately, next- generation nuclear technologies can reduce the waste to manageable levels.For example, at the University of Texas in Austin, the Institute of Fusion Studies has been researching the problem. But instead of developing methods for safe burial of the waste, it looks at using it as a fuel in another reactor. It has designed a system that can burn 90 per cent of this nuclear waste, while also reducing the time the waste remains radio-active from centuries to decades. This techno-logy has attracted interest from all over the world, especially from India and China. In fact, the Department of Atomic Energy is planning to send a team to work in this lab.The institute has developed a hybrid nuclear reactor that combines nuclear fission and fusion to produce energy. Fusion is the way the Sun gets its energy; it happens when two atomic nuclei combine. In nuclear fission, an atomic nucleus splits into two or more. Both processes release enormous amounts of energy, but fusion is relatively safe as it produces far less radioactive waste than fission. But it is also more difficult to achieve controlled fusion.At the Institute of Fusion Studies and the University of Texas department of physics, scientists use fusion not as an energy source, but as a method to produce neutrons. It is the neutrons that split the nuclei, and lack of sufficient neutrons is the reason why we end up with the waste in the first place. As the byproducts of fission accumulate, they start absorbing neutrons without splitting. If we have a powerful external neutron source, the by-products of fission — which are highly radioactive — can be burned further. "We will never reach a situation where we have no waste, but we can reduce it to manageable levels," says Swadesh Mahajan, senior research scientist at the Institute of Fusion Research.The hybrid reactor, which combines fission and fusion in one device, has been a concept from the 1950s, but technology had not advanced enough then. Now hybrid reactor concepts have advanced to design and engineering stage. Three major groups work on this: Nuclear engineer Weston Stacey's group at Georgia Tech University, the Institute of Fusion Research in Texas University and the Institute of Plasma Physics at Hefei in China. All three have made major advances, but the Texas group has recently made a breakthrough that could lead to a real hybrid system soon.The group has designed Super X Divertor, a fusion device that is small enough to be lifted by a crane and put inside a blanket of fissile material. You can test this idea in two years, instead of the usual 10 years. There are, of course, several hurdles to cross before reaching a working hybrid, but experts do not consider any of them insurmountable. In fact, hybrid may become a necessity if we accumulate unprocessed waste the way the light-water reactors do at the moment.The beauty of the hybrid approach is that you need only one such reactor for every 15 conventional reactors to cut waste significantly. But the conventional reactor technology is itself going through a large shift. Almost all reactors are of second generation, which use Uranium 235 as fuel and krypton and barium as byproducts. They also produce elements such as plutonium that remain radioactive for hundreds of thousands of years. These are dangerous, and need enormous safety precautions. Most reactors have the spent but unprocessed fuel stored nearby. The Japanese Fukushima reactors would not have been so affected had they stored the waste as dry pellets elsewhere. Many such problems are taken care of in the fourth generation of reactors that will be tried over the next two decades.Three basic kinds of fourth-generation reactors are being developed: the gas cooled, water cooled and the fast reactors; all notable for their simplicity and safety features. For example, ‘pebble-bed' (gas-cooled) reactors have only two subsystems compared to 200 in light-water reactors.Fast reactors allow us to move away from using only uranium as the fuel source. "Physics does not tell us that only uranium can be used as a fissile material," says P.K. Iyengar, former chairman of India's Atomic Energy Commission. India is developing a fast reactor that will use thorium as a fuel. Thorium is not fissile, but can be converted into the fissile uranium 233 inside the reactor. Fast reactors can handle an accident like the loss of coolant much better. It generates negligible amounts of plutonium and very little long-lived waste. Fourth-generation reactors could be the future of nuclear energy. Says Robert Grimes, professor of materials physics at Imperial College in London: "We may need to enter a phase of reactor building in two decades. And for this to happen, we need to excite young people to take up nuclear engineering as a career now."
Read More
Larry Brubaker suffered a massive stroke in March and was hospitalised for nearly a month before being moved to an acute rehabilitation facility, then to a nursing home and finally to his own home near Sunbury, Pennsylvania. A former warehouse worker, Brubaker, 64, cannot walk, has little movement in any of his limbs, and has lost some powers of speech and hearing. He is being cared for by his wife Kay, who worked as a maid before retiring. What's unusual is who is instructing Kay on how to administer medications and other routine care for her husband, as well as helping her navigate the maze of local agencies that provide social services like nursing and physical therapy -- her insurance company, Geisinger Health Plan, which is part of Geisinger Health System. In his healthcare speech to Congress on Sept. 9, President Barack Obama cited Geisinger as a possible model for national reform. Based in central Pennsylvania, a rural region once dominated by coal mining, the system has recently earned a reputation for high-quality care at a lower-than-average cost. The White House refers to it as an "island of excellence" in the nation's murky healthcare waters. And unlike other highly touted health care providers, such as the Mayo Clinic, Geisinger isn't helped by well-heeled patients flying in from, say, Dubai. In fact, Geisinger serves 2.6 million people in 42 largely rural counties. Yet for all its success, the Geisinger formula won't easily catch on nationally. One of the main obstacles, according to numerous experts, are doctors themselves. Most physicians prefer or at least are accustomed to the longstanding fee-for-service model -- and likely would blanch at Geisinger's salary-based compensation. Even so, Geisinger Health System shows just how much can be done at a local level to curb runaway US health costs. House Calls Kay Brubaker, 65, finds caring for her husband a daunting challenge. She has to watch for signs of the aspiration or pneumonia that are typical with bedridden patients. Kay also has to take his blood pressure and administer the right doses of medications -- 13 of them. But she has lots of help. Geisinger's Medical Home programme works to keep patients like her husband out of hospitals and nursing homes, and in their own homes, where they can be cared for by relatives or visiting nurses at far lower costs. The programme's results are clear. Hospital admissions fell from 375 per 1,000 Medicare patients in 2006 to less than 350 the following year, saving 7 per cent in medical costs, while patients outside the programme rose to more than 400 admissions per 1,000 patients. To make the system work, Geisinger employs case managers like Jennifer Chikotas, a nurse who coordinates Brubaker's care. She is available by telephone 24/7 for advice or support -- and even arranges transportation to doctors' offices. "There's a lot of room for error or confusion," Chikotas said during a visit to the health plan's office in Selinsgrove, Pa. "Social Security, for example, wouldn't speak to Kay without the paperwork." Keeping a patient like Brubaker at home, most agree, does more than just lower costs. "The last place he needs to go back to is a hospital," Chikotas said. "It would open him up to more infection." Best Practices Established in 1915, Geisinger now has about 13,000 employees at 36 community practice sites and three hospitals. A private nonprofit organization, it reported revenue of $2.1 billion -- and an excess of revenue over expenses of $34.6 million -- for the fiscal year ended June 30, 2009. Medical authorities inside and outside Geisinger credit the system's performance to three factors: its salary-based compensation for physicians; an electronic medical records system that reduces the likelihood of treatment duplication by integrating the services of doctors, nurses and administrators; and best-practice protocols that require doctors to follow accepted standards for certain kinds of treatment. To cite one example: for a coronary artery bypass graft operation without a valve, Geisinger's average cost with a 5.3-day hospital stay was $88,055 in 2007. That compares with $370,502 over 8.1 days at Hahnemann University in Philadelphia, and $108,667 over 4.6 days at Lehigh Valley Health Network in Allentown, Pa., according to the Pennsylvania Health Care Containment Council. The ProvenCare best-practice protocol not only lowers costs but produces better health outcomes. For coronary artery bypass graft operations, for example, hospital readmissions fell 44 per cent in the first year of the ProvenCare operation. The complication rate dropped by 21 per cent and the average hospital stay shrank to 5.7 days from 6.2 days. In the field of perinatal care, the proportion of births by caesarian section has decreased to 23.5 per cent from a baseline of 36.6 per cent since the protocol was introduced for that specialty in October 2008, reducing the likelihood of a mother having subsequent C-sections. Role Models Larry McNeely, a healthcare advocate for the US Public Interest Research Group, which campaigns for citizens' rights, said national health reform should and could follow the Geisinger example. "I think it's a model that makes a lot of sense all over the country," he said. Like others, McNeely argues that the key to reforming the US health system is to change the way doctors are paid. The point would be to reward the quality of care, as Geisinger does, rather than the quantity of procedures, drugs or consultations. "The real barrier is the current payment system," McNeely said. "If you do what Geisinger does -- provide better quality -- you are not rewarded, you are punished. The reward goes to the doctors who order the most care." Geisinger's approximately 680 physicians are compensated with salaries and performance-related bonuses, rather than the traditional fee-for-service model. And they are rewarded for meeting ProvenCare standardrs. Winging it is not an option. In treating diabetes, for example, physicians are required to follow a nine-step checklist that is designed to ensure the best outcome for the patient -- and reduce future treatment costs. "We tell our doctors, 'If you do these nine things well, your patients' complications are diminished,'" said Dr. Howard Grant, Geisinger's chief medical officer. The protocols have allowed Geisinger to meet best-practice standards more often than most other systems, according to a study by the Pennsylvania Health Care Quality Alliance, a group of healthcare providers and insurers that seek to establish uniform standards. For heart-attack care, Geisinger performs recommended treatments 98 per cent of the time, compared with 81 per cent in Pennsylvania hospitals overall, and 79 per cent nationwide, the organization found. Geisinger is not without its critics, some of whom lambast the ProvenCare system as "cookbook medicine" that marginalizes a doctor's professional judgment -- a claim Geisinger dismisses. "It's not set in stone," Grant said. "But the presumption is that you will follow the pathway unless there is a compelling reason not to." Another potential barrier to widespread adoption of the Geisinger model is the expense of setting up an electronic medical records system. At Geisinger, all parties -- patients, physicians, nurses, administrators, and the internal insurance plan -- have timely access to each patient's medical history. The system, which has cost about $100 million since it was installed in the mid-1990s, is designed to prevent duplication of procedures and improve the coordination of care. For example, the electronic system allows emergency-room doctors to peruse a patient's history, allowing them to make a better-educated judgment about whether to admit that person. By contrast, paper records are typically not available to ER staff, so they are more likely to err on the side of caution and admit a patient, adding unnecessary costs. At Geisinger, inappropriate hospital admissions have fallen by 40 per cent since the system was introduced, Grant said. The electronic system also promises better care and lower costs in future by allowing doctors to be more proactive, Grant said. A rheumatologist, for example, can use the system to identify women who are at risk of osteoporosis, and then initiate preventive treatment. "We think that over time, we will see a significant reduction in the number of people who have hip fractures," Grant said. Part of the system is a facility called My Geisinger, which allows patients to email doctors, access their own medical records and make appointments. It also allows nurses like Erin Hubbert to deal with minor complaints that probably don't need the attention of a doctor or an office visit. At a Geisinger clinic, Hubbert was working at a computer terminal, instructing a patient who had used the system to notify the clinic of a case of diarrhea to drink clear fluids for 24 to 48 hours.
Read More
When the gadget world moves towards 3D, why should the transistors on which they are built be left behind? One good reason is that it is difficult to build 3D transistors. Also, it is risky. But Intel has chosen to ignore these arguments and build the world's first 3D transistors. They will appear towards the end of this year in Intel chips for the first time.Intel is a loner in this move towards 3D chips. The company wants to continue Moore's Law that predicts that the performance of integrated circuits will double every two years. Intel cannot increase the clock speed of its processors continually because the energy consumption becomes too high. It is rapidly reaching the limits of its current technology, and so, among other things, it decided to expand the transistor in another dimension.There is one major reason for this decision. It is getting increasingly difficult to shrink things any more without paying a heavy price. To get more space, Intel engineers built what is generally known as fin-field-effect transistor. It is named such — for the first time by some University of California professors — because the gate of the transistor consists of a vertical fin around which wraps the conducting channel for electrons. Intel does not call it fin-field transistor, though, calling it tri-gate transistor instead. It is named so because it has three gates: one on each side of the fin and one on top.Intel says that the thin three-dimensional fin with three gates lets it control the current far better than in a flat-surface channel. In practice, what this means is that more current can flow when it is in the ‘on' state and close to zero current when it is in the off state.This extra current translates to higher performance and the near-absence of current in the ‘off-state' translates to lower power requirements. It can also switch between the two states quickly, which also increases the performance. According to Intel, the performance can increase by 37 per cent at low voltage and the energy consumption can decrease by 50 per cent.Intel likens the move towards 3D transistor like building skyscrapers when we run out of space on the ground. The fins are very thin and go upward, and so they can be packed close together. However, in spite of Intel's confidence with its research and development, other semiconductor firms think 3D transistor technology still has some way to go. To improve performance, they are instead pursuing a method first implemented by IBM in 1998, called Silicon On Insulator (SOI) technology. In essence, it involves the use of an insulator below the silicon junction. This method is compatible with current manufacturing techniques and is thus less risky, but Intel has chosen the riskier and more powerful option.Along with 3D, Intel has also announced a shift to 22-nanometer technology. These two combined should give a considerable boost to the performance of its chips. It remains to be seen how the chips will perform in practice.Intel has had a few hiccups of late, the latest one a flaw in the Sandy Bridge processor design discovered early this year. However, the tri-gate transistor gives Intel an option in the mobile world, where it can provide high performance chips without too much increase in energy consumption. It can also increase its dominance in the PC world with a substantial boost in chip power. And it can do this while continuing the parallel development of multicore chips. Intel is yet to explain plenty of things. So it remains to be seen how good they will be in mobile phones when compared to ARM chips. It remains to be seen what the consumer will buy.(This story was published in Businessworld Issue Dated 16-05-2011)
Read More
Starting from sometime in the past century, when human beings became aware that solar energy is non-polluting and abundant, companies and research and development institutions have been spending considerable money and energy to make it cheap as well. Engineers have tried a slew of approaches to harvest solar energy, but with incremental improvements. Now there is a solar energy technology, nantenna, that promises to deliver a magnitude increase in performance — if it goes from a prototype to a commercial version.Developed by a team of scientists led by Patrick Pinhero from the University of Missouri, it has a new approach towards using solar energy. Solar cells, no matter what they are made of, use the property of some materials to produce electricity — called the photoelectric effect — when exposed to sunlight. Another kind of solar energy technology, solar thermal, uses the Sun's energy to heat water and then produce electricity through a turbine. The Missouri invention uses a series of tiny antennas that can absorb Sun's radiation and generate electricity. There is, however, a crucial difference here compared to photovoltaic cells: the antenna can use 90 per cent of the radiation, while photovoltaic cells can use around 20 per cent.It is a revolutionary technology, even though it is early days for it, and the scientists think it will take five years before it can become a commercial device. Yet, there are many uses for it in the meantime. It could produce electricity from waste heat in factories. It could detect contraband materials in airports. You could use them in the skin of electronic devices for continual charging. The nantenna has its uses in security applications as well, and some of these could make their way to the world before a large-scale energy harvesting device does. But it can become a game-changer if it ever makes it to the power-generation market. And there are no serious theoretical bottlenecks obvious now.The idea of a nantenna — a short form for nano-antenna — originated in the 1970s. Tiny antennas of the right material can absorb radiation of specific frequencies proportional to their size. By designing antennas of different sizes, one can design systems that can absorb radiation of different frequencies. The absorbed radiation produces an alternating current that is converted to direct current using a rectifier. However, there are enormous technological challenges to designing tiny antennas that can absorb a visible and infrared radiation from the Sun. Pinhero and his team are supposed to have surmounted several such challenges and developed a prototype. They were assisted by engineers from the University of Colorado, who developed a diode to act as a rectifier, and private firm MicroContinuum in Massachusetts, which is developing high-volume manufacturing process.The biggest advantage of this technology is it can use radiation that lies outside the scope of photovoltaics. A substantial amount of radiation reaches the Earth's surface between wavelengths of 800 and 900 nanometeres, even when it is cloudy, but it is very difficult to design solar cells that can use this radiation. You can design panels with antennas that absorb Sun's radiation on one side and the Earth's radiated heat on the other. As the Earth radiates heat at night, the device could produce some electricity even at night. Pinhero's team has fabricated the device on a flexible substrate, making it ideal for installations on rooftops and other places. So it pays to keep a watch on the development of nantennas. They could power the world one day.(This story was published in Businessworld Issue Dated 30-05-2011)
Read More
