Paint-on Solar Cells: Let Walls Power Your Home

Gone are the days when we used to paint our walls with glossy paints and then with vinyls. A new technique will change the face of the walls and allow you to beautify your walls with solar cells.

The technique has been developed by scientists at the New Jersey Institute of technology. These scientists claim to have developed a way to create a solar cell that can be painted on flexible plastic sheets. To achieve solar cells these scientists have used a complex combination of carbon nanotubes and carbon Buckyball molecules to create a series of snake-like patterns which can conduct electricity.

When sunlight falls on the surface of this paint it excites the polymer backing, which in turn releases electrons. Buckyball molecules catch electrons but they cannot transmit them. For transmitting electrons in a flow scientists have used carbon nanotubes. Carbon nanotubes act as a copper wire to conduct the free flowing electrons, thus generating electricity.

Scientists also hope that the technique will not be expensive and will be easy to implement. Once the material is painted on walls, ceiling or on the roof top it can provide enough electricity to power your home. This technology will someday allow homeowners to paint sheets of the material with a machine that will not be much different from an ink-jet printer and all you will have to do is just paste them on your walls and enjoy free power.

Nanotechnology-based Flexible Hydrogen Sensors

With hydrogen vehicles already embracing carbon-reduction footprints, global warming seems to be moving a step further with its nobility its sensors.

The now available hydrogen sensors may soon be replaced by a newly developed flexible sensor, which is not only comparatively cheaper but also explores the world of nano-technology! Thanks the scientists at the U.S. Argonne National Laboratory.

What could help make the sensors cheaper is the use of only palladium nanoparticles instead of pure palladium.

But, of course this will not compromise on its pure-palladium-like efficiency. To add to, it can be used in a number of applications ranging from aircraft to portable electronics. To detect a hydrogen leakage caused by even tiny pinholes in the space shuttle pipe, the new technology can be of great use.

This is how the new flexible hydrogen sensor is fabricated:

The new sensing devices is fabricated by using a two-step process separated by hig] h and low temperatures. First, at around 900 degrees C, scientists grow SWNTs [single-walled carbon nanotubeson a silicon substrate using chemical vapor deposition. Then, scientists transfer the SWNTs onto a plastic substrate at temperatures lower than 150 degrees C using a technique called dry transfer printing.

And the result:-

The new sensors are highly sensitive, thus fast responding and quick recovering. The plastic sheets it uses help reduce the overall weight, increasing the mechanical flexibility as well as shock resistance.

Thus, its wide range - as well as sensitive and affordable - applications seem to be making the hydrogen (or eco-friendly) vehicles gradually affordable to more and more people who are environmentally conscious, but could not serve it because of the hard-to-meet costs.

Low cost Linux virtual hosting

Linux is a free open source operating system based on the Unix operating system and is a popular alternative to others (such as Microsoft) due to it's versatility. Additionally, Linux servers which most often run a platform of Linux, Apache, MySQL, Perl/PHP/Python have become very popular with web developers and in turn many businesses have websites and systems run on this software. In fact, IBM has chosen Linux to be the operating system on their Sequioa supercomputer due to be unveiled in 2011.

Linux virtual hosting has emerged as a service for companies running their IT systems on the Linux platform. It offers them the opportunity to outsource their IT requirements to specialised hosting companies who run virtual servers - server machines which have been compartmentalised, with each compartment running its own operating system and acting as an individual server.

This can be a very low cost solution which can really benefit small to medium businesses who are trying to lower overheads as we emerge from the recent recession. Plus, the nature of the virtual hosting system and the Linux platform allow perfectly for scalability as your business grows. As your needs increase, your hosting company can increase the server space available and add extra software applications, updates etc as you require them.

Switchlink can offer you Linux server hosting from as little as £5.99 a month. Find out more on their website at www.switchlink.co.uk

Taming thermonuclear plasma with a snowflake

This is a "snowflake" divertor -- a novel plasma-material interface is realized in the National Spherical Torus Experiment.

Credit: V. Soukhanovskii, Lawrence Livermore National Laboratory

Physicists working on the National Spherical Torus Experiment (NSTX) at the Princeton Plasma Physics Laboratory are now one step closer to solving one of the grand challenges of magnetic fusion researchhow to reduce the effect that the hot plasma has on fusion machine walls (or how to tame the plasma-material interface). Some heat from the hot plasma core of a fusion energy device escapes the plasma and can interact with reactor vessel walls. This not only erodes the walls and other components, but also contaminates the plasmaall challenges for practical fusion. One method to protect machine walls involves divertors, chambers outside the plasma into which the plasma heat exhaust (and impurities) flow. A new divertor concept, called the "snowflake," has been shown to significantly reduce the interaction between hot plasma and the cold walls surrounding it.

Strong magnetic fields shape the hot plasma in the form of a donut in a magnetic fusion plasma reactor called a tokamak. As confined plasma particles move along magnetic field lines inside the tokamak, some particles and heat escape because of instabilities in the plasma. Surrounding the hot plasma is a colder plasma layer, the scrape-off layer, which forms the plasma-material interface. In this layer, escaped particles and heat flow along an "open" magnetic field line to a separate part of the vessel and enter a "divertor chamber." If the.

plasma striking the divertor surface is too hot, melting of the plasma-facing components and loss of coolant can occur. Under such undesirable conditions, the plasma-facing component lifetime would also be an issue, as they would tend to wear off too quickly.

While the conventional magnetic X-point divertor concept has existed for three decades, a very recent theoretical idea and supporting calculations by Dr. D.D. Ryutov from Lawrence Livermore National Laboratory have indicated that a novel magnetic divertorthe "snowflake divertor"would have much improved heat handling characteristics for the plasma-material interface. The name is derived from the appearance of magnetic field lines forming this novel magnetic interface.

This magnetic configuration was recently realized in NSTX and fully confirmed the theoretical predictions. The snowflake divertor configuration was created by using only two or three existing magnetic coils. This achievement is an important result for future tokamak reactors that will operate with few magnetic coils. Because the snowflake divertor configuration flares the scrape-off layer at the divertor surface, the peak heat load is considerably reduced, as was confirmed by the divertor heat flux on NSTX. The plasma in the snowflake divertor, instead of heating the divertor surface on impact, radiated the heat away, cooled down and did not erode the plasma-facing components as much, thus extending their lifetime. Plasma TV images show more divertor radiation in the snowflake divertor plasmas in comparison with the standard plasmas. Importantly, the snowflake divertor did not have an impact on the high performance and confinement of the high-temperature core plasma, and even reduced the impurity contamination level of the main plasma.

These highly encouraging results provide further support for the snowflake divertor as a viable plasma-material interface for future tokamak devices and for fusion development applications.

Will We Hear The Light??

University of Utah bioengineer Richard Rabbitt led two new studies that made a surprising discovery: an invisible wavelength of infrared light can make rat heart cells beat and cause toadfish inner-ear cells to send signals to the brain. The discovery points the way to possible development of implanted devices that can use infrared light instead of electric signals to help deaf people hear -- a new form of cochlear implant -- help blind people see and treat movement and balance disorders.

Credit: Lee Siegel, University of Utah.

University of Utah researchers used invisible infrared light to make rat heart cells contract and toadfish inner-ear cells send signals to the brain. The discovery someday might improve cochlear implants for deafness and lead to devices to restore vision, maintain balance and treat movement disorders like Parkinson's.

"We're going to talk to the brain with optical infrared pulses instead of electrical pulses," which now are used in cochlear implants to provide deaf people with limited hearing, says Richard Rabbitt, a professor of bioengineering and senior author of the heart-cell and inner-ear-cell studies published this month in The Journal of Physiology
The studies � funded by the National Institutes of Health � also raise the possibility of developing cardiac pacemakers that use optical signals rather than electrical signals to stimulate heart cells. But Rabbitt says that because electronic pacemakers work well, "I don't see a market for an optical pacemaker at the present time".

The scientific significance of the studies is the discovery that optical signals � short pulses of an invisible wavelength of infrared laser light delivered via a thin, glass optical fiber � can activate heart cells and inner-ear cells correlation to balance and hearing.

In addition, the research showed infrared activates the heart cells, called cardiomyocytes, by triggering the movement of calcium ions in and out of mitochondria, the organelles or components within cells that convert sugar into usable energy. The same process appears to occur when infrared light stimulates inner-ear cells.

Infrared light can be felt as heat, raising the possibility the heart and ear cells were activated by heat rather than the infrared radiation itself. But Rabbitt and his colleagues did "elegant experiments" to show the cells indeed were activated by the infrared radiation, says a commentary in the journal by Ian Curthoys of the University of Sydney, Australia.

Curthoys writes that the research provides "stunningly bright insight" into events within inner-ear cells and "has great potential for future clinical application."

Shedding Infrared Light on Inner-Ear Cells and Heart Cells .

The low-power infrared light pulses in the study were generated by a diode � "the same thing that's in a laser pointer, just a different wavelength," Rabbitt says.

The researchers exposed the cells to infrared light in the laboratory. The heart cells in the study were newborn rat heart muscle cells called cardiomyocytes, which make the heart pump. The inner-ear cells are hair cells, and came from the inner-ear organ that senses motion of the head. The hair cells came from oyster toadfish, which are well-establish models for comparison with human inner ears and the sense of balance.

Inner-ear hair cells "convert the mechanical vibration from sound, gravity or motion into the signal that goes to the brain" via adjacent nerve cells, says Rabbitt.

Using infrared radiation, "we were stimulating the hair cells, and they dumped neurotransmitter onto the neurons that sent signals to the brain," Rabbitt says.

He believes the inner-ear hair cells are activated by infrared radiation because "they are full of mitochondria, which are a primary target of this wavelength".

The infrared radiation affects the flow of calcium ions in and out of mitochondria � something shown by the companion study in neonatal rat heart cells.

That is important because for "excitable" nerve and muscle cells, "calcium is like the trigger for making these cells contract or release neurotransmitter," says Rabbitt.

The heart cell study observed that an infrared pulse lasting a mere one-5,000th of a second made mitochondria rapidly suck up calcium ions within a cell, then slowly release them back into the cell � a cycle that makes the cell contract.

"Calcium does that normally," says Rabbitt. "But it's normally controlled by the cell, not by us. So the infrared radiation gives us a tool to control the cell. In the case of the [inner-ear] neurons, you are controlling signals going to the brain. In the case of the heart, you are pacing contraction".

New Possibilities for Optical versus Electrical Cochlear Implants
Rabbitt believes the research � including a related study of the cochlea last year � could lead to better cochlear implants that would use optical rather than electrical signals.

Existing cochlear implants convert sound into electrical signals, which typically are transmitted to eight electrodes in the cochlea, a part of the inner ear where sound vibrations are converted to nerve signals to the brain. Eight electrodes can deliver only eight frequencies of sound, Rabbitt says.

"A healthy adult can hear more than 3,000 different frequencies. With optical stimulation, there's a possibility of hearing hundreds or thousands of frequencies instead of eight. Perhaps someday an optical cochlear implant will allow deaf people to once again enjoy music and hear all the nuances in sound that a hearing person would enjoy".

Unlike electrical current, which spreads through tissue and cannot be focused to a point, infrared light can be focused, so numerous wavelengths (corresponding to numerous frequencies of sound) could be aimed at different cells in the inner ear.

Nerve cells that send sound signals from the ears to the brain can fire more than 300 times per second, so ideally, a cochlear implant using infrared light would be able to perform as well. In the Utah experiments, the scientists were able to apply laser pulses to hair cells to make adjacent nerve cells fire up to 100 times per second. For a cochlear implant, the nerve cells would be activated within infrared light instead of the hair cells.

Rabbitt cautioned it appears to be five to 10 years before the development of cochlear implants that run optically. To be practical, they need a smaller power supply and light source, and must be more power efficient to run on small batteries like a hearing aid.

Optical Prosthetics for Movement, Balance and Vision Disorders
Electrical deep-brain stimulation now is used to treat movement disorders such as Parkinson's disease and "essential tremor, which causes rhythmic movement of the limbs so it becomes difficult to walk, function and eat," says Rabbitt.

He is investigating whether optical rather than electrical deep-brain stimulation might increase how long the therapy is effective.

Rabbitt also sees potential for optical implants to treat balance disorders.

"When we get old, we shuffle and walk carefully, not because our muscles don't work but because we have trouble with balance," he says. "This technology has potential for restoring balance by restoring the signals that the healthy ear sends to the brain about how your body is moving in space".

Optical stimulation also might provide artificial vision in people with retinitis pigmentosa or other loss of retinal cells � the eye cells that detect light and color � but who still have the next level of cells, known as ganglia, Rabbitt says.

"You would wear glasses with a camera [mounted on the frames] and there would be electronics that would convert signals from the camera into pulses of infrared radiation that would be patterned onto the diseased retina that normally does not respond to light but would respond to the pulsed infrared radiation" to create images, he says.

Hearing and vision implants that use optical rather than electrical signals do not have to penetrate the brain or other nerve tissue because infrared light can penetrate "quite a bit of tissue," so devices emitting the light "have potential for excellent biocompatibility," Rabbitt says. "You will be able to implant optical devices and leave them there for life".