ATHIRA
ELECTRONIC COTTON
A group of researchers in the United States, Italy, and France have invented transistors made from cotton fibers. They envision such devices being woven into clothing capable of measuring pollutants, T-shirts that display information, and carpets that sense how many people are crossing them. "We want to create a seamless interface between electronics and textiles," says Juan Hinestroza, director of the Textiles Nanotechnology Laboratory at Cornell University, in Ithaca, N.Y.
Instead of attaching sensors or processors to clothing after the garments are fully formed, it would be more effective to incorporate such devices directly into the fabrics, says Annalisa Bonfiglio, an EE professor at the University of Cagliari, in Italy, whose student Giorgio Mattana worked on the cotton in Hinestroza's lab.
The cellulose that makes up cotton is naturally insulating, so to make a fiber conductive, the team coated each strand with gold nanoparticles. They then added a thin layer of a conductive polymer known as PEDOT. The fibers proved to be about a thousand times as conductive as plain cotton, while their mechanical properties remained almost unchanged. They were slightly stiffer but more elastic than untreated fibers, Bonfiglio says. The team demonstrated the treated cotton's conductivity by making a simple circuit, knotting one end to a battery and the other to an LED.
To show the versatility of the process, the researchers created two types of devices: an organic electrochemical transistor and an organic field-effect transistor. For the electrochemical version, conductive cotton fibers were used as source, drain, and gate electrodes. To complete the transistor, the team needed to create a semiconductor. They achieved this by doping the conductive polymer with poly(styrenesulfonate), a polymer commonly used to make proton exchange membranes in fuel cells. After a soak in the second polymer, the cotton fiber was coated with ethylene glycol to make it waterproof.
The field-effect transistor also begins with a conductive cotton strand dipped in the semiconducting polymer, which in this case acts as the gate electrode. But the fiber is then given a thin coat of polymer film that acts as a dielectric, followed by a coat of pentacene, another semiconductor polymer film.
Treating the cotton with these various substances is not as
complicated as it sounds; Bonfiglio says it's comparable to dyeing the
material. Still, don't expect to see underpants doubling as MP3
players anytime soon. The speed of electrons in these transistors is
relatively low compared to that of silicon circuits, says Bonfiglio.
"For the moment, I think the most realistic application is in the sensor area," she says. For instance, firefighters' uniforms might be able to detect dangerous chemicals, while security personnel could be alerted to airborne signatures of explosives or drugs. Garments might also monitor heart rate or perspiration. Inside homes and businesses, fabrics—in the form of carpeting, wall coverings, and upholstery—could keep track of humidity levels and allergens.
"If you think about how many fibers you have in your T-shirt, and how many interconnections you have between the weft and the warp of the fabric, you could get pretty decent computing power," says Hinestroza.
AJAY PAUL
Two days before the Delhi Auto Expo, Bajaj Auto showcased the RE60, an “intra-city passenger carrier”. It was initially meant to be a low-cost small car, developed in collaboration with the Renault-Nissan combine, to take on the Nano. What has finally come out, according to Bajaj Auto, is not a challenger to the Nano so much as a product that seeks to replace the five million or so three-wheelers in the country. In fact, Rajiv Bajaj, the managing director of Bajaj Auto, has made it very clear that the RE60 is not a car. He knows that once it is positioned as a replacement for three-wheelers, the RE60 will never be perceived as a car. Clearly, Bajaj Auto is prepared to stay away from the car market for some more time. That may not be a bad thing. While there is cut-throat competition in the small car market, a small public transport vehicle is a uniquely emerging-market product, and that’s why large automobile companies – Japanese, Korean, American or European – have not bothered to invest in this direction. It’s not their core competence. That shields the RE60 from global automobile makers for the time being.
VIVEK KANISSERY
ROLL LAPTOP
the laptop has gone a long way from its initial state to become from thick
to normal to thin to slim to ultra slim..and people wondered what next..how much more portable is it going to get..!!here it is..
a laptop that can be rolled up and put into a handbag with ease!!..surely a cool idea..use the laptop when needed,roll it when done with the work and put it into the bag!!
have a look
see this
REESHMA
ELECTRIC MOTOR FROM A SINGLE MOLECULE By Jason Palmer Science and technology reporter, BBC News
ELECTRONIC COTTON
A group of researchers in the United States, Italy, and France have invented transistors made from cotton fibers. They envision such devices being woven into clothing capable of measuring pollutants, T-shirts that display information, and carpets that sense how many people are crossing them. "We want to create a seamless interface between electronics and textiles," says Juan Hinestroza, director of the Textiles Nanotechnology Laboratory at Cornell University, in Ithaca, N.Y.
Instead of attaching sensors or processors to clothing after the garments are fully formed, it would be more effective to incorporate such devices directly into the fabrics, says Annalisa Bonfiglio, an EE professor at the University of Cagliari, in Italy, whose student Giorgio Mattana worked on the cotton in Hinestroza's lab.
The cellulose that makes up cotton is naturally insulating, so to make a fiber conductive, the team coated each strand with gold nanoparticles. They then added a thin layer of a conductive polymer known as PEDOT. The fibers proved to be about a thousand times as conductive as plain cotton, while their mechanical properties remained almost unchanged. They were slightly stiffer but more elastic than untreated fibers, Bonfiglio says. The team demonstrated the treated cotton's conductivity by making a simple circuit, knotting one end to a battery and the other to an LED.
To show the versatility of the process, the researchers created two types of devices: an organic electrochemical transistor and an organic field-effect transistor. For the electrochemical version, conductive cotton fibers were used as source, drain, and gate electrodes. To complete the transistor, the team needed to create a semiconductor. They achieved this by doping the conductive polymer with poly(styrenesulfonate), a polymer commonly used to make proton exchange membranes in fuel cells. After a soak in the second polymer, the cotton fiber was coated with ethylene glycol to make it waterproof.
The field-effect transistor also begins with a conductive cotton strand dipped in the semiconducting polymer, which in this case acts as the gate electrode. But the fiber is then given a thin coat of polymer film that acts as a dielectric, followed by a coat of pentacene, another semiconductor polymer film.
Photo:Textiles Nanotechnology Laboratory at Cornell
University
University
Nice Threads: Conductive cotton ties in to a simple circuit.
"For the moment, I think the most realistic application is in the sensor area," she says. For instance, firefighters' uniforms might be able to detect dangerous chemicals, while security personnel could be alerted to airborne signatures of explosives or drugs. Garments might also monitor heart rate or perspiration. Inside homes and businesses, fabrics—in the form of carpeting, wall coverings, and upholstery—could keep track of humidity levels and allergens.
"If you think about how many fibers you have in your T-shirt, and how many interconnections you have between the weft and the warp of the fabric, you could get pretty decent computing power," says Hinestroza.
AJAY PAUL
|
Two days before the Delhi Auto Expo, Bajaj Auto showcased the RE60, an “intra-city passenger carrier”. It was initially meant to be a low-cost small car, developed in collaboration with the Renault-Nissan combine, to take on the Nano. What has finally come out, according to Bajaj Auto, is not a challenger to the Nano so much as a product that seeks to replace the five million or so three-wheelers in the country. In fact, Rajiv Bajaj, the managing director of Bajaj Auto, has made it very clear that the RE60 is not a car. He knows that once it is positioned as a replacement for three-wheelers, the RE60 will never be perceived as a car. Clearly, Bajaj Auto is prepared to stay away from the car market for some more time. That may not be a bad thing. While there is cut-throat competition in the small car market, a small public transport vehicle is a uniquely emerging-market product, and that’s why large automobile companies – Japanese, Korean, American or European – have not bothered to invest in this direction. It’s not their core competence. That shields the RE60 from global automobile makers for the time being.
VIVEK KANISSERY
ROLL LAPTOP
the laptop has gone a long way from its initial state to become from thick
to normal to thin to slim to ultra slim..and people wondered what next..how much more portable is it going to get..!!here it is..
a laptop that can be rolled up and put into a handbag with ease!!..surely a cool idea..use the laptop when needed,roll it when done with the work and put it into the bag!!
have a look
see this
REESHMA
ELECTRIC MOTOR FROM A SINGLE MOLECULE By Jason Palmer Science and technology reporter, BBC News
Researchers have created the smallest electric motor ever devised.
The motor, made from a single molecule just a billionth of a metre across, is reported in Nature Nanotechnology.The minuscule motor could have applications in both nanotechnology and in medicine, where tiny amounts of energy can be put to efficient use.
Miniature uses
The butyl methyl sulphide molecule was placed on a clean copper surface, where its single sulphur atom acted as a pivot.
The tip of a scanning tunnelling microscope - a tiny pyramid with a point just an atom or two across - was used to funnel electrical charge into the motor, as well as to take images of the molecule as it spun.It spins in both directions, at a rate as high as 120 revolutions per second.But averaged over time, there is a net rotation in one direction.
By modifying the molecule slightly, it could be used to generate microwave radiation or to couple into what are known as nano-electromechanical systems, Dr Sykes said.
"The next thing to do is to get the thing to do work that we can measure - to couple it to other molecules, lining them up next to one another so they're like miniature cog-wheels, and then watch the rotation propagation down the chain," he said.
As well as forming a part of the tiniest machines the world has ever seen, such minute mechanics could be useful in medicine - for example, in the controlled delivery of drugs to targeted locations.
The butyl methyl sulphide molecule whips round an axis defined by its single sulphur atom (blue)
ARUN JOSE
ARUN JOSE
India ahead of China in quality of scientific papers
It is steadily gaining in global leadership in research areas, says study.....
India is well ahead of China in the quality of its scientific papers, though it lags in growth in the number of papers, a study has revealed.
The quality of papers is determined by the number of citations per article, and this has gone by 2 to 2.7 over the past five years for papers from Indian scientists, says the study done by Elsevier, a world-leader in medical and scientific publications. On the other hand, articles from Chinese scientists are found to have a citation factor of 2.2.
read more at THE HINDU.............
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