Source | Modern Mechanix
Archive for August, 2008
In a technological advance that opens up new possibilities in the fields of robotics and wearable computing, researchers at the University of Tokyo have developed a stretchable, rubbery material that conducts electricity and can be incorporated into electronic devices.The researchers — led by assistant professor Takao Someya of the University of Tokyo — were able to create elastic electronic circuits that could be stretched up to 1.7 times their original size without affecting performance, thanks to conductive wires made from a new carbon nanotube-polymer composite they developed.
In recent years, scientists have made advances in blending carbon nanotubes (good conductors of electricity) with polymers to make flexible conductive materials, but success has been limited because nanotubes tend to cluster together, causing the composite to harden when too many nanotubes are added. The University of Tokyo researchers were able to overcome this hurdle by mixing the nanotubes with an ionic liquid containing charged particles that keep the nanotubes evenly distributed and prevent them from clumping together. The result is a stretchable material that conducts electricity more than 500 times better than other commercially available carbon nanotube-polymer blends.
With the list of potential uses of stretchable electronic circuits limited only by the imagination, the researchers envision applications ranging from high-tech suits that enhance athletic performance and monitor the wearer’s physical condition, to soft machines with flexible mechanical parts. For robots, elastic electronic circuits will enable layers of soft, sensor-laden skin to be stretched tightly across the curves of their bodies, giving them both a more lifelike appearance and greater sensitivity to touch.
The research results were published in the online edition of Science (August 8).
Source | PinkTentacle
Description of the Robotic Chair
The Robotic Chair (1984 – 2006) is a generic-looking wooden chair with the capacity to fall apart and put itself back together. With shuddering force the chair collapses to the floor then with persistence and determination proceeds to seek out its parts and upright itself. The Robotic Chair is distinguished in the world of objects for its capacity to elicit empathy, compassion and hope.
As an object, the chair has been a constant and trustworthy partner in the history of civil society. We depend on the chair to support our bodies as we depend upon the earth beneath our feet. The Robotic Chair stands in for the individual and a society over the course of a lifetime – falling apart, falling down, gathering oneself together, picking oneself up, again and again. The Robotic Chair articulately and concisely reminds us on a grand scale that there is magic – that there is hope.
The Robotic Chair seat houses a custom robot charged with the ambitious task of locating the scattered parts (legs and back), reassembling itself, then restoring itself to its former chair status. The chair acts autonomously guided by an overhead vision system and is not dependent on viewer presence or interaction to perform. The Robotic Chair is a collaborative project by artist Max Dean, professor/entrepreneur Raffaello D’Andrea and artist/industrial designer Matt Donovan.
Source | Robotic Chair
This “microscopic microscope” operates without lenses but has the magnifying power of a top-quality optical microscope, can be used in the field to analyze blood samples for malaria or check water supplies for giardia and other pathogens, and can be mass-produced for around $10.”The whole thing is truly compact–it could be put in a cell phone–and it can use just sunlight for illumination, which makes it very appealing for Third-World applications,” says Changhuei Yang, assistant professor of electrical engineering and bioengineering at Caltech, who developed the device, dubbed an optofluidic microscope, along with his colleagues at Caltech.
The new instrument combines traditional computer-chip technology with microfluidics–the channeling of fluid flow at incredibly small scales. An entire optofluidic microscope chip is about the size of a quarter, although the part of the device that images objects is only the size of Washington’s nose on that quarter.
“Our research is motivated by the fact that microscopes have been around since the 16th century, and yet their basic design has undergone very little change and has proven prohibitively expensive to miniaturize. Our new design operates on a different principle and allows us to do away with lenses and bulky optical elements,” says Yang.
The fabrication of the microscopic chip is disarmingly simple. A layer of metal is coated onto a grid of charge-coupled device (CCD) sensor (the same sensors that are used in digital cameras). Then, a line of tiny holes, less than one-millionth of a meter in diameter, is punched into the metal, spaced five micrometers apart. Each hole corresponds to one pixel on the sensor array. A microfluidic channel, through which the liquid containing the sample to be analyzed will flow, is added on top of the metal and sensor array. The entire chip is illuminated from above; sunlight is sufficient.
When the sample is added, it flows–either by the simple force of gravity or drawn by an electric charge–horizontally across the line of holes in the metal. As cells or small organisms cross over the holes, one hole after another, the objects block the passage of light from above onto the sensor below. This produces a series of images, consisting of light and shadow, akin to the output of a pinhole camera.
Because the holes are slightly skewed, so that they create a diagonal line with respect to the direction of flow, the images overlap slightly. All of the images are then pieced together to create a surprisingly precise two-dimensional picture of the object.
Source | MedGadget
Researchers have found a cheap and easy way to store the energy made by solar power.
By Kevin Bullis
Researchers have made a major advance in inorganic chemistry that could lead to a cheap way to store energy from the sun. In so doing, they have solved one of the key problems in making solar energy a dominant source of electricity.
Daniel Nocera, a professor of chemistry at MIT, has developed a catalyst that can generate oxygen from a glass of water by splitting water molecules. The reaction frees hydrogen ions to make hydrogen gas. The catalyst, which is easy and cheap to make, could be used to generate vast amounts of hydrogen using sunlight to power the reactions. The hydrogen can then be burned or run through a fuel cell to generate electricity whenever it’s needed, including when the sun isn’t shining.
Solar power is ultimately limited by the fact that the solar cells only produce their peak output for a few hours each day. The proposed solution of using sunlight to split water, storing solar energy in the form of hydrogen, hasn’t been practical because the reaction required too much energy, and suitable catalysts were too expensive or used extremely rare materials. Nocera’s catalyst clears the way for cheap and abundant water-splitting technologies.
Nocera’s advance represents a key discovery in an effort by many chemical research groups to create artificial photosynthesis–mimicking how plants use sunlight to split water to make usable energy. “This discovery is simply groundbreaking,” says Karsten Meyer, a professor of chemistry at Friedrich Alexander University, in Germany. “Nocera has probably put a lot of researchers out of business.” For solar power, Meyer says, “this is probably the most important single discovery of the century.”
The new catalyst marks a radical departure from earlier attempts. Researchers, including Nocera, have tried to design molecular catalysts in which the location of each atom is precisely known and the catalyst is made to last as long as possible. The new catalyst, however, is amorphous–it doesn’t have a regular structure–and it’s relatively unstable, breaking down as it does its work. But the catalyst is able to constantly repair itself, so it can continue working.
In his experimental system, Nocera immerses an indium tin oxide electrode in water mixed with cobalt and potassium phosphate. He applies a voltage to the electrode, and cobalt, potassium, and phosphate accumulate on the electrode, forming the catalyst. The catalyst oxidizes the water to form oxygen gas and free hydrogen ions. At another electrode, this one coated with a platinum catalyst, hydrogen ions form hydrogen gas. As it works, the cobalt-based catalyst breaks down, but cobalt and potassium phosphate in the solution soon re-form on the electrode, repairing the catalyst.
Nocera created the catalyst as part of a research program whose goal was to develop artificial photosynthesis that works more efficiently than photosynthesis and produces useful fuels, such as hydrogen. Nocera has solved one of the most challenging parts of artificial photosynthesis: generating oxygen from water. Two more steps remain. One is replacing the expensive platinum catalyst for making hydrogen from hydrogen ions with a catalyst based on a cheap and abundant metal, as Nocera has done with the oxygen catalyst.
Finding a cheaper catalyst for making hydrogen shouldn’t be too difficult, says John Turner, a principal investigator at the National Renewable Energy Laboratory, in Golden, CO. Indeed, Nocera says that he has promising new materials that might work, and other researchers also have likely candidates. The second remaining step in artificial photosynthesis is developing a material that absorbs sunlight, generating the electrons needed to power the water-splitting catalysts. That will allow Nocera’s catalyst to run directly on sunlight; right now, it runs on electricity taken from an outlet.
There’s also still much engineering work to be done before Nocera’s catalyst is incorporated into commercial devices. It will, for example, be necessary to improve the rate at which his catalyst produces oxygen. Nocera and others are confident that the engineering can be done quickly because the catalyst is easy to make, allowing a lot of researchers to start working with it without delay. “The beauty of this system is, it’s so simple that many people can immediately jump on it and make it better,” says Thomas Moore, a professor of chemistry and biochemistry at Arizona State University.
Source | Technology Review