A New Year and Some New TechJanuary 8, 2009 By: Melanie Martella, Sensors
Well, a Happy New Year to all of you! Welcome to 2009 which will be, I hope, a significant improvement over 2008. To warm us up for the year, let's do a quick review of some noteworthy research that's been happening.
The World's Smallest Fuel Cell
Chemical engineers at the University of Illinois at Urbana-Champaign have developed a fuel cell that measures a mere 3 mm by 3 mm by 1 mm. The first versions generated 0.7 V and 0.1 mA for 30 hours before the fuel (in this case, water) ran out although the latest designs provide around 1 mA at a similar voltage. The construction is particularly clever: A water reservoir sits atop a chamber holding metal hydride, the two separated by a membrane. Electrodes sit below the metal hydride. Water vapor passes through tiny holes in the membrane and reacts with the metal hydride to form hydrogen. The hydrogen then fills the chamber and pushes the membrane up, blocking the flow of water. As the hydrogen reacts with the electrodes to produce electricity, the supply is depleted and the membrane to relaxes downward again. Because the flow is controlled by surface tension, the fuel cell can operate in any orientation. However, according to New Scientist's article "World's smallest fuel cell promises greener gadgets", it may not be powerful enough to power portable gadgets.
A Prototype Cancer Scanner
Researchers at Stanford University have developed a prototype blood scanner ("Blood scanner detects even faint indicators of cancer") that can detect cancer-associated markers in blood within an hour and with greater sensitivity than current devices. The device builds on earlier research into a magnetic biodetection chip based on magnetic nanotechnology. The MagArray detector, a silicon chip, has 64 embedded sensors that monitor for changes in nearby magnetic fields.
"Capture antibodies"—antibodies that grab onto specific cancer-related proteins and hold onto them—are attached to the sensor. When a second batch of antibodies is added, they latch onto magnetic nanoparticles as well as to the biomarkers held captive by the sensors. When the MagArray sensor detects the magnetic field of the nanoparticles, it denotes the presence of the cancer markers.
Shan Wang, professor of materials science and of electrical engineering at Stanford University and senior author of the paper appearing in the Dec. 1 online edition of the Proceedings of the National Academy of Sciences, as quoted in the Stanford News Service article, "The earlier you can detect a cancer, the better chance you have to kill it," he said. "This could be especially helpful for lung cancer, ovarian cancer and pancreatic cancer, because those cancers are hidden in the body."
A Food Safety Sensor
A new biological sensor could be used to detect salmonella and other food-borne pathogens. The device was developed by Bosoon Park, an Agricultural Research Service engineer at the Quality and Safety Assessment Research Unit in Athens, GA, with cooperation from researchers at the University of Georgia. The biosensor includes fluorescent oganic dye particles that are attached to Salmonella antibodies. When exposed to Salmonella bacteria, these antibodies hook onto the bacteria and the dye fluoresces.
The biosensors that Park and his university colleagues developed include fluorescent organic dye particles attached to Salmonella antibodies. The antibodies hook onto Salmonella bacteria and the dye lights up like a beacon, making the bacteria easier to see. Considering how many food scares we had last year, a sensor that will make any present bacteria much easier to see is extremely welcome.
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