Posts Tagged ‘Sensor’
According to the report from American Physicists Organization Net, researchers from University of California, San Diego have developed a miniature chemical sensor which can be used in the mobile phone. With the help of mobile phone and other wireless communication equipments, this sensor can detect out harmful gas in the air in the first time, and then automatically send out the information about the type and transmitting range of the gas.
The design principle of the chemical sensor is to integrate hundreds of independent miniature sensors on the silicon chip with nano-pores in it. These sensors can identify the molecule of specific toxic gas and make correspondent response to it. Michael Shiller, the professor of biology and chemistry in University of California, San Diego, explains that it is similar to the process about how the nose perceives smell. The researchers install a set of “sensory cells” on the sensor. These “sensory cells” can perceive the characteristics of various chemical substances. If there is some specific chemical substance, the sensor will be activated at once, and then our brain will be able to identify the type of this specific chemical substance.
Mr. Shiller points out that mobile phones are prevailing among people in the modern society. With this technology applying to the majority of mobile phones, if there is any accident caused by toxic gas leakage or chemical pollution, with the help of this sensor embedded in the mobile phone, people can get information about the location and damage degree of the accident in the first time.
The researchers say that at present, this chip is able to distinguish between methyl salicylate and methyl benzene, and in the future, it will be able to identify hundreds of harmful chemical compounds. And what to do next is to add the tests on carbon monoxide and methane to the sensor. When there is a fire accident, the fire site is always filled with smoke, in which the carbon monoxide is a great threat to the health of the firefighters. However, with the sensor installed on the antigas masks, the firefighters will be able to decide whether it is safe to pick off the masks and use spontaneous breathing. Such sensor can also be applied to coal mine. When the concentration of the explosive gas is accumulated to certain degree, the sensor will give warning to the miners promptly and tell them to evacuate to the safe place.
After the cooperation with a company in San Diego, Shiller research group has succeeded in developing the model of such sensor, and has made preliminary test on the sensor connected with mobile phone.
Check us out at www.tutorvista.com A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together in a defined spatial arrangement by chemical bonds. Chemical compounds can be compound molecules held together by covalent bonds, salts held together by ionic bonds, metallic compounds held together by metallic bonds, or complexes held together by coordinate covalent bonds. Substances such as pure chemical elements and elemental molecules consisting of multiple atoms of a single element (such as H2, S8, etc.) are not considered chemical compounds. Elements form compounds to become more stable. They become stable when they have the maximum number of possible electrons in their outermost energy level, which is normally two or eight valence electrons. This is the reason that noble gases do not frequently react: they already possess eight valence electrons (the exception being helium, which requires only two valence electrons to achieve stability).