Breakthrough discovery enables nanoscale manipulation of the piezoelectric effect.
The generation of an electric field by the compression and expansion of solid materials is known as the piezoelectric effect, and it has a wide range of applications ranging from everyday items such as watches, motion sensors and precise positioning systems. Researchers at McGill University's Department of Chemistry have now discovered how to control this effect in nanoscale semiconductors called "quantum dots," enabling the development of incredibly tiny new products.
Although the word "quantum" is used in everyday language to connote something very large, it actually means the smallest amount by which certain physical quantities can change. A quantum dot has a diameter of only 10 to 50 atoms, or less than 10 nanometres. By comparison, the diameter of the DNA double-helix is 2 nanometres. The McGill researchers have discovered a way to make individual charges reside on the surface of the dot, which produces a large electric field within the dot.
"For example, the vibrations of a material can be analyzed to calculate the pressure of the solvent they are in. With further development and research, maybe we could measure blood pressure non-invasively by injecting the dots, shining a laser on them, and analyzing their vibration to determine the pressure." Tyagi notes that Cadium Selenide is a toxic metal, and so one of the hurdles to overcome with regard to this particular example would be finding a replacement material. ###
The research was published in Nano Letters and received funding from the Canada Foundation for Innovation, the Natural Sciences and Engineering Research Council of Canada, and the Fonds Québécois de la Recherche sur la Nature et les Technologies.
For more information: kambhampati-group.mcgill.ca
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