Jun 18 2007
Microelectromechanical Systems (MEMS) have come into existence only in the last decade. Microcantilevers are the most simplified MEMS based devices. They are of significant interest as they have potential applications in every field of science ranging from physical and chemical sensing to biological disease diagnosis.
The major advantages of employing microcantilevers as sensing mechanisms over the conventional sensors include their high sensitivity, low cost, low analyte requirement, non-hazardous procedure with fewer processing steps, quick response time and low power requirement. Most important is the fact that an array of microcantilevers can be employed for the diagnosis of large numbers of analytes such as various disease biomarkers of a single disease in a single go thus providing tremendously high throughput analysis capabilities.
In this comprehensive review of microcantilevers for sensing applications published in the open access journal AZojono, The AZo Journal of Nanotechnology, Dr. Sandeep Kumar Vashist of the National Centre for Sensor Research at Dublin City University, covers topics such as how microcantilevers work, how they can be used as sensors, their mechanical properties, areas of application as well as a focussed section on the use of microcantilevers in disease detection, an area of enormous potential.
On a basic level, these flexible sensors, analogous to tiny diving boards work by measuring the change in deflection or vibrational frequency of the microcantilever. Their extreme sensitivity, in the order of part per billion or parts per trillion allows them to detect materials at trace levels. This in turn means that these microcantilver based MEMS systems could be viable alternatives to current analytical techniques such as high performance liquid chromatography (HPLC), thin layer chromatography (TLC), gas chromatography (GC), gas liquid chromatography (GLC) etc. which can be complicated to use, expensive to purchase and require expert technicians.
Micro and nanocantilever sensors can be used to detect such things as humidity, temperature, herbicides, metal ions, viscosity, missile condition, radiation, biotoxins and explosives with a minimum of fuss, expertise and cost. In the medical field they can detect diseases such as cancer, coronary heart disease and myoglobin as well as making significant contributions to genomics and DNA analysis and blood glucose.
MEMS and microcantilever technology hold the key to the next generation of highly sensitive sensors. With the development of the technology for nanocantilevers, sensors have achieved attogram sensitivity, which has until recently, had only been a dream for researchers. Further increases in sensitivity and accuracy will allow researchers the ability to numbers of molecules.
This review paper is available online at https://www.azonano.com/Details.asp?ArticleID=1927