Accueil > Français > Événements > Séminaires > Séminaires Magnétisme et Supraconductivité > Archives 2008

Ultrasensitive Chemical Vapor Sensors based on VHF nanoelectromechanical (NEMS) Resonators

Edward Myers, Kavli Nanoscience Institute Caltech, USA

We have developed a sensor platform based on very high frequency (VHF) nanoelectromechanical (NEMS) resonators that provides real-time analyte mass detection with unprecedented sensitivity in ambient conditions, and at sizes and power levels that are orders of magnitude below those of traditional acoustic gas sensors such as surface acoustic wave (SAW) and flexural plate wave (FPW) devices. The sensors, consisting of piezoresistive cantilevers coated with chemically-sensitive films, are as small as 700 nm in length and have fundamental flexural resonance mode frequencies as high as 180 MHz. Using this technology, we have detected adsorbed analyte gas pulses as small as 1 attogram (1 ag = 10-18 g) in a 1 Hz bandwidth at atmospheric pressure and room temperature. Such mass sensitivity corresponds to sub-ppb (ppb = parts per billion) sensitivity to many gases of relevance. NEMS-based gas sensors may find use in a wide range of applications, from chemical/biological agent detection to environmental monitoring and medical diagnostics.