Sub-ppm detection of vapors using piezoresistive microcantilever array sensors.
The performance of microfabricated piezoresistive cantilever array sensors has been evaluated using various vapors of volatile organic compounds including alkanes with different chain length from 5 (n-pentane) to 14 (n-tetradecane). We demonstrate that piezoresistive microcantilever array sensors have the selectivity of discriminating individual alkanes in a homologous series as well as common volatile organic compounds according to principal component analysis. We developed a new method to evaluate the sensitivity, taking advantage of the low vapor pressures of alkanes with longer chains, such as n-dodecane, n-tridecane and n-tetradecane, under saturated vapor conditions. This method reveals sub-ppm sensitivity and the cantilever response is found to follow the mass of evaporated analytes as calculated using a quantitative model based on the Langmuir evaporation model.
National Center of Competence for Research in Nanoscience (NCCR), Department of Physics, University of Basel, 4056 Basel, Switzerland. Genki.Yoshikawa@unibas.ch
Genki
G
Yoshikawa
Hans-Peter
HP
Lang
Terunobu
T
Akiyama
Laure
L
Aeschimann
Urs
U
Staufer
Peter
P
Vettiger
Masakazu
M
Aono
Toshio
T
Sakurai
Christoph
C
Gerber