摘要 |
<p>The present invention relates to a sensor comprising least one sensor unit e.g. a cantilever. The sensor unit comprises a capture surface area and a piezoresistive detection system, for direct detection of stress change of the sensor unit when applying an electrical field over the piezoresistive element. The piezoresistive element has a longitudinal direction in the current direction and a transverse direction perpendicular there to. The longitudinal direction and the transverse direction each has a stress composant and a current composant. The piezoresistive element is of an anisotropic material, and is arranged so that the numerically value of the sum of the longitudinal piezoresistive coefficient pi1 and the transverse piezoresistive coefficient pit along at least 25% of the length, of the piezoresistive element is at least 10<-10> Pa<-1>x P, such as 2x10<-10>Pa<-1> x P. such as 3x10<-10>Pa<-1> x P, such as 4 x 10<-10>Pa<-1> x P, wherein P is the piezoresistance factor, and wherein the piezoresistive coefficients pi1 and pit are determined as composants in the coordinate system used to determine the longitudinal direction.</p> |