Patent ID: 7398671
Filing Date: 2008-07-15
Classification: G01N

Abstract:
1. A micromechanical sensor element for recording the bonding of molecules to the micromechanical sensor element, comprising: a substrate; at least one electrical terminal; an oscillatable element applied to the substrate, wherein the oscillatable element is secured to the substrate at least along a closed periphery and is coupled to a first of the at least one electrical terminal in such a manner that an electrical variable which characterizes the oscillation behavior of the oscillatable element is provided at the first of the at least one electrical terminal, wherein the oscillatable element comprises an oscillatable membrane, which is applied to the substrate in such a manner that a cavity is formed between the oscillatable membrane and the substrate, so that the membrane can be deflected into the cavity, wherein the oscillatable membrane is coupled to the first of the at least one electrical terminal, wherein at least one spacer element is provided between the substrate and the oscillatable membrane, and wherein the cavity is filled with piezoelectric material; a molecule coupling layer, which is oriented in such a manner that molecules can bond to the molecule coupling layer; the molecule coupling layer being coupled to the oscillatable element in such a manner that bonding of molecules to the molecule coupling layer can cause a change in the resonant frequency of the oscillatable element; and an electric circuit for determining the oscillation behavior of the oscillatable element, wherein the electric circuit is coupled to the oscillatable element via at least the first of the at least one electrical terminal, and wherein the electric circuit comprises means for generating an actuation signal with a predetermined frequency, by means of which actuation signal the oscillatable element is excited into oscillation; a feedback mechanism that feeds a signal based on an output of the oscillatable element back into the oscillatable element; and means for detecting and/or evaluating the change in the resonant frequency of the oscillatable element caused by the bonding of molecules to the molecule coupling layer, and wherein the electric circuit is integrated in the substrate or applied to the substrate of the micromechanical sensor element.