Detection of bacteria based on the thermomechanical noise of a nanomechanical resonator: origin of the response and detection limits.

We have measured the effect of bacteria adsorption on the resonant frequency of microcantilevers as a function of the adsorption position and vibration mode. The resonant frequencies were measured from the Brownian fluctuations of the cantilever tip. We found that the sign and amount of the resonant frequency change is determined by the position and extent of the adsorption on the cantilever with regard to the shape of the vibration mode.

Measurement of the Mass and Rigidity of Adsorbates on a Microcantilever Sensor.

When microcantilevers are used in the dynamic mode, the resonance shift uponmaterial adsorption depends on the position of the adsorbate along the microcantilever. Wehave previously described that the adsorbate stiffness needs to be considered in addition toits mass in order to correctly interpret the resonance shift. Here we describe a method thatallows obtaining the Young's modulus of the adsorbed bacteria derived from themeasurement of the frequency shift when adsorbates are placed close to the clampingregion.

Study of the origin of bending induced by bimetallic effect on microcantilever.

An analytical model for predicting the deflection and force of a bimaterialcantilever is presented. We introduce the clamping effect characterised by an axial loadupon temperature changes. This new approach predicts a non linear thermal dependence ofcantilever strain.