A novel method for simultaneous readout of static bending and multimode resonance-frequency of microcantilever-based biochemical sensors

We propose a novel method for simultaneous readout of static bending and multimode resonance-frequency of a microcantilever. The method, as opposed to the currently most common approach, requires no external excitation of microcantilever's vibrations. It utilizes intrinsic thermal Brownian noise of the microcantilever. It allows monitoring the frequencies of several flexural and torsional vibration modes simultaneously along with static bending and twisting in both gaseous and liquid environments. We have developed a complete measurement setup for investigating microcantilever-based sensors. The setup consists of a measurement head with optical detection system, a liquid cell with working volume of 100 μl, all homemade, and PC-based processing software. We report a successful application of proposed method and developed system to investigation of microcantilever-based sensors in gaseous and liquid environments, with achieved time and frequency (mass) resolution competitive to previously reported methods.