Magnetostrictive Microcantilever as an Advanced Transducer for Biosensors

The magnetostrictive microcantilever (MSMC) as a high-performance transducerwas introduced for the development of biosensors. The principle and characterization ofMSMC are presented. The MSMC is wireless and can be easily actuated and sensed usingmagnetic field/signal. More importantly, the MSMC exhibits a high Q value and works well inliquid. The resonance behavior of MSMC is characterized in air at different pressures and indifferent liquids, respectively. It is found that the Q value of the MSMC in water reaches about40. Although the density and viscosity of the surrounding media affect the resonancefrequency and the Q value of MSMC, the density has a stronger influence on the resonancefrequency and the viscosity has a stronger influence on the Q value, which result in that, forMSMC in air at pressure of less than 100 Pa, the resonance frequency of MSMC is almostindependent of the pressure, while the Q value increases with decreasing pressure. MSMCarray was developed and characterized. It is experimentally demonstrated that thecharacterization of an MSMC array is as simple as the characterization of a single MSMC. Afilamentous phage against Salmonella typhimurium was utilized as bio-recognition unit todevelop an MSMC based biosensor. The detection of S. typhimurium in water demonstratedthat the MSMC works well in liquid.