Traveling Surface Acoustic Wave Induced Removal of NSB Proteins from the Acoustic Biosensor

One challenge of current biosensors is to remove non-specifically bound (NSB). Surface acoustic wave (SAW) technology, because of its non-contact and non-marker characteristics, becomes one of the hot research fields and shows great prospects. In this paper, SAW is used to remove NSB. Firstly, the effect of the cut of the piezoelectric material on the removal force is determined based on the dispersion equation of the acoustic wave and the properties of the piezoelectric material. Secondly, the effects of channel height, excitation voltage and fluid medium temperature on the removal process are verified through theoretical calculations. The results show that the SAW force, lift force and drag force induce by the SAW can effectively remove the NSB, among which, SAW force mainly removes the nonspecifically bound from sensor surface, while the lift force and drag force mainly prevent the re-deposition of the removed NSB. Finally, the optimal region where NSB can be removed effectively by SAW is determined by comparing the SAW force and van der Waals force. When the sensing region is located in the optimal region, not only can the NSB be effectively removed, but also the performance of the sensor is guaranteed.