Submerged Surface Acoustic Wave Propulsion System with SiO2/Al/LN Structure

An autonomous swimmer with surface acoustic wave (SAW) is proposed and evaluated. Because the higher frequency makes the scale down and keeps the power density simultaneously in ultrasonics, the microrobots via acoustic propulsion are suitable for the pipeline and endovascular environments. To optimize the propulsion force of SAW, a fully submerged type is investigated in this work. SiO
2
film is coated on the surface of IDT as an insulating layer. Because SAW is generated symmetrically in both directions, half of the wave power cannot be used as the propulsion force in water. The flow velocity is observed with PIV measurements at different submerged positions of IDT in water. IDT submergence leads to a higher acoustic driving force in water. SiO
2
film is coated on the surface of IDT as an insulating layer. The fully submerged type with SiO
2
Coating has better propulsion force in the same input power and is more suitable as a small-scale and high-power propulsion system.