Modelling and experimental study on the influence of surface grooves on near-field acoustic levitation

Near-field acoustic levitation is a novel non-contact handling technology. Its key challenge is the limited load-carrying capacity. This study introduced a simple method, i.e., adding grooves on the reflector surface, to improve load-carrying capacity. The flexural vibration mode and frequency of radiator plate were calculated through finite element analysis and validated by an experiment to determine air film thickness between two objects. The theoretical analysis and experimental study both indicated that circumferential grooves increased levitation force, whereas radial grooves decreased this force. Load capacity with different groove parameters was also investigated. Result indicated that groove depth and groove number were the optimal parameters and exhibited superior effects on levitation force, whereas the effect of groove width was smaller.