Gravity-induced drainage is one of the main destabilizing mechanisms for soap bubbles and foams.Here we show that solely through acoustic levitation without introducing any chemical stabilizers,liquid drainage in the ...Gravity-induced drainage is one of the main destabilizing mechanisms for soap bubbles and foams.Here we show that solely through acoustic levitation without introducing any chemical stabilizers,liquid drainage in the bubble film can be completely inhibited,therefore leading to a significant enhancement of bubble lifetime by more than two orders of magnitude and enabling the bubble to survive puncturing by a needle.Based on sound simulation and force analysis,it has been found that acoustic radiation force,exerted on both the inner and outer surfaces of the levitated bubble,acts in opposite directions,thus providing a squeezing effect to the bubble film.The hydrostatic pressure that induces drainage has been balanced by the acoustic radiation pressure exerted on both sides of the film,which is at the origin of the sound stabilization mechanism.This study provides new insights into the interplay between sound and soap bubbles or films,thus stimulating a wide range of fundamental research concerning bubble films and expanding their applications in bio/chemical reactors.展开更多
Acoustic levitation has developed into a popular but elegant tool for the study of drops as well as soft matter due to its exceptional levitation capabilities to a variety of liquid samples.The acoustically levitated ...Acoustic levitation has developed into a popular but elegant tool for the study of drops as well as soft matter due to its exceptional levitation capabilities to a variety of liquid samples.The acoustically levitated drops offer opportunities for the investigation of a wide range of fundamental issues related to liquid drops.In this review,the unique physics/chemical processes involved in acoustically levitated drops are dealt with.We first introduce the dynamics of the acoustically levitated drops,including drop oscillation,coalescence,and the associated capillary phenomena.The bubble formation and stability are also discussed.Depending on the inhibition of solid surfaces and the nonlinear effects of ultrasound,the self‐assembly of colloidal particles at the air–liquid interface as well as granular matter in air is reviewed.In particular,the exploration of biological drops by using acoustic levitation is also highlighted.In the end,the concept of acoustic‐levitation‐fluidics and possible potential topics are proposed.展开更多
基金the National Natural Science Foundation of China(Grant Nos.12272314,11972303)the Opening Fund of the State Key Laboratory of Nonlinear Mechanics for supporting this research financially.
文摘Gravity-induced drainage is one of the main destabilizing mechanisms for soap bubbles and foams.Here we show that solely through acoustic levitation without introducing any chemical stabilizers,liquid drainage in the bubble film can be completely inhibited,therefore leading to a significant enhancement of bubble lifetime by more than two orders of magnitude and enabling the bubble to survive puncturing by a needle.Based on sound simulation and force analysis,it has been found that acoustic radiation force,exerted on both the inner and outer surfaces of the levitated bubble,acts in opposite directions,thus providing a squeezing effect to the bubble film.The hydrostatic pressure that induces drainage has been balanced by the acoustic radiation pressure exerted on both sides of the film,which is at the origin of the sound stabilization mechanism.This study provides new insights into the interplay between sound and soap bubbles or films,thus stimulating a wide range of fundamental research concerning bubble films and expanding their applications in bio/chemical reactors.
基金National Nature Science Foundation of China,Grant/Award Numbers:11972303,12272314,U1904214。
文摘Acoustic levitation has developed into a popular but elegant tool for the study of drops as well as soft matter due to its exceptional levitation capabilities to a variety of liquid samples.The acoustically levitated drops offer opportunities for the investigation of a wide range of fundamental issues related to liquid drops.In this review,the unique physics/chemical processes involved in acoustically levitated drops are dealt with.We first introduce the dynamics of the acoustically levitated drops,including drop oscillation,coalescence,and the associated capillary phenomena.The bubble formation and stability are also discussed.Depending on the inhibition of solid surfaces and the nonlinear effects of ultrasound,the self‐assembly of colloidal particles at the air–liquid interface as well as granular matter in air is reviewed.In particular,the exploration of biological drops by using acoustic levitation is also highlighted.In the end,the concept of acoustic‐levitation‐fluidics and possible potential topics are proposed.
