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Fluid mixing is commonly involved in various chemical and biological processes.However,it becomes a challenging task in miniaturized fluidic devices/systems due to increased viscous effects.[1,2] In our previous studies,flow induced vibration (FIV) is proposed for fluid mixing enhancement.[3,4] Here,we will report our recent progress in relevant studies.Through integration of elastic components into microfluidic devices,FIV can be produced due to enhanced hydro/aero-elasticity effects.This has been applied for design of micromixers.One is the oscillator-mixer that converts steady laminar flow to high-frequency oscillatory flow.In the previous design,[3] silicone rubber is used as the vibrating component which limits its applications regarding the chemical resistance and applicable fluid viscosity.In the new design (see Fig.1(a)),a more robust spring-metal (a copper/beryllium alloy) diaphragm is used which significantly improves its performance.As illustrated in Fig.2,the maximum applicable viscosity is improved from around 6 cP to above 60 cP.The device lifespan is also increased.Another example is the aeroelasticity-based fluidic agitator.[4] In this device (see Fig.1(b)),the vibration of an elastic diaphragm is induced by an external air flow,and it works as a micro-agitator to improve fluid mixing.The design is very effective,and as shown in Fig.3 rapid mixing can be achieved at viscosities up to 1000 cP.Relevant testing also shows that the design may be used for microparticles manipulation and flow pattern control.Different with conventional active micromixers,the current design makes use of flow induced spontaneous vibration.And hence the reliance on external controllers is greatly reduced,leading to simplified device structure and reduced fabrication cost.