Investigations Of The Droplet Motion Excited By Lamb Waves On A Horizontal Non-piezoelectric Substrate

Driving in rainy days is a kind of high accident rate working condition.When water droplets on the windshield and the rear view mirror are not cleaned in time,the driver’s sight is blurred,which caused the driver’s misjudged the vehicle’s distance and the driving trend of the rear car.The occurrence of traffic accidents poses a great threat to the property security of the country and people.In view of the reliability and quality of the existing windshield wipers,the paper puts forward the use of surface acoustic wave technology to remove the droplets on the surface of windshield and rear view mirror.In this paper,the motion equation of droplet is obtained by force analysis when the droplet is propelled by Lamb waves on the horizontal non-piezoelectric substrate.The variables affecting the movement of the droplet on the horizontal non-piezoelectric substrate are analyzed.According to the variable design experiment,the effect of the variable on the velocities of the droplet on the horizontal non-piezoelectric substrate is summed up by combining the experimental result with the motion equation of the droplet.Experimental studies of velocities of droplet propelled by Lamb waves have been conducted to investigate the effects of parameters such as the non-piezoelectric substrate,input power on the SPT(single phase transducer),and droplet volume.Under a certain input power on the SPT and droplet volume,the velocities of advancing and receding edges droplets on glass plate are much higher than those on mirror plate.Moreover,it has been shown that an appropriate plate,a high input power and a decreased droplet volume result in an increase in velocities of droplets.The input power on SPT has been identified as the main factor influencing the velocities of droplets.Although,the droplet velocities is not proportional to the droplet volume under a certain input power on the SPT and a certain substrate,it is obtained that velocities of 10 μl droplets is the fastest and velocities of 30 μl droplet the slowest in the measurement.In the experiment of that the droplet is propelled by Lamb waves on the horizontal non-piezoelectric substrate,it is found that the water droplet has obvious oscillation deformation,and the oscillation deformation in different groups of experiments is different.In order to investigate the variation rule of oscillation deformation in water droplet movement,this paper uses the same method as the research of droplet motion mechanism.In order to quantify the oscillation degree of water droplet movement,the eccentricities of droplet is used to represent the deformation degree of droplet.According to the influencing factors of the above design experiment,the experimental results are summed up influence the law of oscillation deformation in droplet motion.The experimental results show that:(1)Under a certain non-piezoelectric substrate and droplet volume,the higher the input power on the SPT,the greater the eccentricities of droplet.(2)Under a certain non-piezoelectric substrate and input power on the SPT,the higher the droplet volume is,the greater the eccentricities of the droplet.(3)Under a certain input power on the SPT and droplet volume,the eccentricities of the water droplet on the glass substrate is greater than that of the mirror substrateIn this this paper,velocities of droplet propelled by Lamb waves and oscillatory deformation of droplet motion are investigated by combining theory with experiment.The research methods and experimental results provided theoretical and experimental basis for the removal of droplets from glass and mirror surfaces,which made it possible for saw equipment to replace the traditional automobile wiper.It also provides a certain reference for the experiment of driving droplet motion on the non-piezoelectric substrate.