Device Structure Design And Principle Analysis For Concentrating The Micro/Nano Material

Piezoelectric transducer is one kind of actuators which relies the piezoelectric effect ofpiezoelectric materials to achieve mutual conversion between electric power and mechanical energy.Piezoelectric transducer is the main method in ultrasonic technology, which has great varieties,extensive application. For example it has broad scenarios in the manipulations of micro/nano material.The project research on the concentration of micro/nano material in a film of aqueous suspension on astationary substrate (not in vibration), which employs the acoustic streaming generated by anultrasonically vibrating needle parallel to and above the stationary substrate. The following are theprimary content:The related researches introducing present situation of micro/nano-scale material manipulationmethods with their advantages and disadvantages respectively by piezoelectric transducer isintroduced. We also introduce piezoelectric driving technology、research purpose、 study range andsignificance of this project.Through experimental measurement and theoretical analysis, we study the characteristic andprinciple of the concentration of micro/nano material. The needle vibrates in a flexural mode withhigh vibrating frequency. At this time there will be acoustic streaming around the location with largevibration amplitude. The acoustic streaming induces micro/nano material to aggregate discontinuouslyunder the needle on the substrate.The phenomenon of forming a continuous linear line is investigated. We move the needle backand forth along a linear trajectory, and now there will be a continuous linear line formed bymicro/nano material.We also study the reason generating the acoustic streaming. Through finite element softwareCOMSOL, we got the pattern of acoustic streaming around the anti-node of the needle, which is thesame with the experimental observations. Theoretical calculation results showed than the drivingforce on a saccharomycetes particle was estimated to have the order of magnitudes of.