Reporter: Ming-Yen Chen(陳名彥) HIGH FREQUENCY SURFACE ACOUSTIC WAVE ATOMIZER J. Ju, Y. Yamagata, T. Higuchi, K. Inoue and H. Ohmori Graduate School of Engineering, The University of Tokyo. Tranducers07 Reporter: Ming-Yen Chen(陳名彥) Adviser :Cheng-Hsien Liu(劉承賢 )

outline Introduction Fabrication & Experimental Setup Experimental Results Conclusions & Discussion

Introduction -1 SAV-ED Surface Acoustic Wave Atomizer (electrostatic deposition) Surface Acoustic Wave Atomizer IDT LDA (Laser Doppler Anemometry)

Introduction -2 history of SAW atomizer 1927 Wood and Loomis ultrasonic atomization Relationship between drop size and exciteation frequency 1961 Lang Ultrasonic vibrator Measure the drop size : 10~800kHz 1995 Kurosawa SAW atomizer 10MHz , drop size : 5 – 60 um

Introduction -3 What is SAW? 1885 British physicist, mathematician Rayleigh Longitudinal wave + Shear wave = Rayleigh wave

Fabrication SAW atomizer

Experimental Setup -1 SAW-ED 5kV 12cm Test sample: Bovine serum albumin (BSA protein), 0.5 mg/ml, 100ul

Experimental Setup -2 LDA Laser 5mm

Experimental Results -1 SAW-ED Method (п/6) D03xC = (п/6) Dd3xρ Relationship between atomized droplet sizes and particle diameter: Size distribution of deposited particles and estimated droplet diameter using SAW-ED method, 0.5 mg/ml BSA, 50 MHz, 30 W, continues driving Droplet diameter range: 4.5 – 21 um

Experimental Results -2 LDA Measurement Size distribution of atomized droplets using LDA method, 50 MHz, 30 W, continues driving

Conclusions & Discussion 1 Compare SAW-ED & LDA

Conclusions & Discussion 2 Compare 50MHz & 10MHz range: 5 -60 um The droplet range is narrower than 10MHz

Conclusions & Discussion 3 thermal energy & kinetic energy In high frequency vibration, energy may be transferred into thermal energy due to internal damping. With thernal energy ,droplet will evaporation, not atomized by vibration. But, deposition of dry BSA particles indicates that liquid is atomized by kinetic energy.

Reference [1] W. R. Wood, A. L. Loomis, “The Physical and Biological Effects of High Frequency Sound Wave of Great Intensity”, Philos. Mag., pp.417-437, Sep., 1927 [2] R. J. Rang, “Ultrasonic Atomization of Liquids”, J.Acoust. Soc. Am., Vol. 34, No. 1, pp.6-8, Mar., 1961 [3] M. Kurosawa, T. Watanabe, A. Hutami, T. Higuchi, “Surface Acoustic Wave atomizer”,Sensors and Actuators A 50, pp. 69-74, 1995 [4] J. W. Kim, Y. Yamagata, M. Takasaki, B. H. Lee, H. Ohmori, T. Higuchi, “A device for fabricating protein chips by using a surface acoustic wave atomizer and electrostatic deposition”, Sensors and Actuators B 107, pp 535-545, 2005 [5] “Atomization Technology”, Institute for Liquid Atomization and Spray Systems-Japan, ISBN 4-627-67171-7, 2001 (in Japanese)

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