title: Acoustofluidic control of bubble size in microfluidic flow-focusing configuration.
abstract: This paper reports a method to control the bubble size generated in a microfluidic flow-focusing configuration. With an ultrasonic transducer, we induce acoustic streaming using a forward moving, oscillating gas-liquid interface. The induced streaming substantially affects the formation process of gas bubbles. The oscillating interface acts as a pump that increases the gas flow rate significantly and forms a larger bubble. This method is applicable to a wide range of gas pressure from 30 to 90 kPa and flow rate from 380 to 2700 μL h(-1). The bubble size can be tuned repeatedly with the response time on the order of seconds. We believe that this method will enhance the capability of a microfluidic bubble generator to produce a tunable bubble size.
authors.affiliation: School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798. sayhwa.tan@gmail.com.
authors.forename: Zhuang Zhi
authors.initials: ZZ
authors.lastname: Chong
authors.forename: Shu Beng
authors.initials: SB
authors.lastname: Tor
authors.forename: Ngiap Hiang
authors.initials: NH
authors.lastname: Loh
authors.forename: Teck Neng
authors.initials: TN
authors.lastname: Wong
authors.forename: Alfonso M
authors.initials: AM
authors.lastname: Gañán-Calvo
authors.forename: Say Hwa
authors.initials: SH
authors.lastname: Tan
authors.forename: Nam-Trung
authors.initials: NT
authors.lastname: Nguyen