title: Active droplet sorting in microfluidics: a review.
abstract: The ability to manipulate and sort droplets is a fundamental issue in droplet-based microfluidics. Various lab-on-a-chip applications can only be realized if droplets are systematically categorized and sorted. These micron-sized droplets act as ideal reactors which compartmentalize different biological and chemical reagents. Array processing of these droplets hinges on the competence of the sorting and integration into the fluidic system. Recent technological advances only allow droplets to be actively sorted at the rate of kilohertz or less. In this review, we present state-of-the-art technologies which are implemented to efficiently sort droplets. We classify the concepts according to the type of energy implemented into the system. We also discuss various key issues and provide insights into various systems.
authors.affiliation: School of Aeronautics, Northwestern Polytechnical University, 127 West Youyi Rd., Xi'an, Shaanxi, China.
authors.forename: Heng-Dong
authors.initials: HD
authors.lastname: Xi
authors.affiliation: School of Aeronautics, Northwestern Polytechnical University, 127 West Youyi Rd., Xi'an, Shaanxi, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zheng
authors.affiliation: School of Aeronautics, Northwestern Polytechnical University, 127 West Youyi Rd., Xi'an, Shaanxi, China and Queensland Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road, Brisbane, QLD 4111, Australia. sayhwa.tan@griffith.edu.au.
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.affiliation: Depto. de Ingeniería Aeroespacial y Mecánica de Fluidos, Universidad de Sevilla, E-41092 Sevilla, Spain.
authors.forename: Alfonso M
authors.initials: AM
authors.lastname: Gañán-Calvo
authors.affiliation: Pillar of Engineering Product Development, Singapore University of Technology and Design, Singapore.
authors.forename: Ye
authors.initials: Y
authors.lastname: Ai
authors.affiliation: Department of Mechanical Engineering, National Central University, No. 300, Zhongda Rd, Taoyuan, Taiwan.
authors.forename: Chia-Wen
authors.initials: CW
authors.lastname: Tsao
authors.affiliation: School of Information and Communication Technology, Griffith University, Nathan, QLD 4111, Australia.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhou
authors.affiliation: School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Weihua
authors.identifier: 0000-0002-6190-8421
authors.initials: W
authors.lastname: Li
authors.affiliation: Biodynamic Optical Imaging Center, Peking University, Beijing 100871, China.
authors.forename: Yanyi
authors.identifier: 0000-0002-7297-1266
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Queensland Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road, Brisbane, QLD 4111, Australia. sayhwa.tan@griffith.edu.au.
authors.forename: Nam-Trung
authors.identifier: 0000-0003-3626-5361
authors.initials: NT
authors.lastname: Nguyen
authors.affiliation: Queensland Micro- and Nanotechnology Centre, Griffith University, 170 Kessels Road, Brisbane, QLD 4111, Australia. sayhwa.tan@griffith.edu.au.
authors.forename: Say Hwa
authors.identifier: 0000-0002-9764-7868
authors.initials: SH
authors.lastname: Tan