title: Automated long-term monitoring of parallel microfluidic operations applying a machine vision-assisted positioning method.
abstract: As microfluidics has been applied extensively in many cell and biochemical applications, monitoring the related processes is an important requirement. In this work, we design and fabricate a high-throughput microfluidic device which contains 32 microchambers to perform automated parallel microfluidic operations and monitoring on an automated stage of a microscope. Images are captured at multiple spots on the device during the operations for monitoring samples in microchambers in parallel; yet the device positions may vary at different time points throughout operations as the device moves back and forth on a motorized microscopic stage. Here, we report an image-based positioning strategy to realign the chamber position before every recording of microscopic image. We fabricate alignment marks at defined locations next to the chambers in the microfluidic device as reference positions. We also develop image processing algorithms to recognize the chamber positions in real-time, followed by realigning the chambers to their preset positions in the captured images. We perform experiments to validate and characterize the device functionality and the automated realignment operation. Together, this microfluidic realignment strategy can be a platform technology to achieve precise positioning of multiple chambers for general microfluidic applications requiring long-term parallel monitoring of cell and biochemical activities.
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Hon Ming
authors.initials: HM
authors.lastname: Yip
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: John C S
authors.initials: JC
authors.lastname: Li
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Kai
authors.identifier: 0000-0002-9090-8383
authors.initials: K
authors.lastname: Xie
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Xin
authors.initials: X
authors.lastname: Cui
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Agrim
authors.identifier: 0000-0001-5838-755X
authors.initials: A
authors.lastname: Prasad
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Qiannan
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Chi Chiu
authors.initials: CC
authors.lastname: Leung
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Raymond H W
authors.identifier: 0000-0002-5188-3830
authors.initials: RH
authors.lastname: Lam
mesh_terms: D000465:Algorithms; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D044085:Microfluidics / Q000295:instrumentation / Q000379:methods*