Abstract
Micro-particle operations in many lab-on-a-chip devices require active-type techniques that are accompanied by complex fabrication and operation. The present study describes an alternative method using a passive microfluidic scheme that allows for simpler operation and, therefore, potentially less expensive devices. We present three practical micro-particle operations using our previously developed passive mechanical trap, the asymmetric trap, in a non-acoustic oscillatory flow field. First, we demonstrate size-based segregation of both binary and ternary micro-particle mixtures using size-dependent trap-particle interactions to induce different transport speeds for each particle type. The degree of segregation, yield, and purity of the binary segregations are 0.97 ± 0.02, 0.96 ± 0.06, and 0.95 ± 0.05, respectively. Next, we perform a solution exchange by displacing particles from one solution into another in a trap array. Lastly, we focus and split groups of micro-particles by exploiting the transport polarity of asymmetric traps. These operations can be implemented in any closed fluidic circuit containing asymmetric traps using non-acoustic oscillatory flow, and they open new opportunities to flexibly control micro-particles in integrated lab-on-a-chip platforms with minimal external equipment.
Highlights
Microfluidic applications of micro-particles require precise particle operations including separation, sorting, focusing, and solution exchange[1,2,3,4,5,6,7,8]
When micro-particles interact with asymmetric traps in an oscillatory flow field, their behavior can be classified as one of five types, as described in our previous study: one-way particle transport, symmetric passage, symmetric capturing, trap skipping in zig-zag mode, and trap skipping in bump mode (Supplementary Note S1, Figs S1 and S2)[53]
One-way particle transport is driven by an oscillatory flow field across asymmetric traps
Summary
Microfluidic applications of micro-particles require precise particle operations including separation, sorting, focusing, and solution exchange[1,2,3,4,5,6,7,8]. A range of practical functions[30,31,32,33,34,35,36,37,38,39,40] and unprecedented applications such as rare cell isolation[41,42,43] and mechanical characterization of single cells[44,45,46,47,48] have been demonstrated in the format of continuous flow This type of flow limits the number of independently controllable fluids[49,50], allows for potential cross-contamination[51], and presents challenges in metering and aliquoting reagents. The size-dependency of the particle dynamics, transport polarity, and multiplexing capability can be combined to create diverse functions beyond the particle operations demonstrated in this report
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
