posted on 2021-05-20, 15:05authored byYupan Wu, Rajarshi Chattaraj, Yukun Ren, Hongyuan Jiang, Daeyeon Lee
Multiplex
separation of mixed biological samples is essential in
a considerable portion of biomedical research and clinical applications.
An automated and operator-independent process for the separation of
samples is highly sought after. There is a significant unmet need
for methods that can perform fractionation of small volumes of multicomponent
mixtures. Herein, we design an integrated chip that combines acoustic
and electric fields to enable efficient and label-free separation
of multiple different cells and particles under flow. To facilitate
the connection of multiple sorting mechanisms in tandem, we investigate
the electroosmosis (EO)-induced deterministic lateral displacement
(DLD) separation in a combined pressure- and DC field-driven flow
and exploit the combination of the bipolar electrode (BPE) focusing
and surface acoustic wave (SAW) sorting modules. We successfully integrate
four sequential microfluidic modules for multitarget separation within
a single platform: (i) sorting particles and cells relying on the
size and surface charge by adjusting the flow rate and electric field
using a DLD array; (ii) alignment of cells or particles within a microfluidic
channel by a bipolar electrode; (iii) separation of particles based
on compressibility and density by the acoustic force; and (iv) separation
of viable and nonviable cells using dielectric properties via the
dielectrophoresis (DEP) force. As a proof of principle, we demonstrate
the sorting of multiple cell and particle types (polystyrene (PS)
particles, oil droplets, and viable and nonviable yeast cells) with
high efficiency. This integrated microfluidic platform combines multiple
functional components and, with its ability to noninvasively sort
multiple targeted cells in a label-free manner relying on different
properties, is compatible with high-definition imaging, showing great
potential in diverse diagnostic and analysis applications.