posted on 2021-01-04, 07:48authored byGe Chen, Ziyi Dai, Shunbo Li, Yifeng Huang, Yi Xu, Juncong She, Bingpu Zhou
Droplet
manipulations are critical for applications ranging from
biochemical analysis, medical diagnosis to environmental controls.
Even though magnetic actuation has exhibited great potential, the
capability of high-speed, precise manipulation, and mixing improvement
covering a broad droplet volume has not yet been realized. Herein,
we demonstrated that the magnetic actuation could be conveniently
achieved via decorating the magnetically responsive film with microcilia.
Under magnetic field, the film can quickly response with localized
deformation, along with the microcilia to realize the surface superhydrophobicity
for droplet manipulation with velocity up to ∼173 mm/s covering
a broad volume of 2–100 μL. The robust system further
allows us to realize rapid and complete droplet mixing within ∼1.6
s. In addition, the microcilia decorated surface can preserve the
robust superhydrophobicity after various stability tests, for example,
normal pressing, chemical corrosion, and mechanical abrasion, exhibiting
the possibility toward the long-term and real applications. With the
multifunctional demonstrations such as obvious mixing improvement,
parallel manipulation, and serial dilution, we believe that the methodology
can open up a magnetic field-based avenue for future applications
in digital microfluidics, and biochemical assays, etc.