A dynamically deformable microfilter for selective separation of specific substances in microfluidics

Seitaro Kumamoto; Kenshiro Nakatake; Souichiro Fukuyama; Keiichiro Yasuda; Yusuke Kitamura; Masaaki Iwatsuki; Hideo Baba; Toshihiro Ihara; Yoshitaka Nakanishi; Yuta Nakashima

doi:10.1063/5.0025927

A dynamically deformable microfilter for selective separation of specific substances in microfluidics

Biomicrofluidics. 2020 Dec 24;14(6):064113. doi: 10.1063/5.0025927. eCollection 2020 Nov.

Authors

Seitaro Kumamoto, Kenshiro Nakatake¹, Souichiro Fukuyama¹, Keiichiro Yasuda², Yusuke Kitamura³, Masaaki Iwatsuki⁴, Hideo Baba⁴, Toshihiro Ihara³, Yoshitaka Nakanishi, Yuta Nakashima

Affiliations

¹ Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan.
² Ogic Technologies Co. Ltd., 2-9-9, Kamikumamoto, Nishi-ku, Kumamoto 860-0079, Japan.
³ Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan.
⁴ Faculty of Life Science, Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan.

Abstract

To study an environmental or biological solution, it is essential to separate its constituents. In this study, a 3D-deformable dynamic microfilter was developed to selectively separate the target substance from a solution. This microfilter is a fine metallic nickel structure fabricated using photolithography and electroplating techniques. It is gold-coated across its entire surface with multiple slits of 10-20 μm in width. Its two-dimensional shape is deformed into a three-dimensional shape when used for fluid separation due to hydrodynamic forces. By adjusting the pressure applied to the microfilter, the size of the gap created by deformation can be changed. To effectively isolate the target substance, the relationship between the solution flow rate and the extent of microfilter deformation was investigated. The filtration experiments demonstrated the microfilter's ability to isolate the target substance with elastic deformation without undergoing plastic deformation. Additionally, modification of the microfilter surface with nucleic acid aptamers resulted in the selective isolation of the target cell, which further demonstrates the potential application of microfilters in the isolation of specific components of heterogeneous solutions.