Rapid construct superhydrophobic microcracks on the open-surface platform for droplet manipulations

Wan-Hsuan Lin; Chien-Wei Chen; Sheng-Hang Wang; Bor-Ran Li

doi:10.1038/s41598-021-94484-y

Rapid construct superhydrophobic microcracks on the open-surface platform for droplet manipulations

Sci Rep. 2021 Jul 21;11(1):14915. doi: 10.1038/s41598-021-94484-y.

Authors

Wan-Hsuan Lin¹, Chien-Wei Chen^{2

3}, Sheng-Hang Wang², Bor-Ran Li^{4

5

6}

Affiliations

¹ Institute of Biomedical Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, 1001 Ta-Hseh Rd., Hsinchu, Taiwan.
² Department of Electrical and Computer Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan.
³ Taiwan Instrument Research Institute, National Applied Research Laboratories, Hsinchu, Taiwan.
⁴ Institute of Biomedical Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, 1001 Ta-Hseh Rd., Hsinchu, Taiwan. liborran@nycu.edu.tw.
⁵ Department of Electrical and Computer Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan. liborran@nycu.edu.tw.
⁶ Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu, Taiwan. liborran@nycu.edu.tw.

Abstract

Droplet-based transport driven by surface tension has been explored as an automated pumping source for several biomedical applications. This paper presented a simple and fast superhydrophobic modify and patterning approach to fabricate various open-surface platforms to manipulate droplets to achieve transport, mixing, concentration, and rebounding control. Several commercial reagents were tested in our approach, and the Glaco reagent was selected to create a superhydrophobic layer; laser cutters are utilized to scan on these superhydrophobic surface to create gradient hydrophilic micro-patterns. Implementing back-and-forth vibrations on the predetermined parallel patterns, droplets can be transported and mixed successfully. Colorimetry of horseradish peroxidase (HRP) mixing with substrates also reduced the reaction time by more than 5-times with the help of superhydrophobic patterned chips. Besides, patterned superhydrophobic chips can significantly improve the sensitivity of colorimetric glucose-sensing by more than 10 times. Moreover, all bioassays were distributed homogeneously within the region of hydrophilic micropatterns without the coffee-ring effect. In addition, to discuss further applications of the surface wettability, the way of controlling the droplet impacting and rebounding phenomenon was also demonstrated. This work reports a rapid approach to modify and patterning superhydrophobic films to perform droplet-based manipulations with a lower technical barrier, higher efficiency, and easier operation. It holds the potential to broaden the applications of open microfluidics in the future.

Publication types

Research Support, Non-U.S. Gov't