Patterning Hydrophobic Surfaces by Negative Microcontact Printing and Its Applications

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 14; no. 38; pp. e1802128 - n/a
• Main Authors: Wu, Han, Wu, Liang, Zhou, Xiaohu, Liu, Baishu, Zheng, Bo
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.09.2018
• Subjects: Arrays; Droplets; Fog; Hydrophobic surfaces; microlens array; Nanotechnology; Organic chemistry; Patterning; Polydimethylsiloxane; Printing; Silicone resins; single cell array; Surface energy; surface patterning; Thin films; single cell array; microlens array; surface patterning
• DOI: 10.1002/smll.201802128
• ISSN: 1613-6810; 1613-6829

Here, a negative microcontact printing method is developed to form hydrophilic polydopamine (PDA) patterns with micrometer resolution on hydrophobic including perfluorinated surfaces. In the process of the negative microcontact printing, a uniform PDA thin film is first formed on the hydrophobic surface. An activated polydimethylsiloxane (PDMS) stamp is then placed in contact with the PDA‐coated hydrophobic surface. Taking advantage of the difference in the surface energy between the hydrophobic surface and the stamp, PDA is removed from the contact area after the stamp release. As a result, a PDA pattern complementary to the stamp is obtained on the hydrophobic surface. By using the negative microcontact printing, arrays of liquid droplets and single cells are reliably formed on perfluorinated surfaces. Microlens array with tunable focal length for imaging studies is further created based on the droplet array. The negative microcontact printing method is expected to be widely applicable in high‐throughput chemical and biological screening and analysis. Hydrophobic surfaces are patterned with hydrophilic molecules by negative microcontact printing. Complex patterns in micrometer resolution are created in a simple contact transfer approach. The fabricated hydrophilic arrays on the hydrophobic surface facilitate producing droplet arrays by discontinuous dewetting and creating single cell arrays by exploiting the different cell adhesion properties on the hydrophilic and hydrophobic surfaces.