Nanotextured Shrink Wrap Superhydrophobic Surfaces by Argon Plasma Etching

Jolie M Nokes; Himanshu Sharma; Roger Tu; Monica Y Kim; Michael Chu; Ali Siddiqui; Michelle Khine

doi:10.3390/ma9030196

Nanotextured Shrink Wrap Superhydrophobic Surfaces by Argon Plasma Etching

Materials (Basel). 2016 Mar 14;9(3):196. doi: 10.3390/ma9030196.

Authors

Jolie M Nokes¹, Himanshu Sharma², Roger Tu³, Monica Y Kim⁴, Michael Chu⁵, Ali Siddiqui⁶, Michelle Khine^{7

8}

Affiliations

¹ Department of Biomedical Engineering, Samueli School of Engineering, University of California, Irvine; Irvine, CA 92697, USA. mclanej@uci.edu.
² Department of Chemical Engineering and Material Sciences, Samueli School of Engineering, University of California, Irvine; Irvine, CA 92697, USA. sharmah@uci.edu.
³ Department of Biology, Ayala School of Biological Sciences, University of California, Irvine; Irvine, CA 92697, USA. tur@uci.edu.
⁴ Department of Biomedical Engineering, Samueli School of Engineering, University of California, Irvine; Irvine, CA 92697, USA. monicayk@uci.edu.
⁵ Department of Biomedical Engineering, Samueli School of Engineering, University of California, Irvine; Irvine, CA 92697, USA. mchu8@uci.edu.
⁶ Department of Biomedical Engineering, Samueli School of Engineering, University of California, Irvine; Irvine, CA 92697, USA. siddiqa1@uci.edu.
⁷ Department of Biomedical Engineering, Samueli School of Engineering, University of California, Irvine; Irvine, CA 92697, USA. mkhine@uci.edu.
⁸ Department of Chemical Engineering and Material Sciences, Samueli School of Engineering, University of California, Irvine; Irvine, CA 92697, USA. mkhine@uci.edu.

Abstract

We present a rapid, simple, and scalable approach to achieve superhydrophobic (SH) substrates directly in commodity shrink wrap film utilizing Argon (Ar) plasma. Ar plasma treatment creates a stiff skin layer on the surface of the shrink film. When the film shrinks, the mismatch in stiffness between the stiff skin layer and bulk shrink film causes the formation of multiscale hierarchical wrinkles with nano-textured features. Scanning electron microscopy (SEM) images confirm the presence of these biomimetic structures. Contact angle (CA) and contact angle hysteresis (CAH) measurements, respectively, defined as values greater than 150° and less than 10°, verified the SH nature of the substrates. Furthermore, we demonstrate the ability to reliably pattern hydrophilic regions onto the SH substrates, allowing precise capture and detection of proteins in urine. Finally, we achieved self-driven microfluidics via patterning contrasting superhydrophilic microchannels on the SH Ar substrates to induce flow for biosensing.

Keywords: argon plasma treatment; bioinspired material; detection; fabrication; microfluidics; protein capture; shrink film; superhydrophobic; wicking.

Grants and funding

DP2 OD007283/OD/NIH HHS/United States