Systematic investigation of the benchtop surface wrinkling process by corona discharge†
Periodic micro/nanostructures with the characteristic dimensions at single or two length scales have manifested their strengths in providing contact cues to regulate cell alignment and motility, creating diffractive gratings for wavelength selection and pulse compression, and producing tailored surface wettability and adhesion. The currently used lithographic and surface wrinkling methods often require substantial use of special fabrication facilities and a cleanroom environment, and are accompanied by complicated fabrication processes. This paper systematically examines a facile benchtop wrinkling process to produce periodic micro/nanostructures and hierarchical topographies on elastomeric substrates in a general wet laboratory. Atmospheric electric discharge generated by a hand-held corona surface treater produces a rigid thin film atop an elastomeric foundation containing an initial tensile strain. Periodic sinusoidal wrinkled deformations with tailored wavelengths and amplitudes form spontaneously upon stress removal. This process is compatible with commercial tensile test machines and can create elastomeric micro/nanowrinkled structures within minutes. It can also be coupled with softlithography and/or photolithography to generate hierarchical wrinkled topographies with various degrees of anisotropy. This work provides a technical basis for versatile manufacturing of periodic and hierarchical wrinkled topographies at different length scales for various applications.