Abstract
In this paper, we first report on direct-photolithography-based microfabrication of transparent superhydrophobic micropatterns using novel photodefinable nanocomposites, combining the nanomorphology and hydrophobicity of polytetrafluoroethylene (PTFE) nanoparticles and the photopatternability and transparency of an SU-8 photoresist using both direct-mixing and coating-immobilization methods. The direct mixture of PTFESU-8 nanocomposite can be reliably spin-coated and photopatterned onto transparent substrates (e.g., glass or polymers) with a minimal feature resolution of 50 μ\hbox{m}. The resulting nanocomposite film possesses a contact angle of water at 150, although its optical transparency is less than 30%. Furthermore, a modified coating-immobilization approach, employing spray coating and thermal immobilization of PTFE nanoparticles onto an SU-8 polymer matrix, significantly enhances superhydrophobicity, lithography resolution, as well as optical transparency. The highest optical transparency of 80% and a minimal feature resolution of 10 μhbox{m} have been achieved using the standard photolithography approach, while the contact angle of water above 165 enables extraordinary superhydrophobicity with low hysteresis. The novel PTFESU-8 nanocomposites provide a unique combination of superhydrophobicity, optical transparency, and photopatternability, along with excellent adaptability and simple processability, which offer great extension to rapidly evolving micronanoengineering applications.
Original language | English (US) |
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Article number | 5430872 |
Pages (from-to) | 246-253 |
Number of pages | 8 |
Journal | Journal of Microelectromechanical Systems |
Volume | 19 |
Issue number | 2 |
DOIs | |
State | Published - Apr 1 2010 |
Keywords
- Microfabrication
- Nanocomposite
- Nanoparticle
- Photolithography
- Polytetrafluoroethylene (PTFE)
- SU-8
- Superhydrophobicity
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Mechanical Engineering