Authors: B. Altunakar, J.L. Kokini
Affilation: University of Illinois at Urbana-Champaign, United States
Pages: 253 - 256
Keywords: films, lithography
Microfluidic components are widely used in the design of both bioanalytical and diagnostic microdevices. The miniaturized sample volumes together with modifications of the surface chemistry and localization of molecules within microfluid channels has opened many potential application areas in engineering and biomedical research fields. Photolithography is a commonly used technique for surface patterning. It requires passing light through a mask for patterning a surface with desired topography where a photosensitive resist is deposited on the substrate. Soft lithography which is an inexpensive and convenient technique for surface patterning has been used for microcontact printing, microfluid patterning, and micromolding. Soft lithography requires use of elastomeric polymers (e.g. polydimethylsiloxane) as a mold to transfer the patterns from the master plate on to substrates. Hereby, we will present the feasibility of use of biodegradable zein polymer as a substrate. Zein is a corn prolamine which can be processed to obtain water-insoluble, clear, edible film coatings for a wide range of food materials as well as encapsulation of nutraceuticals and drug components. Commercially it is produced from corn gluten meal which is a side product of bio-ethanol industry. Zein has excellent film forming ability due to formation of hydrophobic, hydrogen and disulfide bonds within zein chains. In this study, zein films were precisely nanofabricated with various features such as channels, wells, poles and grids. Master templates were created by using photolithography and soft lithography techniques were applied to create stamps from master templates. Polydimethysiloxane (PDMS) stamps with precisely controlled nano-scale patterns were used to transfer the patterns on to zein films. Scanning electron microscopy images revealed that pattern formation and transfer on to zein films were successful. The developed biocompatible patterned surfaces can further be functionalized to specifically bind to certain substrates such as proteins or cells. The application areas of this technology can be used as a tool in biomedical technologies to track specific molecules, to capture different types of biological substrate in design of lab-on-a-chip devices as well as building biodegradable and biocompatible scaffolds in tissue engineering.