Скачать или смотреть SJSU-JABIL Collaboration: Injection Molded Centrifugal Microfluidic Chip for Droplet Generation

By: Radman Ahmadi, Anh Thu Le, Sam Hart
Technical Advisor: M. Simon (SJSU), Q. Chu (Jabil), H. Ernst (Jabil)
Senior Project Instructor: Prof.Folarin Erogbogbo, Ph.D.

Lab on a chip (LoC) microfluidic systems allow for the partitioning of samples into nano-scale droplets for absolute quantification. These droplets act as microreactors, allowing for hundreds of independent reactions to occur in parallel. However, traditional LoC fabrication methods are not scalable and current nano-droplet systems are large and expensive. Here, we present a droplet generating chip prototype for use on a centrifugal platform. The prototype was injection molded and vacuum ultraviolet (VUV) bonded cyclic-olefin polymer (COP) chips. In order to validate Jabil Green Point’s injection molding capabilities, the surface properties and microchannel dimensions, in addition to droplet generation, were investigated. The microchannel dimensions were verified using an optical measuring machine and determined to fit well within the provided 10% tolerance. Contact angle measurements on VUV treated and untreated samples revealed a change from hydrophobic to hydrophilic properties when exposed to VUV irradiation. The hydrophilic microchannels had a marked effect on fluid flow and surfactant efficacy. The resulting droplet break-off occurred away from the drop-off, where the step emulsification was expected to occur. In addition, droplets had diameters larger than that of the reservoir depth--roughly 500 microns compared to 200 microns--indicating that droplets are not spherical and droplet formation is not driven by the step height. Droplet generation was successful but results were inconsistent. Jabil Green Point’s ability to fabricate injection molded COP microfluidic chip has been verified. However, the chosen bonding method altered surface properties critical to step emulsification.