UBC Theses and Dissertations
UBC Theses and Dissertations
A systematic perspective on conductive polymer blends using an integrated microfluidic-assisted microprinting system for combinatorial thin film library preparation Roy, Anindya Lal
This dissertation demonstrates the development of a novel printing platform with integrated mixing and dispensing capabilities for patterning compositionally graded thin film sample libraries of fluid material blends. The modular nature of the combinatorial print head enables the reusability of the mixing and dispensing modules while the elastomeric base structure may be replaced as desired due to its ease of handling and integration. Such a combinatorial print head is shown to consume smaller functional material volumes along with faster fabrication of thin films using such materials. The key advantage of these print heads is their ability to rapidly homogenize multiple fluid inputs which results in highly efficient multi-material thin film prototyping. An economical fabrication process for the disposable elastomeric base structure through a simple casting process using 3D printed molds is utilized. The requisite combinatorial functions of fluid proportioning and mixing are validated through extensive direct and indirect characterization. A sample preparation methodology is proposed and the combinatorial printing platform is assembled to validate operational performance electronic solution processable polymers that are typically used for fabricating sensor components. The intrinsically conductive electronic polymers are also tested for their microfluidic processability and inkjet printability. A statistical hypothesis testing framework is established for analyzing the characterization data which is then used for inferencing and validation. Case studies on multiple hypotheses involving the two types of intrinsically conductive polymers are performed which illustrates the utility of the combinatorial printing platform as a rapid thin film sample patterning tool with minimal material wastage. Analyses of the characterization data of such sample ensembles demonstrate the importance of the availability of a large number of functionally graded samples in the context of high throughput material screening. In addition, these tests are also used as an indirect performance evaluation of the combinatorial printing system when compared with benchmark processing of material blends. Conclusions regarding application-specific advantages and disadvantages of the two polymers are inferred in the context of standalone and temperature-dependent electrical conductivity performance as sensor materials and blending tests are used to determine the ideal operational niche of each material.
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Attribution-NonCommercial-NoDerivatives 4.0 International