Rational Design of High Dielectric Constant and Low Loss Dipolar Glass Polymers with Enhanced Orientational Polarization

Case Western Reserve University, Cleveland OH

Investigators

Abstract

NON-TECHNICAL SUMMARY: Numerous applications have been found for flexible hybrid electronics, including human performance monitoring, wearable medical sensors, information storage, and soft robotics. An indispensable component for flexible electronics is the printable dielectric layer, which regulates the electric current in the semiconductor. In response to this demand, this project is aimed at the design and development of novel printable high-performance dielectric polymers. In this project, a polymer theoretician will use advanced computer simulation to design and predict the dielectric properties for these new materials. A polymer chemist will synthesize the designed dielectric polymers, whose various properties and performance will be characterized by a polymer physicist (who will also be coordinating the research). A close loop among theoretical prediction, chemical synthesis, and polymer characterization will be built in the project to accelerate the progress. If successful, not only will our knowledge on polymer dielectric phenomena be advanced, but also new printable dielectric materials could ensue for future flexible electronics and energy-related applications. In addition to its industrial relevance, this project will also provide a comprehensive platform for education and outreach on science, technology, engineering, and mathematics (STEM). The project is aimed to include undergraduates and high-school students in research and to enhance diversity. It will also benefit an undergraduate/graduate course on Advanced Polymer Engineering which will include electrical properties of polymers for practical applications. Students will be encouraged to present their findings at local and major national meetings. TECHNICAL SUMMARY: A high-performance printable gate dielectric is an important component for future flexible field-effect transistors (FETs). To enhance the performance, past research has focused on decreasing the thickness of the gate dielectric, e.g., via self-assembled monolayers. Although high capacitance density can be achieved using ultrathin dielectrics, manufacturability has been challenging due to the susceptibility of ultrathin films to intrinsic defects, such as pinholes and grain boundaries. To circumvent this manufacturing challenge, the dielectric constant of printable gate dielectrics has to be substantially increased while keeping the dielectric loss low. In addition, gate dielectrics should have good mechanical stability and good response to external fields in a wide range of frequencies. To realize reliable printable/flexible FETs, this project aims to design and develop novel high-dielectric-constant and low-loss dipolar glass polymers with intrinsic microporosity (DG-PIMs). First, theoretical analysis and computer simulation using mixed full atomistic and coarse-grained molecular dynamics will guide the design and synthesis of DG-PIMs. Post-modifications will be employed to convert conventional PIMs into novel DG polymers. Both structural and dielectric properties will be characterized, and computer simulation studies will be refined on the basis of the experimental results. Through this cycle of computer simulation, polymer synthesis, structure/property characterization, and feedback, enhanced orientational polarization in the proposed DG-PIMs will be fully explored and improved new materials produced.