Title: Ion Locking by Electric Field Catalyzed Crosslinking Reactions in Solid Polymer Electrolytes

Abstract: Unpaired ions in proximity to conducting materials induce opposite image charges in the material that can impart unique functionality in electronic devices. For example, when ions in a solid polymer electrolyte (SPE) are driven to the channel interface of electric double layer transistors (EDLTs) by an applied gate potential (VG), the channel becomes doped to allow more charge carriers to transverse between the source and drain. When the channel material is ambipolar (i.e., capable of conducting electrons and holes), reversing the polarity of the VG reconfigures the channel doping to allow for the flow of the opposite charges. This mechanism has potential applications for hardware security if permanent doping can be achieved without a constantly applied VG. One potential approach to perform non-volatile doping is using the large electric fields (EFs) generated at the EDL (~V/nm) to catalyze reactions that lock ions at the SPE/channel interface. Aim 1 of the proposed work is to design and synthesize EF-sensitive SPEs that undergo crosslinking reactions to lock ions only when VG is above the threshold to induce reactivity. Non-volatile n-type doping has been demonstrated by crosslinking SPEs using the Menshutkin reaction. Additional mechanisms to be studied are Diels-Alder and azide-alkyne cycloadditions. The SPEs will be chemically characterized to provide evidence of crosslinking and elucidate the contributions to channel doping.

Another application of unpaired ions is for renewable energy generation, for example in wave energy converters (WECs). However, the factors preventing WEC technologies from entering commercial markets in the U.S. are energy conversion efficiency, technology scalability, and costs. Aim 2 reveals a new type of energy transducer designed to address these barriers called polar ionic nanogenerators (PINGs). These devices directly convert mechanical energy into electricity using a novel yet straightforward fabrication technique that permanently separates unpaired ions. Power output has been demonstrated in proof-of-concept prototypes using materials from Aim 1. Future work includes iterating the design to improve their performance. Aim 3 expands on the commercialization prospect of PINGs by evaluating their utility for recreational and commercial maritime applications through product market fit and techno-economic analysis. The results of Aims 2 and 3 will be used to determine if pursuing the commercialization of PINGs through entrepreneurship is a viable path forward.

Chair:

Dr. Susan Fullerton

Department of Chemical and Petroleum Engineering, University of Pittsburgh

Committee Members:

Dr. James McKone

Department of Chemical and Petroleum Engineering, University of Pittsburgh

 Dr. Lei Li

Department of Chemical and Petroleum Engineering, University of Pittsburgh

Dr. Jennifer Laaser

Department of Chemistry, University of Pittsburgh

Dr. Brandon Grainger

Department of Electrical and Computer Engineering, University of Pittsburgh