EAGER: Polyelectrolyte Devices Based on Ion Current

Florida State University, Tallahassee FL

Investigators

Abstract

TECHNICAL SUMMARY A family of circuit components made from charged polymers and relying on ion current, instead of electron current, is proposed. Key materials will be based on polyelectrolyte complexes, prepared by mixing oppositely charged polymers, which form a rugged phase of amorphous, soft matter. This project involves both synthesis and characterization of polymers and polymer nanocomposites. The following components are to be made in this new paradigm: resistor, capacitor, transistor, memory. Each of these components relies on creative control of ion permeability through ultrathin films of these polyelectrolyte complexes. The resistors are designed to be controlled by an external potential. Capacitors rely on electrochemical storage or release of charge. Memory events will be created by quasipermanent modification of ion permeability. Transistors are designed to be directly "gated" by biomacromolecules in solution. In a closely coupled small angle neutron scattering study (SANS), the conformation of polymer components that make up the complex will be determined, using deuterated polyelectrolytes and contrast matching of the background. NON-TECHNICAL SUMMARY Circuits that use current of ions instead of electrons will be developed using charged polymers. Just as a lump of amorphous silicon can be transformed into an electronic circuit of the type on which our civilization is based, so too can a blob of amorphous charged polymer be shaped into useful devices. These ion current devices will reproduce the behavior of familiar circuit elements, such as the resistor, diode, capacitor, transistor and memory. The significance of using ion-based devices is that they are more easily integrated with natural systems, such as cells, which rely exclusively on ion currents. Thus, the proposed research will help us to interface the living world to the electronic environment. The project will exploit the unique ability of some polymers, many of which are used widely in society for other purposes, to conduct ion charge at room temperature. During the course of the work, undergraduate and graduate students will be required to think and operate beyond the usual definitions and materials for electronic circuits. They will also use state-of-the art facilities at Oak Ridge National Laboratory to study their novel materials. Built into the project is a research opportunity for an underrepresented minority student from Albany State University.