The research objective of this Faculty Early Career Development (CAREER) Program project is to enable the implementation of self-powered sensing systems based on ionomeric materials. Creation of a hydrokinetic renewable energy device based on ionic polymer energy harvesting is proposed as a means to catalyze meaningful societal and educational shifts in the area of sustainability. While ionic polymer sensors demonstrate superior performance, there are currently no engineering models that capture the physics of selective ionic conduction in sensing. Among the consequences of this intellectual gap is a perceived trade off between sensitivity and mechanical integrity.
The project research offers a dual-physics hypothesis for the observed sensing response; validation of the hypothesis will enable a synthesis feedback loop resulting in mechanically robust ionic polymer sensors. The educational program addresses the need for sustainability education and technology development. Ionic polymer electromechanical sensing and harvesting will be used to create a novel hydrokinetic energy harvest device. This concept will be used to inspire curiosity and learning in both university and public sustainability education programs. The university component includes creation of a new certificate program; the public education component includes collaboration with leaders and citizens of Vandergrift, Pennsylvania in that town's transformation into an eco-municipality.
Intellectual Merit: Over the length of the program the goal of research was to theoretically study the interrelation between ionic polymer mechanical integrity and sensitivity. The heart of the program lies in the hypothesis that streaming potential is the physical mechanism responsible for sensing. The early stages of the program engaged in developing multiscale models to explore the mechanical integrity and streaming potential hypothesis (a function of selective ionic conduction ), respectively; the subsequent experimental studies and maturation of the modeling methodology have enabled hypothesis validation. Theory overlaid with experiment for IPT sensing modes of bending, shear, and compression have shown strong agreement, even in the absence of empirical fitting. In addition, the studies explored the implications of conductive particulate loading the electrode:ionomer interface region. Both theory and experiment suggest that optimum particulate loading, for the case of Ruthenium Dioxide and and ionic liquid as the IPT diluent, is in the vicinity of 40 vol%, irrespective of IPT deformation mode. Broader Impact: With the intent of simultaneously inspiring curiosity and creating undergraduate research opportunities, IPTs were explored for use by undergraduate researchers as candidates for hydrokinetic harvesters. The approach was successful in both regards; in addition to the specific undergraduate research opportunities, the program served as a catalyst to successfully launching a new Engineering for Humanity certficiate program, as well as fostering significant education-outreach programs for the student chapter of Engineers for a Sustainble World. During the approval process the Provost's committee requested that the certficate be made available to the entire university community, expanding impact opportunity from ~2100 (undergraduate engineering students) to ~34,000 (entire undergraduate population). In addition, the education outreach programs resulted in student led proposals and formation of programs reaching into the broader Pittsburgh region.
