Bioinspired materials for powering next generation biomedical devices
Speaker
Young Jo Kim
University of New Hampshire.
Abstract
Biodegradable electronics presents an emerging paradigm in biomedical applications by exhibiting various advantages afforded by electronically active devices systems and obviating issues with chronic implants such as infection, inflammation, and costly surgical procedures. Devices designed for oral administration are especially advantageous because they can be deployed in non-invasive manner. Examples include ingestible event monitors, smart drug delivery system, and capsule cameras for endoscopy. Polymeric encapsulation and high-performance batteries have offered a feasible solution, however there remains various challenges regarding potentially toxic electrodes and hazardous electrolytes.
I would like to present the utility of naturally-derived biomaterials, eumelanin pigments as electrochemical energy storage devices for powering biomedical devices. Eumelanins are a broad class of redox active biopolymers that are composed of catechol-bearing redox active planar protomolecules. Eumelanins exhibit unique optoelectronic properties including efficient photon-phonon conversion, free radical scavenging, redox activity, and followed by reversible monovalent/divalent cation chelation. The utility of eumelanins as energy storage materials for aqueous Na+ batteries is advantageous because this can potentially use Na+ inside of the stomach fluid. When coupled with Na2Ti2(PO4)2 (NTP) anodes, initial full cell potentials
exhibit about 0.9 V and maximum capacity reaches 80 mAhg-1 with a stable potential of 0.5 V, whose performance is comparable to operate the electronic devices for about 10 hours with the current density of 0.05 Ag-1.
In addition, structure-property-processing relationships will be emphasized and prospective uses for these application-specific materials will be discussed. Molecular composition of eumelanin pigments is well understood, little has been known about the macromolecular topology that links monomers including dihydroxyindole (DHI) and dihydroxyindole-carboxylic acid (DHICA). Increased understanding of meso-scale protomolecules of eumelanin pigments could provide insight into the template-assisted self assembly during melanogenesis and the origin of bulk optoelectronic properties.