Toward Biodegradable Mg–Air Bioelectric Batteries Composed of Silk Fibroin–Polypyrrole Film

Abstract

Biodegradable active implantable devices can be used to diagnose and/or treat disease and eventually disappear without surgical removal. If an "external" energy source is required for effective operation then a biocompatible and biodegradable battery would be ideal. In this study, a partially biodegradable Mg-air bioelectric battery (biobattery) is demonstrated using a silk fibroin-polypyrrole (SF-PPy) film cathode coupled with bioresorbable Mg alloy anode in phosphate buffered saline (PBS) electrolyte. PPy is chemically coated onto one side of the silk substrate. SF-PPy film shows a conductivity of ≈1.1 S cm−1 and a mild catalytic activity toward oxygen reduction. It degrades in a concentrated buffered protease XIV solution, with a weight loss of 82% after 15 d. The assembled Mg-air biobattery exhibits a discharge capacity up to 3.79 mA h cm−2 at a current of 10 μA cm−2 at room temperature, offering a specific energy density of ≈4.70 mW h cm−2. This novel partially biodegradable battery provides another step along the route to biodegradable batteries. Abstract:Biodegradable active implantable devices can be used to diagnose and/or treat disease and eventually disappear without surgical removal. If an "external" energy source is required for effective operation then a biocompatible and biodegradable battery would be ideal. In this study, a partially biodegradable Mg-air bioelectric battery (bio-battery) was demonstrated using a silk fibroin-polypyrrole (SF-PPy) film cathode coupled with bioresorbable Mg alloy anode in phosphate buffered saline (PBS) electrolyte. Polypyrrole (PPy) is chemically coated onto one side of the silk substrate. SF-PPy film shows a conductivity of ~1.1 S cm -1 and a mild catalytic activity towards oxygen reduction. It degrades in a concentrated buffered 2 protease XIV solution, with a weight loss of 82% after 15 days. The assembled Mg-air biobattery exhibit a discharge capacity up to 3.79 mA h cm -2 at a current of 10 µA cm -2 at room temperature, offering a specific energy density of ∼4.70 mW h cm -2 . This novel partially biodegradable battery provides another step along the route to biodegradable batteries.

Morphology and ionic conductivity relationship in silk/cellulose biocomposites

“…These materials have been used to create scaffolds for tissue growth as well as capsules used for drug delivery systems . Creating implantable batteries using natural biomaterials has become significant in various medical applications . Having the ability to control the properties of these biomaterial‐based batteries, including morphological, thermal and mechanical properties, is essential in creating devices which are minimally harmful in the human body and are advantageous in the medical field.…”

Bioresorbable Materials on the Rise: From Electronic Components and Physical Sensors to In Vivo Monitoring Systems

“…No dissolution tests were performed on this battery. The same group next developed biodegradable batteries that used an AZ31 foil anode and either PPy‐ p TS or gold nanoparticles deposited on a silk fibroin substrate as cathode. In the latter work, silk fibroin−choline nitrate (SF‐[Ch][NO 3 ]) was used as polymer electrolyte .…”

Toward Promising Cathode Catalysts for Nonlithium Metal–Oxygen Batteries

“…Copyright 2016, Royal Society of Chemistry; d) discharge profile of the Mg–O 2 battery using the SF‐PPy catalyst at different current densities; e) weight changes of the SF‐PPy film and the SEM images of the film cultivated in buffered protease XIV solution before and after 15 days. Reproduced with permission . Copyright 2016, Wiley‐VCH…”