Abstract
Miniaturized enzymatic biofuel cells (EBFCs) with high cell performance are promising candidates for powering next-generation implantable medical devices. Here, we report a closed-loop theoretical and experimental study on a micro EBFC system based on three-dimensional (3D) carbon micropillar arrays coated with reduced graphene oxide (rGO), carbon nanotubes (CNTs), and a biocatalyst composite. The fabrication process of this system combines the top–down carbon microelectromechanical systems (C-MEMS) technique to fabricate the 3D micropillar array platform and bottom–up electrophoretic deposition (EPD) to deposit the reduced rGO/CNTs/enzyme onto the electrode surface. The Michaelis–Menten constant KM of 2.1 mM for glucose oxidase (GOx) on the rGO/CNTs/GOx bioanode was obtained, which is close to the KM for free GOx. Theoretical modelling of the rGO/CNT-based EBFC system via finite element analysis was conducted to predict the cell performance and efficiency. The experimental results from the developed rGO/CNT-based EBFC showed a maximum power density of 196.04 µW cm−2 at 0.61 V, which is approximately twice the maximum power density obtained from the rGO-based EBFC. The experimental power density is noted to be 71.1% of the theoretical value.
Highlights
Driven by demographic factors such as shifting lifestyle choices, degenerative chronic diseases, and growing geriatric population, the market for implantable medical devices (IMDs) stood at $43.1 billion in 2011 and is expected to increase to $116.3 billion by the end of 20221
The 3D micropillar arrays were constructed by the carbon microelectromechanical systems (C-MEMS) technique[18,19,20], which involves a two-step photolithography process followed by a pyrolysis step
The microstructure of electrophoretic deposition (EPD) codeposited enzyme/nanomaterial composites onto carbon microelectromechanical systems (CMEMS)-based 3D micropillar arrays was investigated by scanning electron microscopy (SEM)
Summary
Driven by demographic factors such as shifting lifestyle choices, degenerative chronic diseases, and growing geriatric population, the market for implantable medical devices (IMDs) stood at $43.1 billion in 2011 and is expected to increase to $116.3 billion by the end of 20221. Enzymatic biofuel cells (EBFCs), a subclass of fuel cells that employ enzymes to convert biological energy into electricity, have been touted as a potential power source for IMDs with typical power requirements of micro- to milliwatts[2]. EBFCs offer competitive advantages over conventional power sources, including the utilization of renewable and nontoxic biocomponents, high reaction selectivity and activity of biocatalysts, abundance of biofuels, and physiological operating conditions (human body temperature and near neutral pH)[3]. Major milestones in the evolution of bioelectricity generation are illustrated, i.e., Galvani’s bioelectricity in 17914, water electrolysis in 18395, the initial half-cell using Escherichia coli in 19106, the first microbial biofuel cells in 1931 (later funded by the NASA space program)[7] and the first EBFC using cell-free enzyme in 19648. Research on EBFCs remained relatively unnoticed until Berezin et al.[11] made one of the most outstanding contributions by discovering direct electron
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
