Biofuel Cells for Biomedical Applications: Colonizing the Animal Kingdom

Abstract

Interdisciplinary research has combined the efforts of many scientists and engineers to gain an understanding of biotic and abiotic electrochemical processes, materials properties, biomedical, and engineering approaches for the development of alternative power-generating and/or energy-harvesting devices, aiming to solve health-related issues and to improve the quality of human life. This review intends to recapitulate the principles of biofuel cell development and the progress over the years, thanks to the contribution of cross-disciplinary researchers that have combined knowledge and innovative ideas to the field. The emergence of biofuel cells, as a response to the demand of electrical power devices that can operate under physiological conditions, are reviewed. Implantable biofuel cells operating inside living organisms have been envisioned for over fifty years, but few reports of implanted devices have existed up until very recently. The very first report of an implanted biofuel cell (implanted in a grape) was published only in 2003 by Adam Heller and his coworkers. This work was a result of earlier scientific efforts of this group to "wire" enzymes to the electrode surface. The last couple of years have, however, seen a multitude of biofuel cells being implanted and operating in different living organisms, including mammals. Herein, the evolution of the biofuel concept, the understanding and employment of catalyst and biocatalyst processes to mimic biological processes, are explored. These potentially green technology biodevices are designed to be applied for biomedical applications to power nano- and microelectronic devices, drug delivery systems, biosensors, and many more.

High-power biofuel cell textiles from woven biscrolled carbon nanotube yarns

“…Here, these mediated electron transfer-based systems usually have very efficient electron transfer between the enzyme and the electrode surface leading to larger current output 22 . However, the use of mediators in implantable devices could potentially generate issues with toxicity by the leakage of osmium or carbon nanotubes 23 . Similarly, stability of the device over its operating lifetime requires proper immobilization of the mediator and enzymes within the BFC.…”

Biohydrogen for a New Generation of H2/O2 Biofuel Cells: A Sustainable Energy Perspective

“…The most common EBFC developed so far was based on glucose oxidation by a flavin-containing enzyme, glucose oxidase, and oxygen reduction by multicopper-containing enzymes (MCOs), laccase (LAC) or bilirubin oxidase (BOD). [25,26] Because they can operate under mild conditions of temperature and pH using physiological fluids, the target was in vivo applications. Increasing numbers of examples of the applicability of such devices implanted in animals have been reported in recent years, and a recent review of the latest developments in that domain has been published.…”

Transparent and flexible, nanostructured and mediatorless glucose/oxygen enzymatic fuel cells

“…First, EFCs can potentially be produced at low cost and have great possibilities for miniaturisation. Second, the products of EFC operation are usually less harmful to the body compared to the products of conventional FCs [5]. Finally, a direct electron transfer (DET) based approach can allow great simplification in the designed biodevice, excluding the need for membranes and toxic mediators [6].…”