Implanted biofuel cells operating in vivo – methods, applications and perspectives – feature article

Abstract

This feature article is an overview of the recent research activity in the area of enzyme-based biofuel cells implanted and operating in vivo in living creatures (insects, mollusks, rats, rabbits, etc.). The electrical power extracted from these biological sources presents use for activating microelectronic devices for biomedical applications (e.g. pacemakers) or sensors/biosensors for environmental monitoring. The inequality of the voltage generated by the biofuel cell (which is thermodynamically limited by the redox potentials of the biomolecular fuel and oxygen) and the voltage demanded by the electronic devices requires special attention and can be resolved by specific interfacing with charge pumps and DC-DC converters. The paper focuses on the problems in the present technology as well as offers their potential solutions.Lastly, perspectives and future applications of the implanted biofuel cells are also discussed. Broader contextImplantable devices harvesting energy from biological sources and based on electrochemical, mechanical and other energy transducers are currently receiving a high amount of attention. The energy collected from the body can be utilized to activate various microelectronic devices. While some microelectronic devices can work within a fairly broad range of electrical operating conditions, others such as pacemakers require precise voltage levels and voltage regulation for correct operation. Thus, certain classes of electronic devices powered by implantable energy sources will require careful attention not only to energy and power considerations, but also to voltage scaling and regulation. This requires appropriate interfacing between the energy harvesting device and the energy consuming microelectronic device. The present feature article provides an overview of the recent research activity in the area of implanted biofuel cells operating in vivo. Challenges and perspectives in these studies are addressed, giving particular attention to the interfacing between biofuel cells and microelectronic devices. The future holds the prospect for implanted biofuel cells that extract electrical energy directly from the human body, for the powering of implantable biomedical devices. These bioelectronic synergistic systems lay the foundation for bionic human hybrids as well as autonomously operating self-powered "cyborgs".

Powering electronic contact lenses: current achievements, challenges, and perspectives

“…BFCs have been envisioned as electrical power sources for implantable bioelectronics [19], and many reports exist in the literature nowadays concerning implantable BFCs [20][21][22][23]. However, in vivo operation possesses some significant hurdles to overcome, since an implanted biodevice would require a long operational lifetime; in case of electronic contact lens applications, the stability issue is, however, moot.…”

Direct bioelectrocatalysis at the interfaces by genetically engineered dehydrogenase

“…[1][2][3][4][5] The recent advances in translating the biomolecular mechanisms into the hybrid materials and system designs promise novel methodologies that may transform some of the authors' engineering approaches. [6][7][8][9][10][11][12][13] One of the major challenges in such systems is to have control at the bio-nanomaterial interface. The biomolecules need to be integrated at the material interfaces without compromising their spatial distribution, organisation and orientation-dependent activity within a desired proximity.…”

“…9,12,14 However, their spatial distribution with the desired orientation on the solid surfaces, operational stability and long-term reuse are among the critical parameters that limit their wide-range integration to functional materials. 2,[10][11][12][13][14][15] There is an urge to develop biological surface functionalisation approaches that will give the ability to control the desired functions at the bio-nanomaterial interfaces with tunability over a multitude of scales.…”

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“…In EFCs, the oxidation and reduction processes are catalyzed by the utilization of specific redox enzymes and in MFCs, the catalysts applied are microorganisms. The exploration of naturally occurring processes and phenomenon for the generation of electricity is the most beneficial feature of biofuel cells [5]. They are biocompatible, cheap, selective, and effective at mild temperatures and neutral pH.…”