Towards disposable microbial fuel cells: Natural rubber glove membranes Jonathan Winfield a,* , Lily D. Chambers b , Jonathan Rossiter b , John Greenman c , Ioannis Ieropoulos a a Bristol Robotics Laboratory, University of the West of England, Bristol, UK b Bristol Robotics Laboratory, University of Bristol, Bristol, UK c Microbiology Department, University of the West of England, Bristol, UK article info Article history: Received 13 March 2014 Received in revised form 5 August 2014 Accepted 13 September 2014 Available online 18 October 2014 Keywords: Microbial fuel cell Natural rubber Cation exchange membrane Biodegradation Power overshoot abstract Natural rubber from laboratory gloves (GNR) was compared to cation exchange membrane (CEM) in microbial fuel cells (MFCs). GNR-MFCs immediately generated power indicating the availability of proton transfer pathways in the material, which is contrary to previous research using condom natural rubber membranes. Under bi-directional resistance sweeps, CEM-MFCs produced higher power but were less stable than GNR. Stability proved the valuable trait over 96 h periods under fixed resistances where GNR-MFCs produced 26% higher power than CEM-MFCs and reduced COD by 88% compared to 73% achieved with CEM. Anolyte conductivity increased more significantly for CEM but at the same time pH levels were more marked, a factor that may have contributed to instability. Under com- posting conditions, GNR samples degraded 100% after 285 days whilst GNR-MFC mem- branes were still intact and operational after 493 days. This innovative research could lead the way in producing inexpensive, disposable MFCs with controllable degradation. Copyright © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. Introduction Microbial fuel cells (MFCs) produce power by employing bac- teria to breakdown organic substrates including pollutants from undesirable waste sources making the technology attractive as a new green source of energy with concomitant clean-up. The ability to produce power as a direct conse- quence of the treatment of waste opens the door to a number of potential applications including remote power sources [1], wastewater treatment [2] and environmental sensors [3]. Scale-up is however limited as materials are rarely compatible with the environment and expensive, in particular the cation exchange membrane (CEM). Recently, alternative and inex- pensive materials have been tested to replace conventional CEM including j-cloth [4], ceramic [5] and biodegradable bag [6]. To further increase the applicability of the technology, waste materials could be utilised, as recently reported using natural rubber (NR) membranes derived from condoms [7]. That study demonstrated that the process of biodegradation of a material could be beneficial to the operator by facilitating proton exchange between the anode and cathode electrodes; on the other hand the material appeared more stable over the long term and was not affected by biofouling as is often re- ported with CEM [8]. In order to verify that NR can be a suitable CEM alternative, other sources of NR need to be investigated. * Corresponding author. Tel.: þ44 (0)117 3286178; fax: þ44 (0)117 3283960. E-mail address: jon.winfield@brl.ac.uk (J. Winfield). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy 39 (2014) 21803 e21810 http://dx.doi.org/10.1016/j.ijhydene.2014.09.071 0360-3199/Copyright © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.