(1993-)

Aarne Halme, Xiachang Zhang

Biological fuel cell is a device that realizes the conversion of biochemical energy into electrical energy. The basic principle is that the process of substrate oxidation by microorganisms or enzymes in the fuel cells offers electrons for electricity production. Since the conversion is not restricted by the Carnot cycle, the theoretical efficiency can be as high as 90%. There are two types of microbial fuel cell. One involves the utilization of electroactive metabolites, e.g., hydrogen, converted by microbial metabolism or enzyme reaction from substrate, and another involves the utilization of mediators as electron transporters from a certain metabolic pathway of the microorganism or enzyme to electrodes. So far we have studied the structure (including the size and shape) of the fuel cell device, modelling and control of the process. Also, we have tested two kinds of microorganism (baker's yeast and bacteria from Finnish Gulf) in our fuel cell system. In the current study, we are going to study the small enzyme fuel cell and try to apply the enzymatic fuel cell for small electronic devices like mobile phone. The detailed information on the enzymatic fuel cell is available.

Microorganisms used for the biological fuel cell

After using a baker's yeast as microorganism in the biological fuel cell a few years ago, bacteria have been used for the study. The bacteria were obtained from the bottom of the Finnish Gulf. One of the main reasons to use bacteria is that the bacteria could survive in a higher pH solution. The higher pH solution offers a lower anodic potential, which makes a higher potential difference in the terminals of the fuel cell.

Structure of the fuel cell

Different shapes of the anode and the cathode are studied. It seems that the thickness of the anode compartment should be less than 2 cm and larger membrane area is needed for a high energy output. On the other hand, the size of the biological fuel cell is important factor for the efficient energy conversion from chemical to electrical energy. The smaller size of the fuel cell improves the efficient.

Modelling and control of the biological fuel cell processes

The model was set up on the basis of the experimental results and analysis of biochemical and electrochemical processes. Simulation of the process shows that the model describes the process reasonably well. The analysis of model simulation illustrates how the current output depends on the substrate concentration, mediator concentration and other main variables. The relationship between the current output and over-voltage is revealed from the modelling study. Based on the experimental and modelling of the process, proper control of bacteria metabolism can convert most of substrate to electroactive intermediates.

Reaction diagram of the biological fuel cell

A biological fuel cell device

Publications

• Aarne Halme, Matti Korhola, Anja Ranta, Jussi Suomela and Zhang Xia-Chang,
  Patent: "Biocatalytic direct alcohol fuel cell",
  US7384701 (B2); FI119267 (B1), 2008.
• Aarne Halme and Zhang Xia-Chang,
  "Biological fuel cells: Processing substrates to electricity by the aid of biocatalysts,"
  in Bioseparation and Bioprocessing, Ganapathy Subramanian (Ed.), Weinheim: Wiley-VCH, 2007, pp. 355-382.
• M Smolander, H Boer, M Valkiainen, R Roozeman, M Bergelin, J-E Eriksson, X-C Zhang, A Koivula and L Viikari,
  "Development of a printable laccase based biocathode for fuel cell applications,"
  Enzyme and Microbial Technology, 2007.
• XiaChang Zhang, Anja Ranta and Aarne Halme,
  "Direct methanol biocatalytic fuel cell - Considerations of restraints on electron transfer,"
  Biosensors and Bioelectronics, Vol. 21, pp. 2052-2057, 2006.
• Anja Ranta, Xiachang Zhang, Sami Kielosto and Aarne Halme,
  "Thin Biofuel Cells as Power Source for Advanced RFID Applications,"
  in Proc. Small Fuel Cells 2005, Washington 2005, 2005, 1 p.
• Xiachang Zhang, Anja Ranta and Aarne Halme,
  "Miniature enzymatic fuel cell and its applications,"
  in Proc. The Small Fuel Cells Conference, Arlington 2004, 2004, 1 p.
• Anja Ranta, Xiachang Zhang and Aarne Halme,
  "Conceptual prototype of a direct methanol biocatalytic fuel cell,"
  in Abstracts of the 5th annual international symposium Small Fuel Cells, Serge Pan and Craig Wohlers, Massachusetts: The Knowledge Press, 2003, 1 p.
• Xiachang Zhang, Anja Ranta and Aarne Halme,
  "Effect of different catholyctic oxidants on the performance of a biocatalytic methanol fuel cell,"
  in Meeting abstracts no. 1239, Florida, USA: 2003, 1 s.
• A Ranta, X Zhang and A Halme,
  "Enzymatic Fuel Cell: Biochemical Energy Conversion, Power Sources for the New Millenium,"
  in Proceedings of the International Symposium of ECS, Vol. 2000-22, M.A Ryan, S Surampudi and M Jain (eds.), Pennington, USA: The Electrochemical Society Inc, 2001, pp. 108-117.
• A Halme, X Zhang and A Ranta,
  "Study of Biological Fuel Cell,"
  in Proc. Small Fuel Cells 2000, New Orleans, 26-28 April 2000, 2000.
• X Zhang and A Halme,
  A biofilm reactor for a bacteria fuel cell system,
  Espoo: Teknillinen korkeakoulu, 1999. (Laboratory of Automation Technology, Research reports, 20).
• A Halme, X Zhang and N Rintala,
  "Monitoring and control of a bacteria fuel cell process by colour analysis,"
  in Proc. The 7th International Conference on Computer Applications on Biotechnology, Osaka, Japan, 1998, Osaka: 1998, s. 462-467.
• A Halme, A Visala and X Zhang,
  "Process modelling using the functional state approach,"
  in Multiple model approaches to modelling and control, T. Johansen R. Murray-Smith, Lontoo: Taylor & Francis, 1997, s. 121-143.
• X Zhang and A Halme,
  Effect of size and structure of a bacteria fuel cell on the electricity production and energy conversion rate,
  Espoo: TKK/Automaatio, 1997. (Automation technology laboratory, Research reports, 17).
• A Halme and X Zhang,
  "Biofuel cell utilizing Saccharomyces cerevisiae - modelling of the process,"
  in Preprints of the 6th International Conference on Computer Applications in Biotechnology, Germany: 1995, 165-170.
• X Zhang,
  Aspects of modelling and control of bioprocesses,
  Espoo: Teknillinen korkeakoulu, 1995. (Automation Technology Laboratory; Series A: Research Reports, 13).
• X Zhang and A Halme,
  "Modelling of a microbial fuel cell process,"
  Biotechnology Letters, Vol. 17, no. 8, p. 809-814, 1995.
• X Zhang and A Halme,
  A Summary of the Study of Bioelectrochemical Fuel Cell by using Saccharomyces Cerevisiae,
  Espoo: Teknillinen korkeakoulu, 1994. (Helsinki University of Technology, Automation Technology Laboratory. Series A, Research Reports, 10).
• X Zhang, A Visala, A Halme and P Linko,
  "Functional state modelling and fuzzy control of fed-batch aerobic baker's yeast process,"
  Journal of Biotechnology, Vol. 37, no. 2, 94-103, 1994.
• X Zhang, A Visala, A Halme and P Linko,
  "Functional state modelling approach for bioprocesses,"
  Journal of Process Control, Vol. 4, no. 3, 127-134, 1994.
• X Zhang and A Visala,
  "Functional States, Local Models and Estimation of Biomass in An aerobic Yeast Culture,"
  in Proc. Bioprocess Engineering Meeting, Stockholm, 1992, Lund: Biotechnology Research Foundation, 1992, 140-146.
• X Zhang, A Visala and A Halme,
  "A Kinetic Model of Mammalian Cell Cultures,"
  in Proc. 2nd IFAC Symposium on Modeling and Control of Biotechnical Processes, Colorado, 1992, Oxford: Pergamon press, 1992, 367-370.
• X Zhang, A Visala and A Halme,
  A Kinetic Model of Mammalian Cell Cultures and Fitting it to the Sp 2/0-Ag 14 Culture,
  Espoo: TKK/Automaatiotekniikan lab, 1992. (Helsinki University of Technology, Automation Technology Laboratory. Series A, Research reports, 7).