Roxby, DN, Ting, S & Nguyen, HT 2017, 'Polypyrrole RVC Biofuel Cells for Powering Medical Implants', 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Annual International Conference of the IEEE Engineering in Medicine and Biology Society, IEEE, Seogwipo, South Korea, pp. 779-782.View/Download from: Publisher's site
Batteries for implanted medical devices such as pacemakers typically require surgical replacement every 5 to 10 years causing stress to the patient and their families. A Biofuel cell uses two electrodes with enzymes embedded to convert sugar into electricity. To evaluate the power producing capabilities of biofuel cells to replace battery technology, polypyrrole electrodes were fabricated by compression with Glucose oxidase and Laccase. Vitreous carbon was added to increase the conductivity, whilst glutaraldehyde acted as a crosslinking molecule. A maximum open circuit potential of 558.7 mV, short circuit current of 1.09 mA and maximum power of 0.127 mW was obtained from the fuel cells. This was able to turn on a medical thermometer through a TI BQ25504 energy harvesting circuit, hence showing the powering potential for biomedical devices.
Roxby, DN, Tran, N, Yu, P-L & Nguyen, HT 2016, 'Effect of Growth Solution, Membrane Size and Array Connection on Microbial Fuel Cell Power Supply for Medical Devices', Proceedings of the 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society 2016 EMBC, International Conference of the IEEE Engineering in Medicine and Biology Society, IEEE, Orlando, USA, pp. 1946-1949.View/Download from: Publisher's site
Implanted biomedical devices typically last a
number of years before their batteries are depleted and a
surgery is required to replace them. A Microbial Fuel Cell
(MFC) is a device which by using bacteria, directly breaks
down sugars to generate electricity. Conceptually there is
potential to continually power implanted medical devices for
the lifetime of a patient. To investigate the practical potential of
this technology, H-Cell Dual Chamber MFCs were evaluated
with two different growth solutions and measurements
recorded for maximum power output both of individual MFCs
and connected MFCs. Using Luria-Bertani media and
connecting MFCs in a hybrid series and parallel arrangement
with larger membrane sizes showed the highest power output
and the greatest potential for replacing implanted batteries.
Roxby, DN, Tran, N, Yu, PL & Nguyen, HT 2015, 'Experimenting with Microbial Fuel Cells for Powering Implanted Biomedical Devices', Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS, International Conference of the IEEE Engineering in Medicine and Biology Society, IEEE, Milan, Italy, pp. 2685-2688.View/Download from: Publisher's site
Microbial Fuel Cell (MFC) technology has the ability to directly convert sugar into electricity by using bacteria. Such a technology could be useful for powering implanted biomedical devices that require a surgery to replace their batteries every couple of years. In steps towards this, parameters such as electrode configuration, inoculation size, stirring of the MFC and single versus dual chamber reactor configuration were tested for their effect on MFC power output. Results indicate that a Top-Bottom electrode configuration, stirring and larger amounts of bacteria in single chamber MFCs, and smaller amounts of bacteria in dual chamber MFCs give increased power outputs. Finally, overall dual chamber MFCs give several fold larger MFC power outputs.
Roxby, DN, Tran, N & Nguyen, HT 2014, 'A Simple Microbial Fuel Cell Model for Improvement of BiomedicalDevice Powering Times', 2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2014, International Conference of the IEEE Engineering in Medicine and Biology Society, Institute of Electrical and Electronics Engineers ( IEEE ), Sheraton Chicago Towers and Hotel, Chicago, United States of America.View/Download from: Publisher's site
This study describes a Matlab based Microbial Fuel Cell (MFC) model for a suspended microbial population, in the anode chamber for the use of the MFC in powering biomedical devices. The model contains three main sections including microbial growth, microbial chemical uptake and secretion and electrochemical modeling. The microbial growth portion is based on a Continuously Stirred Tank Reactor (CSTR) model for the microbial growth with substrate and electron acceptors. Microbial stoichiometry is used to determine chemical concentrations and their rates of change and transfer within the MFC. These parameters are then used in the electrochemical modeling for calculating current, voltage and power. The model was tested for typically exhibited MFC characteristics including increased electrode distances and surface areas, overpotentials and operating temperatures. Implantable biomedical devices require long term powering which is the main objective for MFCs. Towards this end, our model was tested with different initial substrate and electron acceptor concentrations, revealing a four-fold increase in
concentrations decreased the power output time by 50%. Additionally, the model also predicts that for a 35.7% decrease in specific growth rate, a 50% increase in power longevity is possible.