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Ecowatt. Biobattery. Calvin College Engineering Senior Design Team 10 May 3, 2008. Outline. Introduction MFC Power Regulation System Monitoring Feed/Waste System. Team 10: Members. Jared Huffman. Chris Michaels. Achyut Shrestha. Brianna Bultema. Why Biobattery?.
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Ecowatt Biobattery Calvin College Engineering Senior Design Team 10 May 3, 2008
Outline • Introduction • MFC • Power Regulation • System Monitoring • Feed/Waste System
Team 10: Members Jared Huffman Chris Michaels Achyut Shrestha Brianna Bultema
Why Biobattery? • Problems of Conventional Batteries • “Hard to Do” • Interdisciplinary Talents Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Design Goals • USB Power Output • Refillable Food Supply with Alert • Semi-Continuous • System Monitoring • User friendly • Indicates Failure Mode • Improved Power/Volume Ratio • Anode Cube Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Project Division Four Main Parts of Our Biobattery Project • Microbial Fuel Cell • Electrical Monitoring • Electrical Regulation • Feeding and Case Design Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Decision-Making Process • Brainstorm (Group and Individual) • Discuss Design Requirements • Research • Design • Present Design to Team • Refine Design • Present Refined Design to Team • Order Parts • Assembly • Testing Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
How Microbial Fuel Cells (MFC) Work Story of Electrons: • Anode • Electrons from Acetate to Geobacter • Geobacter sends electrons outside itself to electrode • Cathode • Electrons combine with Oxygen and Protons to form water Schematic courtesy of Derek R. Lovely (Microbial Energizers: Fuel Cells the Keep Going?) Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Microbial Fuel Cell Design • Species: Geobacter Metallireducens • Most Efficient Colonization and Power Density • Widely tested • Membrane: Cellophane vs Nafion • Balance Cost and Permeability • Electrode: Carbon Cloth vs Carbon Porous Block Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Anode Cube Waste Output Food Input Electrode Location (Each Face) Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Regulated Power Supply 5V USB Power Switching 5V 3V OC AVR Butterfly Temperature sense Vin 3V Power Management Power management module Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Regulation • Output: 4.75V-5.25V, 100mA-500mA for USB Compatibility • Step up voltage from 3.0V to 5.0V • Research and Decisions • Maxim MAX1524 Boost Controller Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Regulation Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Monitoring System • Goal • Monitor the status of the system and communicate relevant status to user • Requirements • Update user the system status • voltage produced by MFC • Optimum temperature range 20 – 35 C • circuit integrity, for e.g. over-current, short circuit • Use minimum power to monitor the system • User friendly • Components RoHS compliant and lead free Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Monitoring System Program control logic Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Monitoring System Program control logic Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Monitoring System • AVR butterfly kit • Atmega169 micro-controller • Low power consumption: < 500µA • RoHS compliant • WinAVR for coding & compiling • AVR Studio for debugging and loading code Block diagram Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Feeding and Waste System Food Solution Bladder Replaced by User Periodically Cathode Tank Anode Cube Anode Cube Anode Cube Anode Cube Waste Tank Emptied by User Periodically Introduction Microbial Fuel Cells Regulation Monitoring Feeding/Case
Conclusion • Achieved Goal of Advancing Existing Designs Toward Feasible Product • Future Projects • Produce Smaller Cube: Fabrication Methods • Full Testing of Cellophane Membrane • Platonized Electrodes to Allow Air Cathode
Acknowledgements • Professor Ray Hozalski, Civil Engineering, University of Minnesota – Twin Cities, for samples/supplies of electrodes, membranes, and information on MEAs. • Chris Harrington, Graduate Student Researcher, University of Minnesota – Twin Cities, for help with implementation procedures. • Professor John Wertz, Biology Department, for assistance in Microbiology growth and experimentation. • Professor J. Aubrey Sykes, Engineering Department, for his ongoing role as the senior design advisor and for all of this feedback about our project. • Professor Randall Brouwer, Engineering Department, for supplying VHDL code for ADC interface. • Sam Brower, Media Productions Calvin Alum, for various visual design and photographic assistance. • Bob DeKraker, Engineering Department, for logistical support with procurement of circuit components. • Rich Huisman, Chemistry Department, for assistance with salt bridge supplies. • Lori Keen, Biology Department, for assistance in biological procurement and lab support. • Professor Walter Rawle, Engineering Department and Senior Design Team Mentor, for meeting with our team and assisting us with the in progress reviews. • Professor Gemma Reguera, Michigan State University, for providing technical information and expertise.
