Transcript Anode - Calvin College

Calvin College
Engineering Senior Design
Team 10
March 28, 2008
Outline
 Introduction
 Design
 MFC
 Power Regulation
 System Monitoring
 Feed/Waste System
 Budget
 Moving Forward
Team 10: Members
Jared Huffman
Brianna Bultema
Achyut Shrestha
Chris Michaels
Project Division
Four Main Parts of Our
Biobattery Project
 Microbial Fuel Cell
 Electrical Monitoring
 Electrical Regulation
 Feeding and Case
Design
Introduction
Design
Budget
Moving Forward
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
Introduction
Design
Schematic courtesy of Derek R. Lovely
(Microbial Energizers: Fuel Cells the Keep Going?)
Budget
Moving Forward
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
Design
Budget
Moving Forward
Design Goals
 USB Power output
 5V, 5% tolerance
 0.1-0.5A
 Refillable Food Supply with Alert
 Semi-Continuous
 System Monitoring
 User friendly
 Indicates Failure Mode
 Improved Power/Volume Ratio
 Anode Cube
Introduction
Design
Budget
Moving Forward
Anode Cube
Waste
Output
Food
Input
Electrode
Location
(Each Face)
MFC Design
Regulation
Monitoring
Food/Waste
Budget
Design
 Fuel cell arrangement and composition
 Will use a combination of serial and parallel circuit
design

Lower chance of battery and circuit failure
Introduction
Design
Budget
Moving Forward
Design
 Regulation
 Must output 4.75V-5.25V and 100mA-500mA for USB
compatibility
 Must overcome low current problem
 Must step up voltage from about 3.3V to 5V
 Will use the Maxim MAX1524 Boost Controller
Introduction
Design
Budget
Moving Forward
Regulator Circuit
Fig. Regulator circuit
Introduction
Design
Budget
Moving Forward
Parallel vs. Series Configuration
Regulator
M
F
C
Regulator
M
F
C
Fault signal
Monitor
Fig. Parallel configuration
Introduction
Design
Fault signal
Monitor
Fig. Series configuration
Budget
Moving Forward
Parallel configuration
 Parallel configuration of regulator and monitor
circuits
 Preserve system integrity
Introduction
Design
Budget
Moving Forward
MFC Monitor Design
 Goal
 Monitor the status of the system and communicate
relevant status to user
 Requirements
 Update user the system status



feed and waste removal
voltage produced by MFC
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
Design
Budget
Moving Forward
MFC Monitor Design
Voltage output from
MFC
Feed/waste removal
signal
ADC
micro-controller
Fault signal
LCD
Fig. Block diagram
Introduction
Design
Budget
Moving Forward
Monitor Design
Initial State
Waste
Interrupt
Vin MFC
alert
good
Output
interrupt
warning
bad
Fig. State Machine
Introduction
Design
Budget
Moving Forward
MFC Monitor Design
 AVR butterfly kit
 Atmega169 microcontroller
 10 bit ADC & LCD
 Low power
consumption: < 500µA
 RoHS compliant
 No speciality
hardware/software need
for programming
Introduction
Design
Fig. Block diagram
Budget
Moving Forward
Feeding and Waste System
 Food Solution Bladder
 Tubes and Valves
 Thumbscrew Valves to Control Rate
 One Way Valves to Prevent Backflow
 Cubes Fed in Sets of 2, Bottom to Top
 Waste Tank
Introduction
Design
Budget
Moving Forward
Feeding and Waste System
Food Solution Bladder
Filled by User Periodically
Anode
Cube
Anode
Cube
Cathode
Tank
Anode
Cube
Anode
Cube
Waste Tank
Emptied by User Periodically
Introduction
Design
Budget
Moving Forward
Decision-Making Process
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
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
Design
Budget
Moving Forward
Budget
 Preliminary Budget estimation = $750
 Spent
 Geobacter & media
 Testing components such as tubes,
 AVR butterfly kit
 $350
Introduction
Design
Budget
Moving Forward
Budget
 Planned
 Electrodes and membrane
 Feeding and waste system
 Electrical components
 $400
Introduction
Design
Budget
Moving Forward
Budget
 Donation
 Test equipments from chemistry and biology
departments
 Plexiglas, carbon cloth and membrane
Introduction
Design
Budget
Moving Forward
Obstacles and Plans
 Case design
 Need to find a tank for the cathode
 Need to select and acquire a feed bladder
 Must find a waste tank
 Must select an appropriate feed rate
Introduction
Design
Budget
Moving Forward
Obstacles and Plans
 Bacteria testing
 Must have a bio-film formation on the electrode
 Need to select a secondary, non-competitive aerobic
bacteria
 Plan to allow Geobacter to colonize electrodes before
applying secondary bacteria
 Plan to create a large supply of media
Introduction
Design
Budget
Moving Forward
Obstacles and Plans
 Electrical regulation
 Need to order parts

Need SchmartBoard to solder surface mount parts
 Need to test circuit in lab
 Electrical monitoring
 Need to interface the different components with the
monitoring system
 Complete system test
Introduction
Design
Budget
Moving Forward
Questions?