H2O SystemsUpdate Presentation
Paulo JacobJennifer LiangJonathan TejadaAmi YamamotoJoy Yuan
March 16, 2006
Update Presentation
• Work Space, Storage, Advisors• Changes in our design• System construction• Flow visualization• Water dielectric breakdown problem• Cell lysis efficiency testing protocol• Works in progress
Work Space, Storage, Advisors
• Lab Space:– Construction of system: 13-5032– Anodizing: Professor Sadoway’s lab– Bacteria culture: 68-074– Running water sample: 68-074
• Refrigerator for bacterial culture:– Undergraduate lab: Building 8
• Outside Contacts:– Michelle Mischke: Bacteria testing and culture– Professor Sadoway: Anodizing
V = E · d
d = V / E
= (25V) / (1–5 × 105 V/m)
= 50 – 250 µm
Size of eukaryotic cell ~ 100 µm
Use 127µm electrode gap
Revising the Dimensions
Steel Plate Dimensions
0.4 cm
5 cm
10 cm
1 cm 1.2 cm1.9 cm
1.3 cm
1.9 cm
Attachment Issues
500 µm
Flow VisualizationPurpose:
To confirm that water will flow through our system at a reasonable rate.
Stainless Steel: Schematic
Tubing
Syringe
Shimstock
ClampsPlastic plates
Water in
Water out
Result
Main Issue: Leakage from inlet/outletSolution: Use sealant to minimize leakage
500 µm
Modeling Water Flow
127 µm
Titanium: Schematic
Titanium
Result
Conclusion:• Leakage from inlet/outlet
• Pressure required for flow is very low
• Water flows through the entire volume within system
Water Dielectric Breakdown
• Concern was raised regarding water dielectric breakdown and possible dangers associated with it.
• Solution: IT WON’T BE A PROBLEM– Water Dielectric Breakdown = 200~300kV/cm– Breakdown Potential for Cell Lysis: 1~5kV/cm– We are aiming at 5kV/cm<<200kV/cm
Protocol for Bacteria Testing
• Bacteria:– E.Coli stock culture– Bacteria concentration: 5cfu/mL
• Highest count in Charles River: ~5cfu/mL
• Water Sample Preparation:– 5mL culture + 35mL distilled water– Stock bacteria concentration: 40cfu/mL
Experiment
• Bacteria concentration quantification before and after each run
• Spectrophotometer measurement– Blank: 5mL LB broth + 35mL distilled water
– Using Beer’s Law, we will find bacteria concentration [ A = εcl ]
– Decrease in concentration = Indication of cell lysis.
Experiment Set Up
Water In
Water Out
Power Supply
Weight
To control flow rate, will apply a constant load → constant pressure
Work in Progress
• Anodizing Titanium– Consulting Professor Sadoway
• Polarizing Stainless Steel and Ti – Observe electrode reaction with H2O (corrosion).
• Growing bacteria culture • Testing
Gantt Chart
Modification
Testing
Final Presentation Preparation
Construction
Material Acquisition
Design
Research
5/11-5/184/27-5/104/6-4/263/16-4/52/23-3/152/9-2/22
Before spring break: Anodize Ti and polarize electrodes.
Website
• http://web.mit.edu/3.042/team3_06/updates.html
Question
• Questions?