H 2 O Systems Update Presentation Paulo Jacob Jennifer Liang - PowerPoint PPT Presentation

H 2 O Systems Update Presentation Paulo Jacob Jennifer Liang Jonathan Tejada Ami Yamamoto Joy 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

Revising the Dimensions V = E · d d = V / E Size of eukaryotic cell ~ 100 µm = (25V) / (1–5 × 10 5 V/m) = 50 – 250 µm Use 127µm electrode gap

Steel Plate Dimensions 0.4 cm 1 cm 1.9 cm 1.2 cm 1.9 cm 10 cm 1.3 cm 5 cm

Attachment Issues

Flow Visualization Purpose: To confirm that water will flow through our system at a reasonable rate. 500 µ m

Stainless Steel: Schematic Syringe Tubing Water in Water out Shimstock Clamps Plastic plates

Result Main Issue : Leakage from inlet/outlet Solution : Use sealant to minimize leakage

Modeling Water Flow 500 µ m

Titanium: Schematic 127 µm

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 = ε cl ] – Decrease in concentration = Indication of cell lysis.

Experiment Set Up To control flow rate, will apply a constant load → constant pressure Weight Water In Water Out Power Supply

Work in Progress • Anodizing Titanium – Consulting Professor Sadoway • Polarizing Stainless Steel and Ti – Observe electrode reaction with H 2 O (corrosion). • Growing bacteria culture • Testing

Gantt Chart 2/9-2/22 2/23-3/15 3/16-4/5 4/6-4/26 4/27-5/10 5/11-5/18 Research Design Material Acquisition Construction Testing Modification Final Presentation Preparation Before spring break: Anodize Ti and polarize electrodes .

Website • http://web.mit.edu/3.042/team3_06/update s.html

Question • Questions?