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?