Multistream Flowrate Controller

1
Multistream Flow-rate Controller

• Team Members
• Betsy Appel
• Joe Grudzinski
• Ibrahim Khansa
• Abdikarim Mahamud
• Steven Skroch
• Alyssa Walsworth
• Client Tom Pearce, Dept. of Biomedical
  Engineering
• Justin Williams, Ph.D.
• Advisor Wally Block, Ph.D.

2
Problem Statement

• Client requests a device to generate, maintain
  and control the rate of flow of six channels in a
  microfluidic system.

3
Client Motivation

• Conducting research in neural interface
  technology
• Experimenting with multistream laminar flow
• Desires ability to quickly alter cell environment
• Ultimately used for targeted drug delivery

4
Design Requirements

• Produce consistent and reproducible flow rates
• Flow rate range 10 µL/min to 1.0 mL/min
• Easily control flow rate
• Electronically controlled system
• Both infusion and withdrawal of fluids
• Flow must be continuous

5
Background

• Microfluidics Movement of fluids on the scale of
  microliters per minute
• Allows precise fluid delivery for targeting parts
  of culture
• Laminar flow Two streams mix only by diffusion

6
Current System
7
Electrolysis-driven gas pump

• Ibrahim Khansa
• Alyssa Walsworth

8
Basic Design

• Cathode immersed in acidic solution
• Hydrogen gas produced by
• 2H(aq) 2e- ? H2(g)
• H2 volume directly proportional to current
  intensity
• Flow rate

30 (Current) (Molar volume)
F
9
Design
The other half-cell and the salt bridge are not
depicted
10
Enrichments
11
Advantages

• Great repeatability
• Pulse-free
• Little maintenance needed
• Inexpensive
• Can deliver unlimited volumes of fluid
• Very large range of flow rates

12
Advantages (continued)

• Little calibration needed
• Fluid container can be discarded after use

13
Cons

• Possibility of H2 dissolving in the fluid
• Solution

Diaphragm
14
Ceram Pump

• Betsy Appel
• Joe Grudzinski

15
FMI CeramPump

• No Valves
• One moving part
• Rotating and reciprocating ceramic piston
• Small and compact
• Flow rate range 0-4600 mL/min
• 600 strokes/min

Fluid Metering, Inc. http//www.fmipump.com
16
Easy Adjustment
Fluid Metering, Inc. http//www.fmipump.com
17
(No Transcript)
18
Pros

• Can change flow rate instantaneously
• Infinite fine flow adjustment
• Accuracy 1 Precision 0.5
• Instant reversibility
• Modular design
• Ability to aspirate, dispense, meter, flush and
  wash

19
Cons

• Flow pulsates
• High rate may not be a problem
• Price
• No computerized control

20
Compressor Pump

• Abdikarim Mahamud
• Steven Skroch

21
Compressor pump
22
Components

• Compressor
• Pressure controller
• Software
• Pressure chamber
• Diaphragm
• Venturi valve

23
Pros
Electric compressor safe no oil contamination.
Pressure controller controlled by PC
No moving parts in venturi valve
24
Cons

• Venturi flow rate is higher than the in-flow
• Possible pressure fluctuations, flow rate
  affected
• Limited reservoir size
• Possible diaphragm limitation

25
Future Work

• Evaluate all nine designs
• Pick final design based on client requirements
• Order parts
• Construct prototype
• Test functionality of device

26
Questions?