Detailed Design Review

Detailed Design Review
P15611: Digital Microfluidics Packaging
Presentation Summary - 1
●
●
●
●
●
●
●
Requirements/Test Plan
Risk Assessment
Individual Solutions
System and Drawings
Bill of Materials
Schedule
Questions/Discussion
Engineering Requirements - 2
Revisions:
● Droplet Size Updated to Reflect Reservoir Size
● Temperature Range Corrected
Testing Plan - 3
● Some are straightforward: Reagent Ports,
Max Weight
● Fluid delivery test will be straightforward
due to new design
● Testing Humidity Accuracy seems
challenging, procedures require specialist
equipment
Safety Test - 4
● Set-up enclosure and close so that the
magnetic catch makes contact
● Confirm latch keeps enclosure closed
● Make sure no current is going inside
of enclosure when open
Fluid Delivery Test Plan - 5
● Set-up enclosure
● Pipette specified amount of fluid in
capillary tube
● Confirm fluid can be drawn out by
electrowetting
Microscope Compatibility Test - 6
● Place whole enclosure under microscope
● Focus chip using light on microscope
● Confirm chip can be focused and there is
clear resolution
Temperature Control Test - 7
●
●
●
●
●
Monitor temperature of enclosure
Turn on cooling device
Run for 5 minutes
Record temperature over time
Confirm temperature of enclosure is
decreasing
System Test - 8
●
●
●
●
Deliver fluid to chip
Set temperature
Control droplet using GUI
Confirm that whole system works together
Risk Assessment - 9
Risk Assessment: Humidity - 10
● Reduce risk of condensation,
to keep imaging clear
● Condensation occurs below
dew point
● Assumed room relative
humidities 20-60%,
75% worst case
● Calculated for temperatures
between 6oC - 20oC
Risk Assessment: Humidity - 11
● Relative humidity = partial
pressure/vapor pressure
● We found the partial of air at a
given humidity at room temp
● 60 and 75% relative humidity
are extreme values
● Dewpoints at initial 60% RH
have dewpoints around 13 °C
or 55 °F
Risk Assessment: Condensation - 12
Risk Assessment: Safety - 13
● Protect user from electric exposure
● Sugatsune - Electronic Magnetic Catch
● Detects when door is closed (“Power
when on”)
● Aims to prevent power into the
enclosure when open
Fluid Delivery: Original Solution - 14
● SFC Quick Connects
○ Work well with multiple ports
○ Easy integration of reservoir
○ Automated delivery
● Doesn't translate to multiple reagents
○ Pressure controls involve fluid
properties
○ Tubing requires cleaning
In the interest of future expansion we moved to a
new concept
Fluid Delivery: New Solution - 15
SME: Dr. Michael Schrlau
● Eppendorf Microloader Tips
○ Simple solution
○ Easy to integrate into current Design
○ Ability to use with pipettes in labs
● Seamless integration of new reagents
○ Multiple reagents per test
● Minimal Chip Redesign
● Some difficulty of use in alignment
Cooling Analysis - 16
● Cool a small enclosure and maintain temperature.
● Analysis of Free Convection Flow for flow of heat into
the enclosure from the environment.
● Use of Nusselt and Rayleigh
numbers for a horizontal
plate.
● Constant and volume pressure
assumed.
Cooling Analysis - 17
Cooling Analysis - 18
● Used total resistance to find
the heat rate in since surface
temperatures were unknown.
○ Convection rate of air based
on film temperature less
than 27 degrees from 0°C.
● Equated the inside using
Lumped Capacitance Method.
○ Biot was less than 0.1
● Properties of air referenced from Tables.
Cooling Analysis - 19
● The heat rate is dependent on the time.
The faster the time the more power
required.
● Qcool is in Watts, the temperature
difference between the environment
and enclosure is °C.
● Heating requirement is at most 1
minute to keep heat rate low.
Cooling Analysis - 20
Heat/Cooling - 21
● Cooling will be performed by a
thermoelectric cooler.
● Capable of 6 watt rate.
● Thermoelectric waste heat output
of approximately 10 watts.
● 40 x 40 mm square that is 5 mm thick.
Thermoelectric Cooling - 22
● Peltier Plate
○ Solid State Heat Pump
+No Moving Parts or Fluid
+Small Size
-Low Power Efficiency
-High Cost
(Compared with Vapor Refrigeration)
● Small size accounts for some cons
www.dansdata.com
Thermoelectric Cooling - 23
● Plate gets cold on one side, hot on the other
○ Heat management
○ Material Concerns
● Works well in small enclosures
○ Low amount of heat to remove
● Loses efficiency as heat rises
● Heat Management will be critical
to effective application
www.ebay.com
Heat/Cooling - 24
● Fits over thermoelectric and will act as seal.
● Non Ducted forced convection
resistance of 0.82°C/W.
● Ducted forced convection
resistance of 0.53°C/W
● 600 LFM or approximately 7 CFM
● Measures 45 x 45 x 25 mm
Heat/Cooling - 25
● Fan capable of 7.0 CFM with 0.5
in H20 (~120 Pa).
● Overcomes any pressure loss from
the heat sink.
● Will run off of 12V power supply.
● Measures 75 x 75 x 25 mm.
Heat/Cooling - 26
3D Printer Specifications - 27
● Fortus 360MC
● 0.8 cubic foot build
space
● Soluble or breakaway
support structures
● ±0.127mm (±.005”)
achievable accuracy
Available Materials
ABSi
ABS-M30,ABS-M30i
ABS-ESD7
Nylon 12
PC-ABS
PC,PC-ISO
Ultem 9085
PPSF
Temperature & Humidity Sensor - 28
Adafruit HTU21D-F Temperature &
Humidity Sensor
● Will report temperature & humidity
data to computer
● Data can be incorporated into GUI
to confirm experimental readiness
● Data can also be recorded to
confirm experimental validity
Camera Stand - 29
● Zykkor C082 Copy Stand
○ Tripod Mount Head
○ Adjustable Camera Base
● 15.75 x 19 inch base
● 27.95 inches tall
● 10 lbs of our 50 lb limit
CAD Model: Full Enclosure - 30
Assembly - 31
Fluid Delivery - 32
● Leader for straight
entry
● Tip lead for droplet
positioning
● Microloader for use
with standard micropipettes
Tip
Lead
Microloader
Leader
Snap-in
plugs
Microloader
Pipette
Tip
Camera View Set-up - 33
● Adjustable camera
height for focus
● Universal DSLR
adapter
● Possibility of
modification for
webcam use
Bill of Materials - 34
● Indented BOM
● Includes:
○
○
○
○
○
Part Description
Vendor/Manufacturer information
Quantity required
Price (Including shipping)
Lead Times
Bill of Materials - 35
Bill of Materials - 36
Lead Times - 37
● 3D Printed Parts (Enclosure) - < 1 week
● McMaster-Carr (Glass, Gasket, etc.) - < 1
week
● Already Ordered - Camera Stand - 1 week
● Peltier Plate - < 1 week
● Heat Sink - < 1 week
Budget - 38
Budget:Estimated vs. Actual Cost - 39
Budget-Actual Cost Breakdown - 40
Schedule - 41
Questions/Discussion