P15611: Digital Microfluidics Packaging Design Review P15611: Digital Microfluidics Packaging
Presentation Summary - 1 Background: 2 - 4 System Analysis: 5 - 7 Concept Development: 8 - 12 System Level Proposal: 13 - 18 Engineering Analysis: 18 - 24 Action Items: 25 - 29
Problem Statement - 2 The goal is to create an enclosure that can deliver fluid and provide a controlled environment for the DMF device. Must allow easy camera and microscope access. The enclosure must allow for electrical connections to the chip. Should allow for environmental control and monitoring to maintain droplet size. Must adhere to electrical safety and cleanliness standards. Should allow for easy access to chip between tests.
Current Device - RIT - 3 Eventual goal: ELISA Assay Will be used in the DMF Lab Resistance Model between Plates 120 Channels Lacks Environmental Controls Open Chip Enclosure
Current Device - DropBot - 4 University of Toronto’s Wheeler Lab 320 Channels Microdrop Graphical User Interface Large Enclosure Measures Position, Velocity, and Driving Force http://microfluidics.utoronto.ca/dropbot/
Customer Requirements - 5
Engineering Requirements - 6
House of Quality - 7 Top 4: Environmental Control, Budget, Maximum Size, Test Setup Time Size & Setup Time were more important than we expected.
Functional Decomposition -8
Morphological Chart - 9
Morphological Chart - 10
Selection Criteria-11 Cost Completion Time Set-Up Time Ease of Chip Access Size Weight Environmental Stability Material Quality (Viewing) Budgetary Efficiency Ease of Use Power Precision/Accuracy
Concepts - 12 Concept I: Minimal Design Concept III: Alternate Design Concept II: Dream Machine Concept IV: Selected Design
Pugh Charts - 13 Concepts III & IV are both are similar in scope Concept I offers few features and does not make most efficient use of budget
Concept Sketch - 14 http://www.elveflow.com/product/microfluidic-temperature-controller
Concept Sketch - 15
Systems Architecture - 16
Systems Architecture - 17
Feasibility - Humidity/Temperature - 18 Relationship between humidity and temperature Warm air holds more moisture than cool air Approximate relationship: 20 degree F increase decreases humidity by 1/2 Temperature 40 degree F 60 degree F 80 degree F Relative Humidity 100% 50% 25%
Feasibility - Humidity/Temperature - 19 Relative Humidity = Partial Pressure/Equilibrium Vapor Pressure We are attempting to put the system to its equilibrium point Vapor Pressure of water only interacts with water (Dalton’s Law) Lowering temperature lowers equilibrium vapor pressure of all reagents http://crescentok.com/staff/jaskew/isr/chemistry/class16.htm
Feasibility - Temperature Monitoring- 20 Thermocouple costs range from a few dollars all the way up to 30 dollars per couple. More expensive couples are electrically insulated. The thermocouples leads can be as small as .0005 inches. Standard couple calibrations allow for versatility. http://www.omega.com/pptst/HSTC.html
Feasibility - Humidity Monitoring - 21 Digital measurement of the Humidity can done using either capacitive or resistive sensors. The cost for the individual sensors range from a few dollars up to 100 dollars. The actual size of a capacitive sensor is a 3x3 millimeter squared. http://www.silabs.com/products/sensors/humidity-sensors/Pages/default.aspx
Feasibility - Viewing access - 22 http://www.zeiss.com/microscopy/en_us/home.html
Feasibility - Fluid Delivery - 23 Sandia National Laboratories: Microfluidics hub with capillary tubes as fluid delivery medium. An applied pressure source is used to form a droplet on the surface of the chip. DMF actuation separates the droplet from the capillary tubing. Kim, Hanyoup, Michael S. Bartsch, Ronald F. Renzi, Jim He, Jim Van De Vreugde, Mark R. Claudnic, and Kamlesh D. Patel. "AUTOMATED SAMPLE PREPARATION PLATFORM FOR NEXT GENERATION DNA SEQUENCING USING A DIGITAL MICROFLUIDIC HUB." (n.d.): n. pag. Sandia National Laboratories, United States of America. Web. <http://www.rsc.org/images/LOC/2011/PDFs/Papers/253_1121.pdf>
Feasibility Peer Review - 24 Look into pressure controls Consider material for enclosure Preference towards plastic for insulation and electrical safety Glass to prevent autofluorescence effects when using a microscope
Engineering Analysis Needed - 25 Virtual Model Analysis Determine Compartment Volume Position capillary tubing, sensors, etc Ensure correct sizing of system components Calculate temperature requirement for desired relative humidity. Calculate pressure required to dispense the desired volume of fluid.
Test Plan - 26 Test Capillary Function Verify fluid delivery Test Humidity and Temperature Sensors Verify sensor accuracy Test Microscope Compatibility Verify fluorescence compatibility Verify microscope can focus
Project Plan-Subsystems Design - 27
Projected Budget - 28
Risk Assessment - 29
Questions?
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