1. First Design Review Matthieu Giraud-Carrier Kyra Moon 02/08/2011

2. Overview Introduction Purpose Motivation Product Design Project Requirements Design Specifications Customer Needs Alternate Concepts Concept Selection and Generation Fundamental Design Issues Critical Concepts Schedule Current and Future Work

3. Introduction—Purpose Basic goal: Build a microfluidic impedance spectroscopy system. In other words -- build a chip with a small channel which can be filled with fluids (primarily protein solutions) and then analyzed.

4. Introduction—Motivation Medical field – researchers can learn how these proteins interact by observing the electrical properties of these solutions over a wide frequency range. Creating microfluidic systems out of inexpensive materials would facilitate medical research by making it less expensive and easier to use.

5. Introduction—Product Design The final product: A chip of a few square inches. Basic elements: Waveguide runs through the chip and is terminated by an SMA connector on either side. Microfluidic channel close to the waveguide (three copper lines) in the center of the chip. Reservoir that ensures the channel will always be full during analysis. The user will also be able to connect to these reservoirs through a standard pressurized port.

6. Design Specifications Bandwidth: 100MHz to 7GHz Volume of channel: 0.5mm X 1mm X 2cm (10uL) Accuracy (% repeatability): 5% Temperature stability: Within 1 degree Final outputs: Conductivity and Permittivity (from S-Parameters) Develop a numerical model for the waveguide (Sensitivity measures for changes in permittivity and conductivity) Interface between Network Analyzer and Plotting Mechanism (GPIB, LabView, Matlab) Materials: Standard PCB materials (FR-4, FR-2) Sufficient reservoir volume for a 5-minute test Connectors: SMA on board

7. Meeting Customer Needs Metric #Need #MetricUnits Marginal Value Ideal Value 11 Operational frequency range GHz0.1 - 720Hz - 20 23 Volume of channel microliters<10< 5 37,8 Accuracy %<5<1 42 Temperature stability degrees10.2 55 Evaporation time minutes510 64,9 Familiarity of hardware (connectors) Subj. 35 76 Familiarity of software Subj.35 810 Size of the device in 2 2<2

8. Block Diagram A user selects the liquid to be analyzed Liquid is sent into the microfluidic channel through Nanoport connectors. The Network Analyzer gathers information from the chip (using standard SMA connectors) An interface turns the raw data from the analyzer into useful information for the user.

9. Alternate Concepts Using acrylic instead of PCB material. Using a waveguide perpendicular to the microfluidic channel rather than parallel. Using a multilayer board to build the waveguide without direct contact to the channel. Modifying the geometry of the channel and reservoirs and having the waveguide go straight across the chip Making the waveguide run over the top of the channel on the main copper layer. Using vias to avoid the 90 degree angle turns in the copper lines. Using Prepreg to ensure no leakage.

10. Fundamental Design Issues Material Selection: Decide what PCB type material will be optimal for our system. Leakage Prevention: Design the board so that the protein solution can be confined properly to the channel. Signal Path Geometry: Consider how to align the channel and waveguide and how to fit all the connections on the board.

11. Illustrations

12. Concept Generation: Material Selection

13. Concept Generation: Leakage Prevention

14. Concept Generation: Signal Path Generation

15. Schedule

16. Schedule – Critical Path Determine how to set milling depth on machine Learn how to create vias and alignment holes Make several prototypes Have board made professionally

17. Schedule – Categories First category: learning how to use the devices and software. Kyra – HFSS (modeling software), interfaces computer Matthieu – milling machine, CAD software, how to create the boards Second category: physically creating the board It takes time to bond the board, run leakage tests, and create several prototypes Third category: waiting for outside sources Arrival of parts, making the chip professionally We have little control over this category so we need to order early

18. Current & Future Work Kyra is fine-tuning the current HFSS model. We will soon be getting the Prepreg and running several tests to optimize bonding. Still learning how to use the camera system on the milling machine. Using Network Analyzer to run preliminary tests and gain intuition. By next design review: All fabrication issues finalized and optimized. Have a complete working model of our system in HFSS.