Group R 14300 Digital Microfluidics Peter Dunning Paulina

Group R 14300 – Digital Microfluidics Peter Dunning Paulina Klimkiewicz Matthew Partacz Andrew Greeley Thomas Wossner Wunna Kyaw

Problem Statement • Need for point of care medical testing devices where access to conventional tests is restricted o Ex: Doctor’s Offices, Remote Areas, Battlefields • A solution must be portable and cheap

Problem Statement • • Lab-on-a-chip devices are capable of miniaturizing and automating biological protocols. Devices suited for commercial use have just started to be developed. http: //2. imimg. com/data 2/GK/EX/MY-920622/micro-biological-testing-250 x 250. jpg http: //www. lionixbv. nl/technology-microfluidics. html

Digital Microfluidic Devices Electro-wetting Cross-section view of Digital Microfluidic device. Dotted line indicates the shape of the meniscus before actuation. Modified from [2] ● Array of electrodes which use the electrowetting effect to manipulate droplets. “Top view of flow on a ring structure” [3]

Voice of the Customer

Voice of the Customer

Functional Decomposition Much room for creativity Little to no room for creativity Medium amt. of room for creativity

Project Breakdown • • • Control System Fluid Delivery System Fabrication Automation User Interface Packaging

Control System - Specs and Metrics Problem: Can an Arduino board be used to control a DMF device to the same or better accuracy as a NI PXI control system? What Do We Need? • • • Generate a sine wave Amplify the wave to a large voltage (~90 -110 Vrms) Measure capacitance with a good resolution (~0. 2 p. F) Complete the protocol quickly (~30 min) Move/Merge droplets quickly (~100 ms) Split droplets quickly (~500 ms) What Do We Know? • Benchmark: Dr. Schertzer completed these protocols at the University of Toronto using a National Instruments (NI) control system, a signal generator, and an amplifier

Control System - Potential Concepts Benchmark - Control System used in Schertzer et al 1. NI PXI System a. Signal Generator i. Voltage: 10 Vp-p ii. Frequency: 10 k. Hz b. Controller c. Matrix-Switching Device (4 inputs / 32 outputs) 2. Agilent 4288 A Capacitance Meter a. Resolution to ~0. 20 p. F 3. Custom Amplifier a. Voltage: 90 -110 Vrms

Control System - Potential Concepts Arduino Dropbot System in Fobel et al Control Board Signal Generator Board - Generates a sine wave - Controls is a shield for the Arduino Microcontroller Switching Board • • • Voltage: up to 20 Vp-p Frequency: (0. 1 -50)k. Hz Trek Model PZD 700 A High Voltage Amplifier Arduino is open source o firmware o pin mapping o board schematics Ki. CAD Hardware designs available for Board designs 320 independent channels and is highly modular - Droplet was found to completely cover an electrode in 200 ms • • Input Voltage: 0 to ± 10 VDC Output Voltage: 0 to ± 700 VDC

Control System - Potential Concepts Arduino Dropbot System in Fobel et al Arduino Mega 2560 Microcontroller - Controls Signal Generator Board, High Voltage Switching Board - Can estimate drop position, velocity - Software Available: ● Arduino firmware ● C++ Software ● Microdrop Plugin • • • Arduino is open source o firmware o pin mapping o board schematics Ki. CAD Hardware designs available for Board designs 320 independent channels and is highly modular

Control System - Feasibility Potential Staffing Needed ● Mechanical Engineering ● Electrical Engineering ● Software Engineering ● Computer Engineering ● ● ● The Arduino Dropbot system used in Fobel et al paper was able to instantaneously measure droplet velocity, capacitance, and impedance in real time. Arduino has: a. Software: C++ software, Open source firmware b. Hardware: Microcontroller with board schematics, and pin mapping Dropbot has: a. Software: Open source firmware, Microdrop Plugin b. Hardware: Ki. CAD models to create the boards

Fluid Delivery System-HOQ

Fluid Delivery System-Specs and Metrics Problem: Is there a specific delivery system so that the desired volume of fluid can be extracted within the desired time? What We Need Droplet to be extracted between. 5 s and 5 s. Droplet Volume must be within 3% error of desired volume. What We Know Conventional Biological Protocols have been using pipettes and Syringes Duke University have used Reservoirs in their DMF Devices. • •

Fluid Delivery System-Concepts • • • Syringe o . 55 L ±. 028 Pipette o 1µL ± 4% Reservoir o Volume from User Input Plug-in Canister o Desired Volume can be extracted Combination of These

Fluid Delivery System- Feasibility • • Solutions o Reservoir system will allow us to easily dispense the fluids to the DMF device. § Using together with Pipettes will allow us to accurately dispense the desired droplet volume. o Plug-in Canister can be programmed to dispense the right amount while easily detachable and portable. Staffing Required: Students in the Mechanical Engineering discipline o Students in the Industrial Engineering discipline o

Fabrication- HOQ [10]

Fabrication: Potential Concepts Common Techniques: Photolithography and wet or dry etching (clean room) Solutions outside the clean room: PDMS stamp used to transfer a pattern onto a gold surface Desktop laser printer pattern transfer: directly onto sheet of polyimide Permanent marker electrode array outline Dielectric: Saran wrap Hydrophobic coating: Rain-X • • •

Fabrication: Feasibility Microcontact printing (micro. CP) [7] • • PDMS stamp used to deposit patterns of self assembled monolayers onto a substrate device capable of full range of operations: dispensing, merging, motion and splitting Formed from circuit board substrates and gold compact disks using rapid marker masking [8] ● procedure capable of producing devices with 50 -60 μm spacing between actuating electrodes ● saran wrap used a removable dielectric coating ● rain-x: hydrophobic coating ● able to move merge and split 1 -12 μL droplets Desktop Laser Printer Pattern transfer [9] Droplet motion: comparable to performance on chips made by photolithography ultrarapid: 80 chips in 10 mins • •

Automation - HOQ

Automation - Specs and Metrics Problem: Can a protocol be automated using existing computing methods and hardware? What Do We Need? • • • Data Storage (~0. 5 GB) Send Signal Receive Signals Processor (>10 k. Hz, ~0. 5 GB) Motion Planning What Do We Know? • Many algorithm based computing solutions already exist, just must be tailored for this specific application

Automation - Potential Concepts How to compute: • • • Existing computer On-board processor Open-source system Function: • • • Inputs: state of each electrode, protocol Process: compute necessary move, merge, mix & split instructions for a specified protocol Outputs: signals to activate control system switches, error signal to the user interface, result

Automation - Feasibility Needed Features: Available Solutions: Data Storage Memory Card, HD, SSD, Peripheral networking, ROM cartridge Send Signals Analog signals, digital signals Receive Signals Many ways to process signals. . Processor Micro-processor, multi-core processor Motion Planning Grid based algorithm, Sampling based algorithm Each feature has many well known solutions. This project is determined to be feasible.

User Interface HOQ

User Interface - Potential Concepts Lab. VIEW Front Panel [4] -Computer program w/ visual display (i. e. Lab. VIEW VI) -Touchpad -Manual input (i. e. turn dials) -Remote communication (i. e. email) Example of “lab on a chip” [5] -LED indicators -Combination of these Handheld DMF device [6]

User Interface - Feasibility Technical Feasibility -Concepts for the user interface exist in many forms -Many existing DMF devices are able to accept instructions and output results via a user interface. -Example: RIT currently uses Lab. VIEW interface provided by National Instruments Staffing Requirements A few IE, ME, and EE students, possibly a CE as well

Packaging HOQ

Packaging-Concepts Minimizing Evaporation Humidity sensing/control • • • o Humidifier/hygrometer/controls Temperature sensing/control o Refrigerator/thermometer/controls Hybrid

Packaging-Feasibility Verify that size and weight constraints are met: Staff required: Several ME students, several EE students, possibly IE students

Questions/Areas of Uncertainty • How will environmental controls be implemented? • Chip form factor?

Next Steps • Confirm ER’s • Continue to refine HOQs • Examine resource and staffing requirements • Begin PRP development

References • • • [1] Mark, D. , Haeberle, S. , Roth, G. , Von Stetten, F. , and Zengerle, R. , 2010, "Microfluidic Lab-on-a. Chip Platforms: Requirements, Characteristics and Applications, " Chemical Society Reviews, 39(3), pp. 1153 -1182. [2] Cho, S. K. , Moon, H. J. , and Kim, C. J. , 2003, "Creating, Transporting, Cutting, and Merging Liquid Droplets by Electrowetting-Based Actuation for Digital Microfluidic Circuits, " Journal of Microelectromechanical Systems, 12(1), pp. 70 -80. [3] Fair, R. , The Electrowetting Effect (in Air), February 1, http: //microfluidics. ee. duke. edu/ [4] http: //www. mstarlabs. com/software/labview. html [5] http: //www. inc. com/magazine/201111/innovation-a-blood-test- on-a-chip. html [6] http: //doktori. bme. hu/bme_palyazat/2011/tudomanyos_muhely/ szenzorlabor_en. htm [7] Watson, Michael W. L. , Mohamed Abdelgawad, George Ye, Neal Yonson, Justin Trottier, and Aaron R. Wheeler. "Microcontact Printing-Based Fabrication of Digital Microfluidic Devices. " Analytical Chemistry 78. 22 (2006): 7877 -885. Print. [8] Abdelgawad, Mohamed, and Aaron R. Wheeler. "Low-cost, Rapid-prototyping of Digital Microfluidics Devices. " Microfluidics and Nanofluidics 4. 4 (2008): 349 -55. Print. [9] Abdelgawad, M. , and A.  R. Wheeler. "Rapid Prototyping in Copper Substrates for Digital Microfluidics. " Advanced Materials 19. 1 (2007): 133 -37. Print. [10] Schertzer, M. J. , R. Ben-Mrad, and Pierre E. Sullivan. "Mechanical Filtration of Particles in Electrowetting on Dielectric Devices. " Journal of Microelectromechanical Systems 20. 4 (2011): 1010015. Print.

End Questions?