Integration and Scalable Manufacturing of Printed Microfluidic Devices Jeffrey Morse, Aditi Naik, Yiliang Zhou, David Gonzalez, Brenda Warren, Uzodinma Okoroanyanwu and James J. Watkins University of Massachusetts, Amherst, MA Azar Alizadeh, Nandini Nagraj, Ralf Lenigk, Andrew Burns GE Global Research, Niskayuna NY 12309 FLEX 2017 June 20-22, 2017 Monterey, CA
Outline Background: Potential Biomarker Targets Flexible Microfluidics Platform Concept for Monitoring Biomarkers in Sweat Printed Electrowetting Valves Printed Microfluidics Glucose Sensing
Background Courtesy of R. Naik, AFRL
Courtesy of R. Naik, AFRL
Background: Orexin A Sensor Courtesy of R. Naik, AFRL
Integrated Microfluidic Sensor Concept for Monitoring Biomarkers in Sweat Electrowetting Valve Sensor Evaporation Skin Interface Absorbing paper Wicking paper Sweat flow Pros: Low cost of printing Simple integration schemes Cons/Challenges: EW Valve reversibility Single use sensors due to irreversibility of the valves Potentially long retention times
Challenge: Scalable Printing and Integration of Microfluidic System Components Sensor element; Power supply; Microchip; Microfluidics; RFID Direct Printing Technologies Image copyright: General Electric. Inkjet printing Screen printing Direct laser writing
Printed Microfluidic Electrodes: Inkjet-Printed Silver Pattern / Photonic Sintering Photonic sintering Optimized conditions: 420V, 5000us, 12uP, 6x, 25% duty Resistance ~ 5Ω Prototype Production
Printed Electrowetting Valves for Microfluidic Control and Sample Acquisition Capillary flow microfluidics Modified Ag electrodes PFDT: Low voltage to actuate Flexible microfluidic device T. Mérian et al. Colloids and Surfaces A: Physicochem. Eng. Aspects 414 (2012) 251 258
Paperfluidic Valves Functioning a) Fluid flow is stopped at Ag hydrophobic electrode/valve b) 16V is applied: monolayer disrupted c) Valve is actuated, allowing fluid to flow d) Continuation of fluid flow
Imprint Patterning of Complex Microfluidic Architectures UV-Assisted: Contact UV-curable resin with master, photocure
Fully Printed Microfluidic Sensing Device Platform Integration of functional subcomponents in single process platform
Integrated Sweat Sensing Device Demonstration of functional subcomponents in single platform -Absorbent paper pad interfaced to capillary printed microfluidic channels -Printed EW valve for on demand fluidic control -Electrochemical detection of hydroquinone in solution Nugen, Watkins, Carter, et. al., Lab-on-a-Chip 2015
Enzymatic Glucose Sensor GOx can be immobilized on to the CeO 2 by the electrostatic interaction at ph ~7 Isoelectric point (IEP): CeO 2 ~9 ZnO 9.5 GOx 4.2 Catalysts 2017, 7, 31 Sensors 2010, 10(5), 4855-4886
Direct Printing of High Surface Area Metal Oxide Sensors by NanoImprint Lithography Versatile materials, compatible with flexible and organic substrates
Preliminary Glucose Sensor Data V P t Calibration curves for glucose (in potassium phosphate buffer, 50 mm, ph 7.5, 25 0 C, -0.7 V). Error bars shows the standard deviation of three measurements.
Calibration Results for CeO 2 Tetralayer Sensor (a) Calibration curves for glucose (with range of 0.2 mm to 1.0 mm in potassium phosphate buffer, 50 mm, ph 7.0, 25 0 C, -0.7 V). Error bars shows the standard deviation of three measurements. (b) Amperometric response curve of the fabricated tetralayer CeO 2 sensor with successive glucose injection. The potential was set at -0.7 V.
Electrochemical Impedance Spectroscopy (EIS) Measurements Printed Au Interdigitated Electrodes Cortisol Detection Demonstrated Equivalent circuit C R R p R p Calibrate R p to Cortisol Concentration -determine LOD
Summary Emerging needs for wearable human monitoring sensor platforms Enabled by scalable processes for printed microfluidics Integration of microfluidic control elements allow sample acquisition on demand Printed sensors functionalized for specific biomarker detection Eventual integration with silicon control electronics and other biometric sensors serve a range of applications Healthcare, activity monitoring, etc.