Gabriel Tomic, Pooyan Tirandazi, Carlos H. Hidrovo
Undergraduate Category: Engineering and Technology Degree Seeking: Bachelor Degree Abstract ID#1752
Multiplanar Flow – Focusing Microfluidic Device for Aerosol Generation Gabriel Tomic, Pooyan Tirandazi, Carlos H. Hidrovo Multiscale Thermal Fluids Laboratory, Northeastern University, Boston, MA
Abstract • Typical, planar, microfluidic devices utilize two immiscible liquids (most common is water in oil emulsion) to create micron sized droplets. • These microfluidic planar devices have limited performance in terms of droplet generation frequency and size of droplet diameter. • In this study, a 3-D microfluidic flow-focusing device is proposed for droplet generation using a high speed gas phase.
Fabrication • Photolithography ◦ 3 cycles with 3 different masks • Soft – Lithography
Experimental Setup Master Mold
2D Water – Oil Microfluidic device
Introduction • There are two types of devices for microfluidic droplet generation: lithography – based devices (usually made of PDMS) and capillaries. • PDMS devices, compared to capillaries, are cheaper, easier to fabricate, and incorporate on LOC (Lab on a Chip) Systems. • Typical PDMS microfluidic device is planar, where inlet and outlet channel heights are the same, and liquid – liquid flow is utilized for droplet generation. • The proposed system has non - planar architecture, where inlet and outlet channels don’t have same heights, and utilizes liquid – air flow for droplet generation. • Possible application of the newly proposed device:
2D Water – Air Microfluidic device Photolithography process
Master mold and final dimensions of channels
Soft – Lithography process
Digital Droplet PCR
Aerosol Drug Delivery
Microparticle Fabrication
Proposed 3D Water – Air Microfluidic device
Results Jetting Regime • Regime with highest droplet frequency generation and lowest droplet diameter • Droplet diameter is calculated as: Ddrop =
Flow regime map
Representation of different flow regimes: (A) Flooded, (B) Dripping, (C) Jetting
3
6QL πƒ
Experimental data for jetting regime: droplet generation frequency and droplet diameter, water flow is constant at 100μL/min
• Where QL is liquid (water) flow rate, and f is frequency of droplet generation. This equation was used to validate experimental results.
References: 1) Simonnet C, Groisman A (2005) Two-dimensional hydrodynamic focusing in a simple microfluidic device. Appl Phys Lett 87(11):114,104 2) Anderson JR, Chiu DT, Wu H, Schueller OJ, Whitesides GM (2000) Fabrication of microfluidic systems in poly (dimethylsiloxane). Electrophoresis 21:27–40 3) Nisisako T, Torii T and Higuchi T 2002 Droplet formation in a microchannel network Lab Chip 2 24–6 4) Scott R, Sethu P, Harnett CK (2008) Three-dimensional hydro- dynamic focusing in a microfluidic coulter counter. Rev Sci Instrum 79(4):046,104
Experimental data for jetting regime: droplet generation frequency and droplet diameter, air pressure is constant at 20kPa
Conclusion and Future Plans • A new flow regime map was mapped with following regimes identified: flooded, dripping, and jetting • Maximal droplet generation frequency of 120 kHz, and minimal droplet diameter of 25 μm was achieved representing significant improvement of throughput for microfluidic droplet generation devices. • Future plans involve: • Further miniaturization of the micro fluidic device to achieve higher throughput and lower droplet diameter. • Stabilization of the jet in jetting regime
Impact • The unique feature about my innovation/research is: 3D architecture of a PDMS microfluidic device • This addresses the problem of: Droplet generation frequency and size
Multiplanar Flow – Focusing Microfluidic Device for Aerosol Generation Gabriel Tomic, Pooyan Tirandazi, Carlos H. Hidrovo Multiscale Thermal Fluids Laboratory, Northeastern University, Boston, MA
Abstract • Typical, planar, microfluidic devices utilize two immiscible liquids (most common is water in oil emulsion) to create micron sized droplets. • These microfluidic planar devices have limited performance in terms of droplet generation frequency and size of droplet diameter. • In this study, a 3-D microfluidic flow-focusing device is proposed for droplet generation using a high speed gas phase.
Fabrication • Photolithography ◦ 3 cycles with 3 different masks • Soft – Lithography
Experimental Setup Master Mold
2D Water – Oil Microfluidic device
Introduction • There are two types of devices for microfluidic droplet generation: lithography – based devices (usually made of PDMS) and capillaries. • PDMS devices, compared to capillaries, are cheaper, easier to fabricate, and incorporate on LOC (Lab on a Chip) Systems. • Typical PDMS microfluidic device is planar, where inlet and outlet channel heights are the same, and liquid – liquid flow is utilized for droplet generation. • The proposed system has non - planar architecture, where inlet and outlet channels don’t have same heights, and utilizes liquid – air flow for droplet generation. • Possible application of the newly proposed device:
2D Water – Air Microfluidic device Photolithography process
Master mold and final dimensions of channels
Soft – Lithography process
Digital Droplet PCR
Aerosol Drug Delivery
Microparticle Fabrication
Proposed 3D Water – Air Microfluidic device
Results Jetting Regime • Regime with highest droplet frequency generation and lowest droplet diameter • Droplet diameter is calculated as: Ddrop =
Flow regime map
Representation of different flow regimes: (A) Flooded, (B) Dripping, (C) Jetting
3
6QL πƒ
Experimental data for jetting regime: droplet generation frequency and droplet diameter, water flow is constant at 100μL/min
• Where QL is liquid (water) flow rate, and f is frequency of droplet generation. This equation was used to validate experimental results.
References: 1) Simonnet C, Groisman A (2005) Two-dimensional hydrodynamic focusing in a simple microfluidic device. Appl Phys Lett 87(11):114,104 2) Anderson JR, Chiu DT, Wu H, Schueller OJ, Whitesides GM (2000) Fabrication of microfluidic systems in poly (dimethylsiloxane). Electrophoresis 21:27–40 3) Nisisako T, Torii T and Higuchi T 2002 Droplet formation in a microchannel network Lab Chip 2 24–6 4) Scott R, Sethu P, Harnett CK (2008) Three-dimensional hydro- dynamic focusing in a microfluidic coulter counter. Rev Sci Instrum 79(4):046,104
Experimental data for jetting regime: droplet generation frequency and droplet diameter, air pressure is constant at 20kPa
Conclusion and Future Plans • A new flow regime map was mapped with following regimes identified: flooded, dripping, and jetting • Maximal droplet generation frequency of 120 kHz, and minimal droplet diameter of 25 μm was achieved representing significant improvement of throughput for microfluidic droplet generation devices. • Future plans involve: • Further miniaturization of the micro fluidic device to achieve higher throughput and lower droplet diameter. • Stabilization of the jet in jetting regime
Impact • The unique feature about my innovation/research is: 3D architecture of a PDMS microfluidic device • This addresses the problem of: Droplet generation frequency and size
