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Published on: May 15, 2017
Transmittance tuning by particle chain polarization in electrowetting-driven droplets
Shih-Kang Fan1, Cheng-Pu Chiu, Po-Wen Huang
1Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan.
Biomicrofluidics
|January 27, 2011
Summary
Microfluidic droplets with nanoparticles act as optical components. Electrowetting-on-dielectric (EWOD) and particle polarization enable tunable transmittance for micro-opto-fluidic systems.
Area of Science:
- Microfluidics
- Optics
- Nanotechnology
Background:
- Digital microfluidic lab-on-a-chip systems often handle nano/microparticle suspensions.
- Droplets containing these particles can function as micro-optical components.
- Tunable optical properties are desirable for micro-opto-fluidic applications.
Purpose of the Study:
- To demonstrate tunable transmittance of microfluidic droplets containing nano/microparticles.
- To utilize electrowetting-on-dielectric (EWOD) and particle chain polarization for optical control.
- To investigate the application of these principles in micro-opto-fluidic systems.
Main Methods:
- Utilized electrowetting-on-dielectric (EWOD) for millimeter-scale droplet manipulation.
- Employed particle chain polarization for micrometer-scale particle manipulation.
- Designed and fabricated parallel plate devices to selectively apply electric fields at different frequencies.
- Applied electric fields at low frequencies for EWOD-driven droplet pumping.
- Applied electric fields at high frequencies to induce particle polarization and chain formation.
Main Results:
- Achieved selective manipulation of droplets and suspended particles using frequency-controlled electric fields.
- Demonstrated "dark" or reflective droplets at low frequencies due to dispersed particles.
- Showcased "bright" or transmissive droplets at high frequencies due to particle chain formation increasing transmittance.
- Measured droplet reflectance across various frequencies and amplitudes.
Conclusions:
- Microfluidic droplets with nano/microparticles can serve as programmable micro-optical components.
- Cross-scale electric field manipulation (EWOD and particle polarization) allows for tunable droplet transmittance.
- This technique offers a novel approach for advanced micro-opto-fluidic systems.
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