On-Chip Double Emulsion Droplet Assembly Using Electrowetting-on-Dielectric and Dielectrophoresis

Electrowetting-on-dielectric (EWOD) based droplet actuation in microfluidic chip is designed and fabricated. EWOD is used as on-chip micro-pumping scheme for moving fluid digitally in Lab-on-a-chip devices. For enabling this scheme, stacked deposition of thin dielectric and hydrophobic layer in that order between microchannel and electrodes is done. The present paper investigates the potential use of SU-8 as hydrophobic layer in conjunction of acting as dielectric in the device. The objective for the investigation is to lower the cost and a thin simplification in fabrication process of EWOD-based devices. We have done design and optimization of dimensions of electrode array including gap between arrays for EWOD micropump. Design and optimization are carried out in CoventorWare. The designing is followed by fabrication of device and analysis for droplet motion. The fabrication of the device includes array of electrodes over the silicon surface and embedding them in hydrophobic SU-8 layer. Water droplet movement in the order of microliter of spherical shape is demonstrated. It has been shown that an SU-8 microchannel in the current design allows microfluidic flow at tens of voltages comparable with costlier and more complicated to fabricate designs reported in the literature.

Download Full-text

On-chip thermo-triggered coalescence of controllable Pickering emulsion droplet pairs

RSC Advances ◽

10.1039/c6ra12594h ◽

2016 ◽

Vol 6 (69) ◽

pp. 64182-64192 ◽

Cited By ~ 16

Author(s):

Jian Sun ◽

Wei Wang ◽

Fan He ◽

Zhi-Hao Chen ◽

Rui Xie ◽

...

Keyword(s):

Pickering Emulsion ◽

Emulsion Droplet ◽

One To One ◽

On Chip

Continuous thermo-triggered one-to-one coalescence of controllable Pickering emulsion droplet pairs, is successfully achieved in microchannels and provides a novel mode for droplet-based microreactors and microdetectors.

Download Full-text

Active Hot Spot Cooling Controlled by Single-Sided Electrowetting-on-Dielectric (SEWOD)

Volume 2: Heat Transfer Enhancement for Practical Applications; Fire and Combustion; Multi-Phase Systems; Heat Transfer in Electronic Equipment; Low Temperature Heat Transfer; Computational Heat Transfer ◽

10.1115/ht2012-58111 ◽

2012 ◽

Cited By ~ 1

Author(s):

Sung-Yong Park ◽

Jiangtao Cheng ◽

Chung-Lung (C.-L. ) Chen

Keyword(s):

Heat Transfer ◽

Fluid Transport ◽

Hot Spot ◽

Two Phase ◽

Electrowetting On Dielectric ◽

Transfer Capability ◽

Heat Transfer Capability ◽

Spot Cooling ◽

On Chip ◽

Two Phase Cooling

Electrowetting-on-dielectric (EWOD) has attracted as one of the effective on-chip cooling technologies. It enables rapid transport of coolant droplets and heat transfer from target heat sources, while consuming extremely low power for fluid transport. However, a sandwiched configuration in conventional EWOD devices only allows sensible heat transfer, which very limits heat transfer capability of the device. In this paper, we report a novel single-sided EWOD (SEWOD) technology that enables two-phase cooling on a single-sided plate. As a result, heat transfer capability of the SEWOD device can be significantly enhanced. A complete set of droplet manipulation functions necessary for active hot spot cooling has been achieved on SEWOD. Hot spot surface modification to hydrophilic makes a droplet stick on a hot spot and maximize its contact area, greatly improving thermal rejection capability of the device. We have demonstrated two-phase cooling on SEWOD. With successive transportation of four droplets with a volume of 30 μL, the hot spot temperature that was initially heated up to 172°C was able to be stably maintained below 100 °C for 475s. This novel SEWOD-driven cooling technique promises to potentially function as a wickless vapor chamber with enhanced thermal managing capabilities.

Download Full-text

Multimodal breakup of a double emulsion droplet under an electric field

Soft Matter ◽

10.1039/c8sm02230e ◽

2019 ◽

Vol 15 (10) ◽

pp. 2292-2300 ◽

Cited By ~ 10

Author(s):

Muhammad Salman Abbasi ◽

Ryungeun Song ◽

Hyoungsoo Kim ◽

Jinkee Lee

Keyword(s):

Electric Field ◽

Direct Current ◽

Double Emulsion ◽

Emulsion Droplet ◽

Direct Current Electric Field ◽

Current Electric Field

We study the multimodal breakup of a double emulsion droplet under a uniform direct current electric field.

Download Full-text

Hydrodynamic analysis of one deformed double emulsion droplet under shear

Journal of Dispersion Science and Technology ◽

10.1080/01932691.2021.2013864 ◽

2021 ◽

pp. 1-11

Author(s):

Chengyao Wang ◽

Chen Zhao ◽

Fei Xu

Keyword(s):

Double Emulsion ◽

Emulsion Droplet ◽

Hydrodynamic Analysis

Download Full-text

Interfacing Digital Microfluidics with Ambient Mass Spectrometry Using SU-8 as Dielectric Layer

Micromachines ◽

10.3390/mi9120649 ◽

2018 ◽

Vol 9 (12) ◽

pp. 649 ◽

Cited By ~ 5

Author(s):

Gowtham Sathyanarayanan ◽

Markus Haapala ◽

Tiina Sikanen

Keyword(s):

Mass Spectrometry ◽

Dielectric Layer ◽

Digital Microfluidics ◽

Drug Distribution ◽

Substrate Material ◽

Ambient Mass Spectrometry ◽

Electrowetting On Dielectric ◽

On Chip ◽

Ambient Ms ◽

Digital Microfluidic

This work describes the interfacing of electrowetting-on-dielectric based digital microfluidic (DMF) sample preparation devices with ambient mass spectrometry (MS) via desorption atmospheric pressure photoionization (DAPPI). The DMF droplet manipulation technique was adopted to facilitate drug distribution and metabolism assays in droplet scale, while ambient mass spectrometry (MS) was exploited for the analysis of dried samples directly on the surface of the DMF device. Although ambient MS is well-established for bio- and forensic analyses directly on surfaces, its interfacing with DMF is scarce and requires careful optimization of the surface-sensitive processes, such as sample precipitation and the subsequent desorption/ionization. These technical challenges were addressed and resolved in this study by making use of the high mechanical, thermal, and chemical stability of SU-8. In our assay design, SU-8 served as the dielectric layer for DMF as well as the substrate material for DAPPI-MS. The feasibility of SU-8 based DMF devices for DAPPI-MS was demonstrated in the analysis of selected pharmaceuticals following on-chip liquid-liquid extraction or an enzymatic dealkylation reaction. The lower limits of detection were in the range of 1–10 pmol per droplet (0.25–1.0 µg/mL) for all pharmaceuticals tested.

Download Full-text