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Nanoscale surface modifications to control capillary flow characteristics in PMMA microfluidic devices.

Mukhopadhyay S, Roy SS, D'Sa RA, Mathur A, Holmes RJ, McLaughlin JA - Nanoscale Res Lett (2011)

Bottom Line: Experimental results presented in detail the surface modifications in the form of distinct changes in the static water contact angle across a range from 44.3 to 81.2 when compared to pristine PMMA surfaces.Additionally, capillary flow of water (dyed to aid visualization) through the microfluidic devices was recorded and analyzed to provide comparison data between filling time of a microfluidic chamber and surface modification characteristics, including the effects of surface energy and surface roughness on the microfluidic flow.We have experimentally demonstrated that fluid flow and thus filling time for the microfluidic device was significantly faster for the device with surface modifications that resulted in a lower static contact angle, and also that the incorporation of micro-pillars into a fluidic device increases the filling time when compared to comparative devices.

View Article: PubMed Central - HTML - PubMed

Affiliation: Nanotechnology and Integrated Bio-Engineering Center, School of Engineering, University of Ulster, Jordanstown, Co Antrim, BT37 0QB, Northern Ireland, UK. s.sinha-roy@ulster.ac.uk.

ABSTRACT
Polymethylmethacrylate (PMMA) microfluidic devices have been fabricated using a hot embossing technique to incorporate micro-pillar features on the bottom wall of the device which when combined with either a plasma treatment or the coating of a diamond-like carbon (DLC) film presents a range of surface modification profiles. Experimental results presented in detail the surface modifications in the form of distinct changes in the static water contact angle across a range from 44.3 to 81.2 when compared to pristine PMMA surfaces. Additionally, capillary flow of water (dyed to aid visualization) through the microfluidic devices was recorded and analyzed to provide comparison data between filling time of a microfluidic chamber and surface modification characteristics, including the effects of surface energy and surface roughness on the microfluidic flow. We have experimentally demonstrated that fluid flow and thus filling time for the microfluidic device was significantly faster for the device with surface modifications that resulted in a lower static contact angle, and also that the incorporation of micro-pillars into a fluidic device increases the filling time when compared to comparative devices.

No MeSH data available.


Variation of filling time with static water contact angle.
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Figure 9: Variation of filling time with static water contact angle.

Mentions: The air-water interface position and the filling time (time required for the meniscus to travel from the inlet to outlet of the device) were determined from the video files captured using the CMOS camera. A representative sequence of frames following the meniscus movement of dyed water on the air DBD processed microchannel surface containing 300 μm pillar is shown in Figure 6. While, Figure 7 presents the meniscus position-time graphs for the device containing no pillars on the channel wall and Figure 8 presents the data for the device containing 100 μm pillars on the bottom of the microchannel. The variation in filling time as a function of contact angle is shown in Figure 9, and the following observations can be made from the data presented in Figure 7 to Figure 9:


Nanoscale surface modifications to control capillary flow characteristics in PMMA microfluidic devices.

Mukhopadhyay S, Roy SS, D'Sa RA, Mathur A, Holmes RJ, McLaughlin JA - Nanoscale Res Lett (2011)

Variation of filling time with static water contact angle.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211507&req=5

Figure 9: Variation of filling time with static water contact angle.
Mentions: The air-water interface position and the filling time (time required for the meniscus to travel from the inlet to outlet of the device) were determined from the video files captured using the CMOS camera. A representative sequence of frames following the meniscus movement of dyed water on the air DBD processed microchannel surface containing 300 μm pillar is shown in Figure 6. While, Figure 7 presents the meniscus position-time graphs for the device containing no pillars on the channel wall and Figure 8 presents the data for the device containing 100 μm pillars on the bottom of the microchannel. The variation in filling time as a function of contact angle is shown in Figure 9, and the following observations can be made from the data presented in Figure 7 to Figure 9:

Bottom Line: Experimental results presented in detail the surface modifications in the form of distinct changes in the static water contact angle across a range from 44.3 to 81.2 when compared to pristine PMMA surfaces.Additionally, capillary flow of water (dyed to aid visualization) through the microfluidic devices was recorded and analyzed to provide comparison data between filling time of a microfluidic chamber and surface modification characteristics, including the effects of surface energy and surface roughness on the microfluidic flow.We have experimentally demonstrated that fluid flow and thus filling time for the microfluidic device was significantly faster for the device with surface modifications that resulted in a lower static contact angle, and also that the incorporation of micro-pillars into a fluidic device increases the filling time when compared to comparative devices.

View Article: PubMed Central - HTML - PubMed

Affiliation: Nanotechnology and Integrated Bio-Engineering Center, School of Engineering, University of Ulster, Jordanstown, Co Antrim, BT37 0QB, Northern Ireland, UK. s.sinha-roy@ulster.ac.uk.

ABSTRACT
Polymethylmethacrylate (PMMA) microfluidic devices have been fabricated using a hot embossing technique to incorporate micro-pillar features on the bottom wall of the device which when combined with either a plasma treatment or the coating of a diamond-like carbon (DLC) film presents a range of surface modification profiles. Experimental results presented in detail the surface modifications in the form of distinct changes in the static water contact angle across a range from 44.3 to 81.2 when compared to pristine PMMA surfaces. Additionally, capillary flow of water (dyed to aid visualization) through the microfluidic devices was recorded and analyzed to provide comparison data between filling time of a microfluidic chamber and surface modification characteristics, including the effects of surface energy and surface roughness on the microfluidic flow. We have experimentally demonstrated that fluid flow and thus filling time for the microfluidic device was significantly faster for the device with surface modifications that resulted in a lower static contact angle, and also that the incorporation of micro-pillars into a fluidic device increases the filling time when compared to comparative devices.

No MeSH data available.