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System Integration - A Major Step toward Lab on a Chip.

Sin ML, Gao J, Liao JC, Wong PK - J Biol Eng (2011)

Bottom Line: It is increasingly realized that an effective system integration strategy that is low cost and broadly applicable to various biological engineering situations is required to fully realize the potential of microfluidics.In this article, we review several promising system integration approaches for microfluidics and discuss their advantages, limitations, and applications.Future advancements of these microfluidic strategies will lead toward translational lab-on-a-chip systems for a wide spectrum of biological engineering applications.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ 85721, USA. pak@email.arizona.edu.

ABSTRACT
Microfluidics holds great promise to revolutionize various areas of biological engineering, such as single cell analysis, environmental monitoring, regenerative medicine, and point-of-care diagnostics. Despite the fact that intensive efforts have been devoted into the field in the past decades, microfluidics has not yet been adopted widely. It is increasingly realized that an effective system integration strategy that is low cost and broadly applicable to various biological engineering situations is required to fully realize the potential of microfluidics. In this article, we review several promising system integration approaches for microfluidics and discuss their advantages, limitations, and applications. Future advancements of these microfluidic strategies will lead toward translational lab-on-a-chip systems for a wide spectrum of biological engineering applications.

No MeSH data available.


Microfluidics paper based platform. (A) Schematics of a microfluidic paper-based analytical device which can detect glucose and protein in urine simultaneously [71]. (B) Urine sample in a paper-based microfluidic device fabricated by photolithography [71]. (C) Image of a 384-zone paper plate produced with photolithography after applying a range of volumes (1-10 μL) of solutions of different dyes [60]. It shows the fluid isolation abilities of the zones although two zones in the fifth and sixth rows show small breaches in the hydrophobic walls. (D) A 3D microfluidic paper-based analytical device with four channels located at different plates without mixing their contents [56]. (E) Cross-section view of the device in (D) [56].
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Figure 2: Microfluidics paper based platform. (A) Schematics of a microfluidic paper-based analytical device which can detect glucose and protein in urine simultaneously [71]. (B) Urine sample in a paper-based microfluidic device fabricated by photolithography [71]. (C) Image of a 384-zone paper plate produced with photolithography after applying a range of volumes (1-10 μL) of solutions of different dyes [60]. It shows the fluid isolation abilities of the zones although two zones in the fifth and sixth rows show small breaches in the hydrophobic walls. (D) A 3D microfluidic paper-based analytical device with four channels located at different plates without mixing their contents [56]. (E) Cross-section view of the device in (D) [56].

Mentions: Paper-based microfluidics have been demonstrated in recent years [56]. These diagnostic devices are made of paper, which can act as the channel and physical filter for samples and reagents. The devices are usually fabricated by patterning a paper with spatial hydrophobic barriers such that the bounded regions become the hydrophilic channels (Figure 2). The channels can be either left open to the atmosphere or sealed to thin polymer sheets. The channel guides the fluids through capillary action. Similar to a test stripe, the capillary action can be controlled by the characteristics of the material and the environmental conditions (e.g., temperature and relative humidity). There are a number of methods for creating hydrophobic patterns, such as photolithography [57], plasma etching [58], and wax printing [59]. In these methods, the thickness of the paper determines the height of the channel while the patterning process defines the geometry of the channel. The fabrication process is followed by saturating the test zones with assay reagents using manual spotting or inkjet printing. The reagents in the device should be functional after they are fully dry. Most of the diagnostic analyses on paper-based microfluidics are based on colorimetric assays and the quantitative measurement can be achieved by reflectance detection [56]. In reflectance detection, the concentration of the analyte is related to the amount of light reflected from the surface of the test zone that can be captured by a desktop scanner or digital camera. Elaborate designs for more diverse applications have been created based on paper-based microfluidics. By patterning the paper into an array of circular test zones, such as 96-zone plates or 384-zone plates, high throughput assays can be accomplished providing an alternative to conventional microplates [60] (Figure 2d). Furthermore, 3D paper-based microfluidics have been developed by stacking layers of paper-based microfluidic devices with double-sided adhesive tape patterned with fluidic connections [61]. With the 3D networks of channels, multiple operational units can be combined into a single device [48] (Figure 2d and 2e). Existing microfluidic designs, such as the H-filter [62] and T-sensor [63], can be incorporated in the paper networks without pumping or pneumatic control systems [64].


System Integration - A Major Step toward Lab on a Chip.

Sin ML, Gao J, Liao JC, Wong PK - J Biol Eng (2011)

Microfluidics paper based platform. (A) Schematics of a microfluidic paper-based analytical device which can detect glucose and protein in urine simultaneously [71]. (B) Urine sample in a paper-based microfluidic device fabricated by photolithography [71]. (C) Image of a 384-zone paper plate produced with photolithography after applying a range of volumes (1-10 μL) of solutions of different dyes [60]. It shows the fluid isolation abilities of the zones although two zones in the fifth and sixth rows show small breaches in the hydrophobic walls. (D) A 3D microfluidic paper-based analytical device with four channels located at different plates without mixing their contents [56]. (E) Cross-section view of the device in (D) [56].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3117764&req=5

Figure 2: Microfluidics paper based platform. (A) Schematics of a microfluidic paper-based analytical device which can detect glucose and protein in urine simultaneously [71]. (B) Urine sample in a paper-based microfluidic device fabricated by photolithography [71]. (C) Image of a 384-zone paper plate produced with photolithography after applying a range of volumes (1-10 μL) of solutions of different dyes [60]. It shows the fluid isolation abilities of the zones although two zones in the fifth and sixth rows show small breaches in the hydrophobic walls. (D) A 3D microfluidic paper-based analytical device with four channels located at different plates without mixing their contents [56]. (E) Cross-section view of the device in (D) [56].
Mentions: Paper-based microfluidics have been demonstrated in recent years [56]. These diagnostic devices are made of paper, which can act as the channel and physical filter for samples and reagents. The devices are usually fabricated by patterning a paper with spatial hydrophobic barriers such that the bounded regions become the hydrophilic channels (Figure 2). The channels can be either left open to the atmosphere or sealed to thin polymer sheets. The channel guides the fluids through capillary action. Similar to a test stripe, the capillary action can be controlled by the characteristics of the material and the environmental conditions (e.g., temperature and relative humidity). There are a number of methods for creating hydrophobic patterns, such as photolithography [57], plasma etching [58], and wax printing [59]. In these methods, the thickness of the paper determines the height of the channel while the patterning process defines the geometry of the channel. The fabrication process is followed by saturating the test zones with assay reagents using manual spotting or inkjet printing. The reagents in the device should be functional after they are fully dry. Most of the diagnostic analyses on paper-based microfluidics are based on colorimetric assays and the quantitative measurement can be achieved by reflectance detection [56]. In reflectance detection, the concentration of the analyte is related to the amount of light reflected from the surface of the test zone that can be captured by a desktop scanner or digital camera. Elaborate designs for more diverse applications have been created based on paper-based microfluidics. By patterning the paper into an array of circular test zones, such as 96-zone plates or 384-zone plates, high throughput assays can be accomplished providing an alternative to conventional microplates [60] (Figure 2d). Furthermore, 3D paper-based microfluidics have been developed by stacking layers of paper-based microfluidic devices with double-sided adhesive tape patterned with fluidic connections [61]. With the 3D networks of channels, multiple operational units can be combined into a single device [48] (Figure 2d and 2e). Existing microfluidic designs, such as the H-filter [62] and T-sensor [63], can be incorporated in the paper networks without pumping or pneumatic control systems [64].

Bottom Line: It is increasingly realized that an effective system integration strategy that is low cost and broadly applicable to various biological engineering situations is required to fully realize the potential of microfluidics.In this article, we review several promising system integration approaches for microfluidics and discuss their advantages, limitations, and applications.Future advancements of these microfluidic strategies will lead toward translational lab-on-a-chip systems for a wide spectrum of biological engineering applications.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ 85721, USA. pak@email.arizona.edu.

ABSTRACT
Microfluidics holds great promise to revolutionize various areas of biological engineering, such as single cell analysis, environmental monitoring, regenerative medicine, and point-of-care diagnostics. Despite the fact that intensive efforts have been devoted into the field in the past decades, microfluidics has not yet been adopted widely. It is increasingly realized that an effective system integration strategy that is low cost and broadly applicable to various biological engineering situations is required to fully realize the potential of microfluidics. In this article, we review several promising system integration approaches for microfluidics and discuss their advantages, limitations, and applications. Future advancements of these microfluidic strategies will lead toward translational lab-on-a-chip systems for a wide spectrum of biological engineering applications.

No MeSH data available.