Surface molecular property modification for poly(dimethylsoloxane) (PDMS) based microfluidic devices. Microfluid Nanofluid 7:291-306

Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, USA, .
Microfluidics and Nanofluidics (Impact Factor: 2.53). 09/2009; 7(3):291-306. DOI: 10.1007/s10404-009-0443-4
Source: PubMed

ABSTRACT Fast advancements of microfabrication processes in past two decades have reached to a fairly matured stage that we can manufacture a wide range of microfluidic devices. At present, the main challenge is the control of nanoscale properties on the surface of lab-on-a-chip to satisfy the need for biomedical applications. For example, poly(dimethylsiloxane) (PDMS) is a commonly used material for microfluidic circuitry, yet the hydrophobic nature of PDMS surface suffers serious nonspecific protein adsorption. Thus the current major efforts are focused on surface molecular property treatments for satisfying specific needs in handling macro functional molecules. Reviewing surface modifications of all types of materials used in microfluidics will be too broad. This review will only summarize recent advances in nonbiofouling PDMS surface modification strategies applicable to microfluidic technology and classify them into two main categories: (1) physical approach including physisorption of charged or amphiphilic polymers and copolymers, as well as (2) chemical approach including self assembled monolayer and thick polymer coating. Pros and cons of a collection of available yet fully exploited surface modification methods are briefly compared among subcategories.

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    Sensors and Actuators B Chemical 07/2015; 220:1320-1327. DOI:10.1016/j.snb.2015.07.024 · 4.10 Impact Factor
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    Microfluidics and Nanofluidics 02/2015; DOI:10.1007/s10404-015-1568-2 · 2.53 Impact Factor
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    • "Several groups have previously used PLGA–PEG block copolymers to prepare nanoparticles using 2D hydrodynamic flow focusing on microfluidic channels (Karnik et al. 2008; Valencia et al. 2010), in which the polymer stream in acetonitrile was horizontally focused by water sheath streams. However, the adsorption of the hydrophobic polymer onto the surface of mcirofluidic channel (Wu et al. 2005; Wong and Ho 2009) causes aggregation of polymer nanoparticles with high molecular weight or high concentration, which may lead to increased internal pressure in the microfluidic channels, resulting in irreversible failure of device and lack of robustness of operation. A better approach to prevent the nanoparticles from aggregation on the PDMS walls and clogging in the microchannels is the 3D hydrodynamic flow focusing technique, in which the polymer stream was both horizontally and vertically focused. "
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