Developing a novel continuum model of static and dynamic contact angles in a case study of a water droplet on micro-patterned hybrid substrates

Azimi, Arash; He, Ping; Rohrs, Chae; Yao, Chun-Wei

doi:10.1557/mrc.2018.215

Cited by 7 publications

(1 citation statement)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the one hand, the roughness and geometry of the microchannel have a certain impact on the liquid flow, for example, Kasiteropoulou et al [6] used numerical methods to deeply study the impact of wall roughness on the fluid flow and found that near the rough wall, the fluid particles tend to be trapped in the wall cavity, and the flow rate will decrease with the narrowing of the channel. Arash et al [7] also used numerical methods to study how a water droplet interacts with micrometer-sized patterns of a hybrid hydro-phobic/-philic surface and revealed the details of the droplet-surface interaction. On the other hand, the hydrophilicity of microchannels also affects the flow of liquid, especially when capillary force is dominant.…”

Section: Introductionmentioning

confidence: 99%

Surface Hydrophilic Modification for Chip of Centrifugal Microfluidic Immunoassay System

Shi

Wang

et al. 2022

Micromachines

View full text Add to dashboard Cite

The surface of a centrifugal microfluidic immunoassay system chip such as polymethyl methacrylate (PMMA) is often hydrophobic, which leads to problems such as poor liquid transfer efficiency and easy-to-block siphon channels, leading to bad fluid control. Therefore, surface hydrophilic modification for such chips is necessary to improve the rapidity and sensitivity of the system. Chemical modification is commonly used, but there is little research on the hydrophilic effect of different concentrations of hydrophilic reagents. According to function requirements for different microchannels of the chip (some only need to ensure the liquid can flow into the next chamber, and some also need to ensure the function of “closing the door” during immunoassay incubation), we explored the best combination of hydrophilic reagent and concentration through experiments. Firstly, three hydrophilic reagents were used for modification. Secondly, the hydrophilic effects of different reagents and concentrations were explored by contact angle test, the influence of different modification methods on liquid transfer efficiency was characterized by residual liquid calculation in the chamber. Finally, the effect of different hydrophilic reagents on absorbance was also tested. By experimental results and comprehensively considering the stability of the modification effect and the function requirements, Tween-20 (2.0% v/v) was chosen as the modifying reagents of the first siphon valve and the second siphon valve, and TritonX-100 (2.0% v/v) was chosen for the third siphon valve, which effectively reduces the contact angle and improves the liquid transfer efficiency, leading to further improvement of the rapidity and sensitivity of the centrifugal microfluidic immunoassay system by efficient siphoning and high plasma separation efficiency (99%).

show abstract

Section: Introductionmentioning

confidence: 99%