Microfluidics geometries involved in effective blood plasma separation

Abstract

The last two decades witnessed a significant advancement in the field of diluted and whole blood plasma separation. This is one of the common procedures used to diagnose, cure and treat numerous acute and chronic diseases. For this separation purpose, various types of geometries of microfluidic devices, such as T-channel, Y-channel, trifurcation, constriction–expansion, curved/bend/spiral channels, a combination of any of the two geometries, etc., are being exploited, and this is detailed in this review article. The evaluation of the performance of such devices is based on the several parameters such as separation efficiency, flow rate, hematocrits, channel dimensions, etc. Thus, the current extensive review article endeavours to understand how particular geometry influences the separation efficiency for a given hematocrit. Additionally, a comparative analysis of various geometries is presented to demonstrate the less explored geometric configuration for the diluted and whole blood plasma separation. Also, a meta-analysis has been performed to highlight which geometry serves best to give a consistent separation efficiency. This article also presents tabulated data for various geometries with necessary details required from a designer’s perspective such as channel dimensions, targeted component, studied range of hematocrit and flow rate, separation efficiency, etc. The maximum separation efficiency that can be achieved for a given hematocrits and geometry has also been plotted. The current review highlights the critical findings relevant to this field, state of the art understanding and the future challenges.

Sample-to-answer lateral flow assay with integrated plasma separation and NT-proBNP detection

“…Firstly, expensive and cumbersome bench-top instruments are required, hindering the application in low-resource settings [16]. Secondly, the device involves sophisticated geometric structures [17], posing a challenge in achieving consistent fabrication and hindering the scalability process [18]. Thirdly, these techniques exhibit limited efficiency in separating plasma from high hematocrit samples, necessitating off-chip dilution of whole blood before analysis, thereby introducing cost and complexity to the procedure and diluting the target analyte, which presents a challenge in precisely detecting such minimal levels of analytes, especially when working with small finger prick volumes [19][20][21].…”