A centrifugal Lab-in-a-tubing platform enabling automatic point-of-care blood diagnostics

Blood analyses are the most common clinical diagnostic methods. Lab-on-a-chip technology, stemmed from concepts of microsystem microfabrication and microfluidics, provides an automatic, rapid, cost-effective and point-of-care solution for a wide variety of blood analyses. In general, blood separation is the first step for subsequent blood tests in clinical diagnosis. In this study, a rapid prototyping of out-of-plane valves using low cost tygon tubing is introduced to centrifugal system. With novel design of the out-of-plane valves, such Lab-in-a-tubing centrifugal systems can easily separate raw blood into blood cells and plasma. The out-of-plane valve has shown excellent capability in preventing backflow or reverse mixing due to diffusion. In addition, using tygon tubing is an easy, robust and inexpensive means to configure 3D microchannel networks, which is a fast proof-of-concept approach for the design of Lab-on-a-chip devices. At the end, this paper also presents a photolithographic microfabrication process for mass production of 3D Lab-on-a-CD microfluidic devices.