Microfluidic sedimentation system for separation of plasma from whole blood

A microfluidic system for a portable and speedy blood test device has been developed. In the system, blood is injected into a cylindrical channel with a diameter of 3.0 mm and a height of 3.0 mm from the bottom to the top. When the blood ascends the channel, blood cells sediment at the bottom and plasma is separated at the top. This system can be manufactured easily at a low cost by simply bonding two identical polydimethylsiloxane chips. Pure plasma can be obtained successfully from a very tiny amount of blood, less than a drop (9 μL).