Fingernail sized centrifuge for blood plasma
Scientists led by Leslie Yeo from Monash University in Clayton, Australia, have developed a miniature centrifuge for separating blood plasma and blood cells. Using an electrode, they blew a weak ionic wind over a liquid in such a way that it began to rotate like a whirlpool. Like the leaves stirring tea in a cup, the red blood cells then pooled in the center of the cylindrical chamber while the plasma was pushed to the rim. In about seven minutes, Yeo and his colleagues separated the blood in a chamber eight millimeters in diameter.
The core of your centrifuge is the needle-shaped, inclined electrode. When energized, it ionizes the air around its tip, repelling oppositely charged air particles. A so-called ion wind is then created together with entrained non-ionised particles.
The background to the development are attempts to automatically analyze blood samples in "laboratories" the size of a credit card. All previous approaches, including generating the plasma itself on the chip, were based on error-prone moving parts or membranes. With Yeo's method, only the electrode needs to be supplied with electricity. The researchers estimate that their centrifuge could be ready for use in five to ten years.
