Strategies for void-free liquid filling of micro cavities

We deal with the problem of void-free capillary filling of micro cavities. Special emphasis is given to the effect of critical edges. Analytical, numerical and experimental methods are used to examine the capillary filling of micro cavities. The advantages and disadvantages of these methods are discussed in detail. In summary, a brief theory of the capillary dynamics in critical edges is established. Strategies are introduced to conduct a design for void-free filling of microfluidic devices on the basis of critical edges and pinning barriers.