Abstract
A bidirectional annular microfluidic mixing chip comprises an active layer, a mixing layer and a substrate vertically stacking on one another. The active layer comprises an inflation loop channel having a plurality of gas chambers which are arranged in order of increasing size and are deformable subjected to press down by gas inflation. The mixing layer has a mixing loop channel corresponding to the inflation loop channel and two runners connected to the mixing loop channel for fluid injection. When fluid enters the mixing loop channel via the runners, gas can be introduced from the exterior to inflate the gas chamber and deform the gas chambers such that the mixing loop channel is squeezed. Fluid in the mixing loop channel is squeezed and therefore mixed and flows therein. Thus, gas chambers with different sizes can be deformed downward when squeezed so as to provide the fluid mixing and perturbation functions for quickly and uniformly mixing the fluid.