Novel Designs of Herringbone Chaotic Mixers

In this work, we present novel designs of herringbone-type chaotic mixers which can effectively induce more transverse movement of flows and thus increase mixing performance. The original design of the herringbone-type chaotic mixer was proposed by Stroock et al. The major advantages of the chaotic mixer are the simplicities in device fabrication (i.e., simple geometry) and operation (i.e., passive device), as well as relatively short required mixing lengths. However, because the mixer of this type is a passive device, it still needs relatively long mixing lengths (e.g., 15~20 mm) to achieve satisfactory mixing effect when compared with active mixers. In order to improve the mixing performance, we propose two designs of herringbone patterns based on Stroock´s device. It is demonstrated that the mixing performance can be effectively increased by about 16% under the same channel dimensions and the same steady pressure drop between the inlet and the outlet. The devices are fabricated using micromachining techniques. Experimental verification is also provided