In-chip direct laser writing of a centimeter-scale acoustic micromixer

A centimeter-scale micromixer was fabricated by two-photon polymerization inside a closed microchannel using direct laser writing. The structure consists of a repeating pattern of 20 mu m x 20 mu m x 155 mu m acrylate pillars and extends over 1.2 cm. Using external ultrasonic actuation, the micropillars locally induce streaming with flow speeds of 30 mu m s(-1). The fabrication method allows for large flexibility and more complex designs. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License.