Authors: Y.T. Zhang, H. Chen, I. Mezic, C.D. Meinhart, L. Petzold and N.C. MacDonald
Affilation: university of california, santa barbara, United States
Pages: 292 - 295
Keywords: Silicon bulk micromachining, SOI, FIB, chaotic mixer, electroosmotic flow
Micromixing has been an active research area in the past decade due to the rapid expanding application of the lab-on-a-chip system in life science. Using the silicon bulk micromachining technology, a ring electroosmotic micromixer, which uses a novel arrangement of electrodes and flow obstacles to induce chaotic mixing, has been designed and fabricated. The design idea uses heavily doped silicon as the fabrication material, and SOI wafer to ensure the electrical isolation of the device from the substrate. The isolation between the electrode and the non-conducting structures is achieved by thermally growing SiO2 to fill the gaps between the two areas. The SOI processing and the later Focused Ion Beam (FIB) modification method produces integrated electrodes to the full depth of the microfluidic system. Other components of the lab-on-a-chip system can be fabricated following the same process flow. A 25-micron wide, 50-micron deep mixer has been fabricated and assembled for later testing.