Cost-effective thermal isolation techniques for use on microfabricated DNA amplification and analysis devices

Abstract

In this paper, we describe the design, construction and operation of two low cost thermal isolation techniques on a microfabricated DNA amplification and analysis device. The thermal conduit technique is based on a selective conduction mechanism, while the silicon back dicing technique is based on a selective insulation mechanism. The performances of the two techniques are compared both numerically and experimentally to that of the widely adopted but costly silicon back etching technique. Temperature gradients as high as 108°C cm-1, 92°C cm-1 and 158°C cm -1 can be achieved with the three techniques, respectively. Geometric optimization of the two low cost techniques is carried out to further improve their thermal performances. Combining those two techniques can provide comparable thermal isolation results as the back etching technique with significant cost reduction.