A facile alignment of PDMS layers for the fabrication of 3D microfluidic devices using synergistic zipper structure

This paper describes a simple method for the assembly of three-dimensional (3D) PDMS microfluidic devices using zipper-based microchannel alignment scheme. Mimicking the interlocking teeth of zippers, two PDMS layers are casted with interdigitated teeth so that the alignment of microchannels can be easily and rapidly realized under a regular stereoscope or inverted microscope, and no need for any alignment systems or skillful operators. In addition, this method would also tolerate a small-degree of mismatch between PDMS layers due to PDMS shrinkage when replicating structures, and thus can be used for making 3D microfluidic devices over large surface areas.