Microplat project : development status

Abstract

In the first few months of the project the CENIMAT partner concentrate their work in the optimization of the microfabrication in SU-8, to make masters for PDMS microchannels and grooves for insertion of optical fibers. SU-8, a negative photoresist, is one of the most used materials in the fabrication of microfluidics, mainly due to its transparency, mechanical, chemical and thermal stability. However, SU-8 is very sensitive to process parameters and the high aspect ratio features are difficult to obtain duo to large internal SU-8 stress that may lead to SU-8 peeling. In the optimization process we were able to fabricate high aspect ratio narrow structures (~ 10µm) with high vertical side-walls (130µm) necessary to insert the fibers and fabricate focusing lenses. The FSCOSD partner in conjunction with CENIMAT concentrated their efforts in the design of detection chamber, which involves optical lenses microfabricated in SU-8. The distances curvature and dimensions of the optical detection chamber play a crucial role in the detection process, so a careful planning and modeling was necessary. This process is now is the step of mask design for photo lithography. The IPC major concern in this initial part of the project was related with conceiving design that allows evaluating the mixing of the fluids inside the channels. Once the channels are microfabricated the mixing will the evaluated through Fluorescent Microscopy.