SU-8 submicrometric sieves recorded by UV interference lithography

Sieves are promising devices for filtration, separation of particles and drug delivery control because of their uniform pore size distribution and low flow resistance. SU-8 is a negative photoresist type epoxy that is hydrophobic and biocompatible. Thus, it is a good alternative to fabricate micro devices for biological applications. In this paper we show a novel fabrication technique of self-sustained sieves of an SU-8 photoresist, with pore dimensions in the range of hundreds of nanometers, using a combination of UV interference and conventional optical lithographies. The resulting sieves are SU-8 membranes with submicrometric pore sizes and coefficient of variation of 7%, in areas of 1 cm 2 .