While our understanding of which factors influence protein crystallization is increasring, identifying suitable crystallization conditions for a novel protein is still much more art than a science. To determine optimal conditions for crystallization high throughput methods are used that utilize sparse matrix methods. Oftentimes, these experiments are carried out in ‘well' plates dedicated for crystallization studies and these are filled using large and costly fluid handling equipment. Integrated microfluidic systems that are able to perform sparse matrix screens for suitable crystallization conditions can be created. These systems can be filled and operated without the need for large fluid handling systems, and the amount of precious protein needed per well or per screened condition is much smaller. Here we will report on the design, fabrication, and testing of evaporation-based microfluidic crystallization screening platforms with individual well volumes on the order of a few nanoliter. Moreover, we will present a microfluidic device designed for the on-chip screening of crystallization conditions for membrane-type proteins in a lipidic phase.