A continuous flow microfluidic chip with integrated concentration gradient generator for cell culturing

In this work a continuous flow microfluidic siliconglass chip is fabricated for passive generation of a binary logarithmic concentration profile with ten dilutions of an arbitrary fluid in a buffer, including ten integrated cell culture wells. The dilution ratios range from 1:1 down to 1:1023. Two designs with different etch depths and two silicon dioxide surface coatings with different thicknesses are compared regarding their fluidic resistances and performance. Two measurement methods are employed: mass spectrometry and photometry. Additionally, a pilot test for in vitro cell culturing with HeLa cells is performed for up to 24 h. The effect of the substance under investigation on the cells can be monitored by optical microscopy.