This paper describes a possible active mixing method for a 30 mu l microbioreactor that was designed, simulated and tested. Pressure based recycle flow was investigated in a cylindrical microreactor for mixing efficiency. Based on the computational fluid dynamics (CFD) simulation results and the requirements of the application, the recycle flow mixing method proved to be suitable as a method to induce sufficient mixing in the microbioreactor. This was verified experimentally using image analysis of dye distribution behavior. (C) 2008 Elsevier Ltd. All rights reserved.