Zurich University of Applied Sciences, School of Life Sciences and Facility Management 2 articles published in JoVE Bioengineering Power Input Measurements in Stirred Bioreactors at Laboratory Scale Stephan C. Kaiser1, Sören Werner2, Valentin Jossen2, Katharina Blaschczok2, Dieter Eibl2 1Finesse, Thermo Fisher Scientific, 2Institute of Chemistry and Biotechnology, Zurich University of Applied Sciences, School of Life Sciences and Facility Management The power input in stirred bioreactors can be measured through the torque that acts on the impeller shaft during rotation. This manuscript describes how an air bearing can be used to effectively reduce friction losses observed in mechanical seals and improve the accuracy of power input measurements in small-scale vessels. Engineering A Cost-effective and Reliable Method to Predict Mechanical Stress in Single-use and Standard Pumps Ina Dittler1, Wolfgang Dornfeld2, Reto Schöb2, Jared Cocke3, Jürgen Rojahn3, Matthias Kraume4, Dieter Eibl1 1Institute of Biotechnology, School of Life Sciences and Facility Management, Zurich University of Applied Sciences, 2Levitronix Ltd., 3SOPAT Ltd., 4Institute of Chemical and Process Engineering, Technische Universität Berlin Shear stress investigations on an oil-water emulsion system result in drop breakup over the experimental time. To count drop sizes in pumping processes, the suitability of inline endoscopy was successfully demonstrated in this protocol.