Micro rheology is a field in which the study of viscoelasticity of materials serves to consider how their dynamic behavior changes with length scale. Applied to complex fluids, this field is of extreme industrial importance: from paints to foods, from oil recovery to processing of plastics, understanding the flow of complex fluids is essential to a wide range of technologies. The microrheology of complex systems still faces significant challenges: 1) in situ measurements within confined systems; 2) on line measurements in dynamic microsystems, and 3) viscosity mapping at the nanoscale. Microrheology is closely connected to the field of microfluidics, which considers phenomena such as those involved in ink jet printing, 3D printing, microelectrophoresis on a chip, microvalves and the kinetics of protein crystallization. The overlap is thus quite strong and the fluid mechanics of materials in confined geometries is a common area to the two research fields. The dynamics and the microrheological behavior of confined fluids often change dramatically when, for instance, they are confined near a surface. The interfacial characteristics of gas, liquid and solid interfaces all require individually optimized methods for the measurement of the surface microrheology. Even more, traditional mechanical viscometers are not able to measure viscosity of microsystems and, more important, they cannot measure microviscosities in real-time conditions or perform time- and spatially-resolved mapping of the microviscosities in confined systems. MICROVISCOTOR proposes an innovative strategy to develop a cost-effective microfluidics device capable to measure and map on-line and in real-time spatially- and time-resolved microviscosities of fluids by using molecular rotors. The strategy presented here is applied to microfluidic processes with the aim to develop low-cost “lab on a chip” devices or sensors.