Interfacial rheology is key to control the stability of multiphasic assemblies like foams or emulsions as it governs the local interfacial flows between the plateau borders and the thin films. The stability and the foam behavior under drainage for example depend on both elastic and surface viscous moduli. Interfacial rheology also plays a major role in the rheology of suspensions of deformable particles of living fluids like blood. Indeed, the interactions between Red Blood Cells are governed by the mechanical response to the hydrodynamic flow which results from many-body interactions. The shear membrane viscosity has an essential contribution. In many applications in painting or in bioengineering such as encapsulation, self-healing is a sought property to ensure a sufficient life-time of interfaces, much like macromolecular re-assembly, which has its signature in the viscoelastic moduli and the constitutive law governing interfacial rheology. Unfortunately, intrinsic difficulties to measure these properties is blocking progress. This difficulty comes from the quasi-impossibility to quantify independently each parameter as shear and dilatational strains are often concomitant. A good agreement between the different techniques available is only found for scarce cases of surfactants. In the case of microcapsules and their thin biopolymer membranes, the dilatational viscosity and elasticity are nearly always ignored. Gathering a multidisciplinary consortium of three laboratories in physical-chemistry / soft matter (LPS), rheology / fluid mechanics (LRP) and High Performance Computing / mechanics (M2P2), 2DVISC will develop a versatile toolbox to measure the viscoelastic moduli characterizing the interfacial rheology of bubbles, droplets and microcapsules. It means the surface tension, the Marangoni modulus and both shear and dilatational surface viscosities in the case of bubbles and droplets and the shear and dilatational surface elastic moduli and both surface viscosities in the case of microcapsules. The principle is not to control purely shear or dilatational strains (or deformations) but to apply different simple linear flows, each one being characterized by two known components of shear and elongation rates to deform bubbles, droplets and microcapsules using (milli-)microfluidic tools. The overall deformation, orientation and the associated characteristic times depend on the viscoelastic moduli. A careful comparison of the dynamics of deformation and orientation with theoretical expressions determined in the limit of quasi-spherical shapes and advanced numerical models in the linear and nonlinear regimes allow to extract the interfacial surface moduli by inverse analysis. Several flow configurations will be investigated to demonstrate the self-consistency of the method. These parameters will be compared to standard independent measurements to validate the method. Finally, in the case of droplets and microcapsules, the method will be integrated in the microfluidic Four-Roll Mill to provide a unique toolbox. Full interfacial characterization will become possible using a single device.