Owing to their promising applications, especially in spintronics, multiferroics have been at the fprefront of condensed matter research for a number of years. In these materials, ferroelectric and antiferromagnetic orders are strongly coupled, the so-called magneto-electric (ME) coupling allowing the reversal of the ferroelectric (FE) polarization by a magnetic field or the control of the magnetic order parameter by an electric field. For creating functional devices, thin films operating at room temperature are a must. BiFeO3 (BFO) is perhaps the most famous example and is the object of this proposal. Following our recent work tuning the complex magnetic structure in BFO by misfit strains, in particular by destabilizing the bulk-like cycloid modulation, we would like to study the modification of magnetic structure through high resolution neutron scattering on strained BFO films.