Ultra-thin Pt\Co\Pt trilayers exhibit perpendicular, out-of-plane magnetization. The ferromagnetic cobalt layer induces magnetization in the platinum layers, in what is known as magnetic proximity effect. We use scanning Superconducting QUantum Interference Device (SQUID) to study the extent of the proximity effect, i.e. the length that the magnetization is induced in the platinum layer. In addition, we show that we can manipulate the magnetic domains by locally applied stress.  Local control of magnetic domains without applying magnetic field may assist in developing memory and additional novel devices, based on magnetoresistance effects (specifically giant magnetoresistance effect).