Various Gedanken experiments have been proposed in the past to test the expression for the electromagnetic energy-momentum tensor in a material medium and hence the ratio of the momentum to the energy carried by the electromagnetic wave in a dielectric medium. We suggest a real experiment, based on the use of atomic force microscopy microcantilevers. We discuss thr phenomenological theoretical framework and the feasibility of our proposal, We report preliminary experimental results obtained in air and water to test the performance of our setup.