The present disclosure provides a method of evaluating a mechanical property of a material using a device for evaluating the mechanical property of the material. The device comprises a sensing layer having a thickness, a sensing surface and an opposite surface. The sensing layer is deformable such that, when the sensing surface is in direct or indirect contact with the material and a suitable load is applied across both the sensing layer and at least a portion of the material, the sensing layer deforms and the sensing surface moves relative to the opposite surface. The device also comprises a source of electromagnetic radiation in optical communication with the sensing layer. The source is arranged for generating electromagnetic radiation having a coherence length that is of the same order of magnitude as the thickness of the sensing layer or longer than the thickness of the sensing layer. Further, the device comprises a detector for detecting the electromagnetic radiation and being in optical communication with the sensing layer and arranged for receiving the electromagnetic radiation after the electromagnetic radiation is reflected at the interface at the sensing surface of the sensing layer. The method comprises positioning the sensing layer relative to the material such that the sensing surface is in direct or indirect contact with the material. Further, the method comprises applying the suitable load across both the sensing layer and at least a portion of the material whereby the sensing layer deforms and the interface at the sensing surface moves relative to a condition in which no load is applied. The method also comprises directing the electromagnetic radiation to the interface at the sensing surface such that at least a portion of the electromagnetic radiation is reflected at the interface at whereby a first signal is generated and directing electromagnetic radiation along a second optical pathlength to generate a second signal. Further, the method comprise
