A sensor for sensing stress in a ferromagnetic material includes a non-magnetic substrate. The substrate has a first surface and a second surface opposite the first surface. A first coil is attached to or formed on the first surface of the substrate. The first coil is configured to induce a magnetic flux in the ferromagnetic material being driven by an alternating current (AC) signal. At least one second coil is attached to or formed on the first surface of the substrate. The at least one second coil is spaced from the first coil. In addition, the second coil is configured to detect changes in the magnetic flux induced in the ferromagnetic material.