A stress sensing system for sensing stress in a ferromagnetic material, such as a rotatable shaft, in which the permeability of regions change because of stresses applied to the material, the stress sensing system characterized by including a sensor positioned proximate to said ferromagnetic material with a gap defined between said sensor and said ferromagnetic material, said sensor comprising: a non-magnetic substrate (800, 1100) extending in a first, second, and third direction, said substrate (800, 1100) comprising: a first layer (802, 1104) comprising a first bottom surface (806, 1110) and a first top surface opposite said first bottom surface (806, 1110), wherein said first bottom surface (806, 1110) extends along the first direction and the second direction; and a second layer (804, 1106) comprising a second bottom surface (808, 1112) and a second top surface opposite said second bottom surface (808, 1112), said second bottom surface (808, 1112) coupled to said first top surface of said first layer (802, 1104), wherein said second bottom surface (808, 1112) extends along the first direction and the second direction; a first coil (18, 1118) coupled to said second bottom surface (808, 1112) and configured to induce a magnetic flux in the ferromagnetic material, wherein said first coil (18, 1118) is configured to be driven by an alternating current signal; and at least one second coil (28, 1116) coupled to said first bottom surface (806, 1110) and positioned to overlap at least a portion of said first coil (18, 1118) in at least one of the first and second directions, said second coil (28, 1116) configured to detect changes in the magnetic flux induced in the ferromagnetic material. a non-magnetic substrate (800, 1100) extending in a first, second, and third direction, said substrate (800, 1100) comprising: a first layer (802, 1104) comprising a first bottom surface (806, 1110) and a first top surface opposite said first bottom surface (806, 1110), wherein said first bottom surface (806, 1110) extends along the first direction and the second direction; and a second layer (804, 1106) comprising a second bottom surface (808, 1112) and a second top surface opposite said second bottom surface (808, 1112), said second bottom surface (808, 1112) coupled to said first top surface of said first layer (802, 1104), wherein said second bottom surface (808, 1112) extends along the first direction and the second direction; a first layer (802, 1104) comprising a first bottom surface (806, 1110) and a first top surface opposite said first bottom surface (806, 1110), wherein said first bottom surface (806, 1110) extends along the first direction and the second direction; and a second layer (804, 1106) comprising a second bottom surface (808, 1112) and a second top surface opposite said second bottom surface (808, 1112), said second bottom surface (808, 1112) coupled to said first top surface of said first layer (802, 1104), wherein said second bottom surface (808, 1112) extends along the first direction and the second direction; a first coil (18, 1118) coupled to said second bottom surface (808, 1112) and configured to induce a magnetic flux in the ferromagnetic material, wherein said first coil (18, 1118) is configured to be driven by an alternating current signal; and at least one second coil (28, 1116) coupled to said first bottom surface (806, 1110) and positioned to overlap at least a portion of said first coil (18, 1118) in at least one of the first and second directions, said second coil (28, 1116) configured to detect changes in the magnetic flux induced in the ferromagnetic material.