Non-contact gap sensor system completely made of conductive polymer composite

Both of the coil and the object of the traditional eddy current non-contact gap sensor system are made of metal. However, the rigidness of metal makes it difficult to develop a stretchable coil with low cost, and the system cannot work if the object is non-metallic. To overcome the limitations, an eddy current non-contact gap sensor system, in which both the coil and the object are made of stretchable conductive polymer composite, is designed. The current in the composite coil causes an induced current in the composite object covered on the non-metallic surface, leading to the occurrence of the eddy current effect. The experimental data show that the impedance of the composite coil changes regularly with the lift-off. The results verify the feasibility of using the system completely made of the composite to measure the non-contact gap between the non-metallic surfaces.