Nondestructive evaluation of nanostructured components using Eddy current microsensor

Abstract

Nanostructured materials (NMs) are used in the manufacture of microsensors and some MEMS devices, include nanoscale wires, carbon nanotubes, biomaterials, etc. Nondestructive evaluation of structural integrity of NMs can be carried out by optical (SEM, EBDS) and electromagnetic methods (eddy current). Due to small dimensions of the objects to be tested, the eddy current sensors used in detection of possible discontinuities requires miniaturization so that the answer in amplitude and phase shall allow their localization. In the case of thin tubes made of 304 hard stainless steel, with outer diameters 332μm and wall thickness 38 μm used in medical devices, intended for special catheters, their small dimensions and possible discontinuities require encircling sensor working at high frequencies of the order of MHz. The paper presents the investigation of small diameter tubes using an Eddy current microsensor and the results obtained at the detection of artificial flaws in order to increase the probability of detection (POD), for a high reliability coefficient.