Flexible thin film magnetoimpedance sensors

• [FeNi/Ti]3/Cu/[FeNi/Ti]3 films were prepared by sputtering at different deposition rates.
• Polymer substrates insure sufficiently accurate reproducibility of the film structure.
• High deposition rate of 28 nm/min insures the highest values of the magnetoimpedance sensitivity.
• Deposition onto polymer results in the satisfactory magnetoimpedance sensitivity of 45%/Oe.

Magnetically soft thin film deposited onto polymer substrates is an attractive option for flexible electronics including magnetoimpedance (MI) applications. MI FeNi/Ti based thin film sensitive elements were designed and prepared using the sputtering technique by deposition onto rigid and flexible substrates at different deposition rates. Their structure, magnetic properties and MI were comparatively analyzed. The main structural features were sufficiently accurately reproduced in the case of deposition onto cyclo olefine polymer substrates compared to glass substrates for the same conditions. Although for the best condition (28 nm/min rate) of the deposition onto polymer a significant reduction of the MI field sensitivity was found satisfactory for sensor applications sensitivity: 45%/Oe was obtained for a frequency of 60 MHz.