We investigated the impact of polymer substrates on the magnetic properties of soft magnetic thin films. Experiments were carried out to evaluate the performance of AMR (anisotropic magnetoresistive) sensors deposited on polymeric substrates and to give indications for the design of future sensors on flexible substrates. Sputtered permalloy (NiFe 81/19) was used as a soft magnetic thin film layer. As substrate materials, liquid polyimide precursors and DuPont Kapton® HN foil were examined. Surface roughness was determined for each substrate material. The dynamic of soft magnetic behavior of the permalloy thin films was observed in a homogenous alternating magnetic field. Resulting R-Hcurves were evaluated in regard to the magnitude of the magnetoresistive effect (ΔR / R0-ratio), as well as the resulting magnetic anisotropy of the tested samples. B-H-curves were obtained by means of a vibrating sample magnetometer (VSM).

Date Published: 21 May 2015
PDF: 9 pages
Proc. SPIE 9517, Smart Sensors, Actuators, and MEMS VII; and Cyber Physical Systems, 95171R (21 May 2015); doi: 10.1117/12.2178765

Published in SPIE Proceedings Vol. 9517:
Smart Sensors, Actuators, and MEMS VII; and Cyber Physical Systems
José Luis Sánchez-Rojas; Riccardo Brama, Editor(s)