Dual-Mode Sensing Based on Oriented Magnetostrictive Films by Electrodepositon
Qian Wang, Mingming Li, Ling Weng, Wenmei Huang · IEEE Sensors Journal · 2024
By applying a magnetic field during the electrodeposition process, oriented magnetostrictive Co70Fe30 films were obtained. As the external magnetic field increases, the (200) easy magnetization direction of Co70Fe30 films becomes more obvious, thereby improving the magnetostriction and soft magnetic properties in this direction. Applying magnetic field in the process of films also improves the crystallization quality by orientating the crystal growth. The dynamic hysteresis loops of Co70Fe30 films were measured at different ac driving frequencies f (1–9 kHz) and magnetic field intensity${H}_{m}$(5–25 kA/m), which indicate that the irreversibility of the magnetization process is reduced and the magnetic energy loss reduction reaches up to 20.87% after magnetic field preparation. Based on the dynamic magnetic properties of Co70Fe30 film, this article proposes a new dual-mode flexible sensor for measuring bending strain and magnetic field, which consists of two-layer flexible printed circuit (FPC) coils and one-layer electrodeposited Co-Fe film. The maximum bending strain sensitivity of this sensor is 22 mV/mm in the curvature radius of 10–65 mm, and the maximum magnetic field sensitivity can reach 1.78 mV/(kA/m) in the magnetic field of 1–11 kA/m. The 12 hand gestures, confused by traditional stress/bend sensors, are classified and recognized based on new bi-perceptive sensors with 95.83% accuracy by the naive Bayes classifier.