Fabrication and characterization of magnetostrictive cantilever beams for magnetic actuation

The need for magnetostrictive materials is growing for applications in microelectromechanical systems (MEMS) and microelectronic devices due to their ability to enable remote control via magnetic fields. This work studies an alloy of Iron and Gallium, Galfenol (thin films), and its magnetostrictive properties on a nano scale, finding approaches to increase the magnetostriction coefficient of thin-film Galfenol in the magnetostrictive cantilever beam fabrication process. One goal of this work is to build a non-direct contact micro actuator for use as a drug delivery device to the human eye, using Galfenol as the magnetostrictive material. Silicon Nitride cantilever beams were fabricated and Galfenol thin films, deposited under different conditions with Radio Frequency (RF) sputtering, were studied on different platforms. For the different films samples, Vibrating Sample Magnetometry (VSM) was carried out to check for certain magnetic properties. X-Ray Diffraction (XRD) was used to study the lattice structure of the films, and Energy Dispersive Spectrometry (EDS) was used to determine the percentage element composition of the films to investigate how it affects the magnetostriction. Galfenol thin films were deposited using RF sputtering; for a film sample sputtered with a forward power of 150W, gas flow rate of 30sccm for 120 minutes, outcome of VSM showed a coercivity of 25.869 G, retentivity of 16.574 × 10 ^-3 emu and magnetization of 38.30 × 10 ^-3 emu. XRD indicated that the films were composed of α-Fe and EDS showed that Iron dominated the percentage element composition of the film sample, approximating 68%. esults from the study yielded magnetostriction coefficient as high as 83ppm. Magnetostriction coefficient was dependent on the thickness and percentage element composition of the films, which also depend on the deposition conditions, especially the forward power used in sputtering.