Stress induced domain wall motion in Zig-zag shaped microwires for energy harvesting in Internet of Things devices
Date of Issue2018
School of Physical and Mathematical Sciences
The recent rise in industrial automation has paved the way for the exponential growth of (Internet of Things) IoT devices. As more of these ‘smart devices’ are integrated into our daily lives, there is a dire need to power these devices with a sustainable energy source . Batteries serve only as a short-term solution, as they would have to be constantly replaced, disrupting the service of the IoT devices. A more reliable way of extracting power from a sustainable energy source is through energy harvesting via inverse magnetostriction. This method makes use of acoustical vibrations such as environmental noise to impose stress on the ferromagnetic material. This stress consequently causes domain wall (DW) motion resulting in changes in the magnetic flux which can be harnessed to produce sustainable electrical energy as per Faraday’s Law. This thesis investigated the effects of the thickness of the ferromagnetic material and the zig-zag shape of the microwire on the stress induced DW motion. The thickness and dimensions of the zig-zag shape of the microwire were varied to form different microwires. They were also exposed to different magnitudes of stress. The different microwires were then assessed on whether they exhibit stress induced DW motion. The results showed that the effects of the thickness of the ferromagnetic material supersedes that of the zig-zag shape when it comes to stress induced DW motion in the ferromagnetic microwires. These results serve as a foundation for future research, where wires can be packed densely together for integration into IoT devices.
Final Year Project (FYP)