Boost the voltage of a magnetoelastic generator via tuning the magnetic induction layer resistance. (May 2023) - Ock, Il Woo
Abstract: Using the giant magnetoelastic effect in the soft systems for ambient energy harvesting, namely, the magnetoelastic generator (MEG), is challenged by its relatively low voltage output. A conventional transformer could be employed to solve the problem by increasing the voltage at the expense of current; however, it holds a bulky and rigid configuration with considerable energy loss. Here, we developed the resistance-controllable magnetic induction (MI) layer with multi-walled carbon nanotubes (MWCNT) as an inner transformer to manipulate the electrical output of an MEG. With high electrical conductivity, flexibility, and mechanical strength, the resistance of the MWCNT-based MI layer can be designed by thickness, width, length, and turns of the coils, contributing to a power-transforming effect. As the resistances increased, the open-circuit voltage increased, while the short-circuit current showed a reversed trend. With a power density of 0.23 mV cm −2, the power-transforming MEG can charge a commercial capacitor at a rate of 0.63 mV s −1 with intrinsic waterproofness. This work introduces a compelling approach to boost the voltage output of the MEG via internally engineering the resistance of the MI layer. Graphical Abstract: ga1 Highlights: The MEG could convert mechanical motions into characteristically high current and relatively low voltage signals. MWCNTs was used to fabricate the MI layer that is resistance-tunable, foldable, and stretchable. The resistance-tunable feature of the MI layers brings power-transforming functionality.