Vibration energy-harvesting using inerter-based two-degrees-of-freedom system

Rotary electromagnetic generators that have high power density, large output, and rotational inertia are increasingly used in vibration energy-harvesting systems. When applied to single-degree-of-freedom (SDOF) systems, it is found the inertance reduces system frequency bandwidth. Furthermore, maximum output of SDOF systems limited by mechanical damping allowable stroke. Two-degrees-of-freedom (2DOF) been proposed recent years demonstrated larger wider bandwidth compared with However, a considerable additional physical mass has be added an create 2DOF system, which may increase total weight requires more space. By utilizing generator line-to-rotation mechanism as inerter, inerter-based neglectable proposed, spring inerter connected series between primary base. Parameters including ratio, tuning were optimized for system. Optimal specific stroke limitation was obtained. A benchmark test using energy harvesting backpack done validate analysis results. Both analyses experimental tests show can power-to-stroke ratio its counterpart. The conversion efficiency also improved. Compared conventional not only lightweight but less sensitive parameter changes.