A Planar Architecture with Dual-Nonlinearity for Bandwidth Extension of a Multi-Modal Energy Harvester

A novel planar architecture with dual-nonlinearity mechanism is proposed for broadening bandwidth of a two-degree-of-freedom (2DOF) MEMS energy harvester. Two micro springs with different inherent nonlinearity are incorporated into the inner and outer oscillation stage of a 2DOF planar spring-mass resonator, helping to generate double hardening nonlinear responses with increased bandwidth, and for the first time, overcoming the deep valley separating neighboring resonances in multi-modal system. This characteristic leads to an ultra-wide operation bandwidth covering two adjacent nonlinear responses. Test results show that at the acceleration of 1g, a continuous energy spectrum with half power bandwidth over 100Hz and high normalized power density of 952 μWcm ^-3 g ^-2 are achieved.