Total energy analysis: Impetus-injected bistable vibration energy harvester

Bistable energy harvesters (BEHs) have been extensively explored from the perspective of potential energy. However, few studies have investigated other energy dimensions or proposed optimization routes beyond potential barrier modification. This study presents BEH's total energy analysis framework, incorporating both potential and kinetic energy (Ep and Ek, respectively). Theoretically, these two energy dimensions orthogonally compose the three-dimensional phase space for the total energy (Et). This framework provides additional viewing angles when Ep = const to interpret the BEH's power capacity and suggests an alternative optimization route of improving Ek, which demonstrates a better effect than improving Ep due to the presence of attractors. Based on the total energy analysis framework, impetus injected BEH (IIBEH) is proposed to improve Ek and boost output power by reducing the slope of the restoring force outside the potential barrier. This overcomes the limitation that improving Ek must trigger a velocity disturbance, which is often uncontrollable or impractical in field energy harvesting applications. Experimentally, with only an 8.82% difference in restoring force slope, the IIBEH increases root mean square voltage by 47.75% and average power by 118.43% compared to the conventional BEH.