Non-resonant energy harvesting via an adaptive bistable potential

Abstract

Abstract. Narrow bandwidth and easy detuning, inefficiency in broadband and non-stationary excitations, and difficulties in matching linear harvester's resonance frequency to low-frequency excitations at small scales, have convinced the researchers to investigate the nonlinear, in particular the bistable energy harvesters in the recent years. However, the bistable harvesters suffer from co-existing low and high energy orbits, and sensitivity to initial conditions, and have been recently proven inefficient when subjected to many real-world random and non-stationary excitations. Here, we propose a novel buy-low-sell-high strategy that can significantly improve the harvester's efficiency at low-frequencies in a much more robust fashion. This strategy could be realized by a passive adaptive bistable system. Simulation results confirm high efficiency of the adaptive bistable system following a buy-low-sell-high logic when subjected to harmonic and random non-stationary walking excitations compared to its conventional bistable and linear counterparts.

Fundamental Limits to Nonlinear Energy Harvesting

“…One of the key challenges in designing nonlinear harvesters is the immense range of possible nonlinearities. Among different types of nonlinearity, bistability has received more attention in the past few years [6][7][8][9][10]. However, the question of what are the fundamental limitations of nonlinear energy harvesting is still open.…”

Optimization of vibratory energy harvesters with stochastic parametric uncertainty: a new perspective

“…Finding exact or approximate optimal deterministic parameters for electromagnetic 2 and piezoelectric 3-7 energy harvesters has been comprehensively studied in the literature for the linear harvesters. For the nonlinear energy harvesters, researchers have mainly studied the effects of mechanical potential shape [8][9][10][11][12] or the harvesting circuitry. [13][14][15] All these studies have assumed deterministic system parameters to optimize the harvested power; however, manufacturing tolerances, wear and tear, material degradation, humidity, temperature, and other environmental conditions result in parametric uncertainty in the system and hence in a less-effective detuned harvester.…”

Optimal control strategies for efficient energy harvesting from ambient vibration

“…[2] provides a comprehensive review and discussion for various types of nonlinearities studied in the literature. However, the system response and efficiency remains to be sensitive to the initial conditions (co-existing low-energy and high-energy orbits) [12], [15]- [17], potential shape and acceleration intensity [18]- [23], and nature of the excitation [24]. Similar studies have been done in the harvesting circuitry design to increase the harvesting power available in the mechanical domain.…”