### Abstract

Nonlinear energy harvesters are frequently considered in preference to linear devices because they can potentially overcome the narrow frequency bandwidth limitations inherent to linear variants however, the possibility of variable harvesting efficiency is raised for the nonlinear case. This paper proposes a rotational energy harvester which may be fitted into an automobile tyre, with the advantage that it may broaden the rotating frequency bandwidth and simultaneously stabilise high-energy orbit oscillations. By consideration of the centrifugal effects due to rotation, the overall restoring force will potentially be increased for a cantilever implemented within the harvester, and this manifests as an increase in its equivalent elastic stiffness. In addition, this study reveals that the initial potential well barriers become as shallow as those for a bistable system. When the rotational frequency increases beyond an identifiable boundary frequency, the system transforms into one with a potential barrier of a typical monostable system. On this basis, the inter-well motion of the bistable system can provide sufficient kinetic energy so that the cantilever maintains its high-energy orbit oscillation for monostable hardening behaviour. Furthermore, in a vehicle drive experiment, it has been shown that the effective rotating frequency bandwidth can be widened from 15 km/h-25 km/h to 10 km/h-40 km/h. In addition, it is confirmed that the centrifugal effects can improve the harvester performance, producing a mean power of 61 μW at a driving speed of 40 km/h, and this is achieved by stabilising the high-energy orbit oscillations of the rotational harvester.

Original language | English |
---|---|

Article number | 143901 |

Number of pages | 5 |

Journal | Applied Physics Letters |

Volume | 112 |

Issue number | 14 |

DOIs | |

Publication status | Published - 2 Apr 2018 |

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### Keywords

- elasticity
- rotational dynamics
- kinematics
- mechanical systems
- mechanical testing
- optical bistability

### Cite this

*Applied Physics Letters*,

*112*(14), [143901]. https://doi.org/10.1063/1.5019907

}

*Applied Physics Letters*, vol. 112, no. 14, 143901. https://doi.org/10.1063/1.5019907

**Stabilising high energy orbit oscillations by the utilisation of centrifugal effects for rotating-tyre-induced energy harvesting.** / Zhang, Yunshun; Zheng, Rencheng; Nakano, Kimihiko; Cartmell, Matthew P.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Stabilising high energy orbit oscillations by the utilisation of centrifugal effects for rotating-tyre-induced energy harvesting

AU - Zhang, Yunshun

AU - Zheng, Rencheng

AU - Nakano, Kimihiko

AU - Cartmell, Matthew P.

N1 - This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in Zhang, Y, Zheng, R, Nakano, K & Cartmell, MP 2018, 'Stabilising high energy orbit oscillations by the utilisation of centrifugal effects for rotating-tyre-induced energy harvesting' Applied Physics Letters, vol 112, no. 14, 143901 and may be found at https://doi.org/10.1063/1.5019907.

PY - 2018/4/2

Y1 - 2018/4/2

N2 - Nonlinear energy harvesters are frequently considered in preference to linear devices because they can potentially overcome the narrow frequency bandwidth limitations inherent to linear variants however, the possibility of variable harvesting efficiency is raised for the nonlinear case. This paper proposes a rotational energy harvester which may be fitted into an automobile tyre, with the advantage that it may broaden the rotating frequency bandwidth and simultaneously stabilise high-energy orbit oscillations. By consideration of the centrifugal effects due to rotation, the overall restoring force will potentially be increased for a cantilever implemented within the harvester, and this manifests as an increase in its equivalent elastic stiffness. In addition, this study reveals that the initial potential well barriers become as shallow as those for a bistable system. When the rotational frequency increases beyond an identifiable boundary frequency, the system transforms into one with a potential barrier of a typical monostable system. On this basis, the inter-well motion of the bistable system can provide sufficient kinetic energy so that the cantilever maintains its high-energy orbit oscillation for monostable hardening behaviour. Furthermore, in a vehicle drive experiment, it has been shown that the effective rotating frequency bandwidth can be widened from 15 km/h-25 km/h to 10 km/h-40 km/h. In addition, it is confirmed that the centrifugal effects can improve the harvester performance, producing a mean power of 61 μW at a driving speed of 40 km/h, and this is achieved by stabilising the high-energy orbit oscillations of the rotational harvester.

AB - Nonlinear energy harvesters are frequently considered in preference to linear devices because they can potentially overcome the narrow frequency bandwidth limitations inherent to linear variants however, the possibility of variable harvesting efficiency is raised for the nonlinear case. This paper proposes a rotational energy harvester which may be fitted into an automobile tyre, with the advantage that it may broaden the rotating frequency bandwidth and simultaneously stabilise high-energy orbit oscillations. By consideration of the centrifugal effects due to rotation, the overall restoring force will potentially be increased for a cantilever implemented within the harvester, and this manifests as an increase in its equivalent elastic stiffness. In addition, this study reveals that the initial potential well barriers become as shallow as those for a bistable system. When the rotational frequency increases beyond an identifiable boundary frequency, the system transforms into one with a potential barrier of a typical monostable system. On this basis, the inter-well motion of the bistable system can provide sufficient kinetic energy so that the cantilever maintains its high-energy orbit oscillation for monostable hardening behaviour. Furthermore, in a vehicle drive experiment, it has been shown that the effective rotating frequency bandwidth can be widened from 15 km/h-25 km/h to 10 km/h-40 km/h. In addition, it is confirmed that the centrifugal effects can improve the harvester performance, producing a mean power of 61 μW at a driving speed of 40 km/h, and this is achieved by stabilising the high-energy orbit oscillations of the rotational harvester.

KW - elasticity

KW - rotational dynamics

KW - kinematics

KW - mechanical systems

KW - mechanical testing

KW - optical bistability

UR - http://www.scopus.com/inward/record.url?scp=85044933703&partnerID=8YFLogxK

UR - https://aip.scitation.org/journal/apl

U2 - 10.1063/1.5019907

DO - 10.1063/1.5019907

M3 - Article

VL - 112

JO - Applied Physics Letters

JF - Applied Physics Letters

SN - 0003-6951

IS - 14

M1 - 143901

ER -