Modeling of a Symmetric Five-Bar Displacement Amplification Compliant Mechanism for Energy Harvesting

Abstract

This paper presents an analytical model to determine a closed form mathematical representation for the output displacement of a displacement amplification compliant mechanism used for energy harvesting. A symmetric five-bar compliant mechanism with right-circular and corner-filleted flexure hinges was mathematically modeled and its displacement was determined using the Castigliano energy theorem. The stresses within the flexure joints, the weakest points in the mechanism body, were calculated. The mathematical model expresses both the displacement amplification and the stresses as functions of the design parameters and the load caused by the harvester. The developed model can be used to optimize the mechanism dimensions for maximum harvested power, while minimizing its structural stresses. The mechanism was also modeled numerically using finite element methods; both the analytical and numerical models were verified experimentally. The mathematical model of the mechanism was integrated with a model representing a piezoelectric energy harvester to calculate the open-circuit voltage. As a proof of concept, experiments were performed using an unimorph piezoelectric cantilever at low-frequency (less than 1 Hz) harmonic excitation inputs. The measured open-circuit voltage was found to be in agreement with that calculated using the proposed model, when integrated with the model representing the piezoelectric beam. The power generated by the piezoelectric harvester, equipped with the proposed displacement amplification mechanism, was more than a hundred times that without amplification.

Design and Experiment of Greenhouse Self-Balancing Mobile Robot Based on PR Joint Sensor

“…The flexible hinge uses the small-angle elastic deformation of the thinnest part of its overall structure to achieve hinged-like motion and transmit force and displacement [32]. It combines the advantages of a flexible motion pair and has the advantages of high sensitivity and fast response.…”

Development of a Large-Range XY-Compliant Micropositioning Stage with Laser-Based Sensing and Active Disturbance Rejection Control

“…In addition, as such mechanisms are usually manufactured monolithically, the manufacturing cost, assembly error, and complexity are reduced considerably [ 4 ]. Due to their indispensable properties of precision and accuracy, compliant mechanisms have been researched for use in various fields, including the medical sector [ 5 , 6 , 7 ], space and aerospace industries [ 8 , 9 ], micro/nano manipulation [ 10 , 11 , 12 , 13 , 14 ], robotics [ 15 , 16 , 17 , 18 ], and energy harvesting [ 19 ].…”

Analysis and Optimization of Dynamic and Static Characteristics of the Compliant-Amplifying Mechanisms

“…Investigations have shown that research on static modeling of the compliant-amplifying mechanism has attracted a great deal of attention, and the methods used [ 18 ] mainly include Castigliano’s second theorem [ 2 , 19 , 20 , 21 , 22 ], the flexibility matrix method [ 23 , 24 , 25 , 26 , 27 , 28 ], the matrix displacement method [ 1 , 29 , 30 ], the elastic beam theory [ 31 , 32 , 33 , 34 , 35 , 36 , 37 ], and kinematic principles [ 35 , 38 , 39 , 40 , 41 , 42 ]. Based on these methods, the effects of the main parameters of the mechanism on its static characteristics have been analyzed, and the relationship between the input and output displacements of the mechanism was established.…”