Investigation of biogenic materials and ferroelectrets for energy harvesting on vibrating aircraft structures

Abstract

In this publication the application of novel piezoelectric materials for energy harvesting on vibrating aircraft structures is investigated. These materials have significant advantages over conventional piezoelectric transducer materials like piezoceramics. In particular, biogenic materials in the form of wood-based materials and ferroelectrets in the form of irradiation cross-linked polypropylene are the subject of the investigation. The material characterization in terms of mechanical and electromechanical properties is shown for both material types. For the wood materials a compression test is used as the material has load-bearing properties. The ferroelectrets provide high compliances and are therefore investigated in a tensile test for material characterisation as well as in a four-point flexural test regarding its behaviour when glued to a dynamically bending surface. Additionally an FE-model of the material model for ferroelectrets is presented, which is validated by experimental results. An estimation of the power output is given for different concepts with both kinds of materials.

Design and optimization of lightweight bending strain energy harvesters using irradiation cross-linked polypropylene ferroelectret

“…The strain energy of a bending mechanical structure is only available in the in-plane-direction. In a former work, the IXPP sheet was loaded in the δ 31 -mode as the easiest possible way of the patch to be attached to the structure [3]. This is analogous to the use of a piezoceramic patch, but it is not the mode, that leverages the energy conversion properties of IXPP optimally.…”

“…0.7 MPa [35] dynamic behavior. For both approaches, small deflections and linear material properties are assumed similar to [3]. For the IXPP ferroelectret, the properties shown in table 1 are assumed using a transversely isotropic material model.…”

“…The wing is of special interest for energy harvesting, since a large part of it is fairly remote of the central energy supply and therefore a replacement of cables potentially saves a considerable amount of weight. Prior work [3,4] has shown that strain magnitudes, that could be used by the EH, are especially high in a low frequency range, apart from the eigenfrequency of the EH itself. Because of this, it can be useful to design an EH without an additional resonator mass for very low frequency applications to minimize its total mass.…”

Ferroelectrets: Recent developments

“…[74,75] Luo et al prepared an 80-layer ferroelectret energy harvesting insole, which could harvest about 100 μJ energy per footstep of a person 80 kg in weight [76,77]. Later, by using newly developed, thermally stable ferroelectrets with large longitudinal and/or transverse piezoelectricity, power outputs of up to more than 100 μW were achieved [78][79][80][81][82][83][84][85][86][87][88][89]. Zhang et al prepared radiation-crosslinked PP (IXPP) ferroelectrets with improved piezoelectric sensitivity and better thermal stability as compared with normal cellular PP ferroelectrets [78].…”

“…prepared an 80‐layer ferroelectret energy harvesting insole, which could harvest about 100 μJ energy per footstep of a person 80 kg in weight [76, 77]. Later, by using newly developed, thermally stable ferroelectrets with large longitudinal and/or transverse piezoelectricity, power outputs of up to more than 100 μW were achieved [78–89]. Zhang et al.…”