Nonlinear dynamic response of soft thick-walled electro-active tubes

Bortot, Eliana

doi:10.1088/1361-665x/aadbce

Cited by 22 publications

(6 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The effect described in this work could have been predicted (but it was not) as the inverse effect of previously described rubber deformation under an electric field [47], within the framework of linear irreversible thermodynamics. In the present case, the electric field is the result of mechanical action while, in the dielectric membranes used in robotics, the electric field is the agent producing mechanical effects.…”

Section: Discussionmentioning

confidence: 54%

Rubber Surface Change and Static Charging under Periodic Stress

Santos

Campo

Silva

et al. 2018

Colloids and Interfaces

View full text Add to dashboard Cite

Rubber materials play an important role in robotics, due to their sensing and actuating abilities, that are exploited in soft smart materials endowed with shape-adaptive and electroadhesive properties. The application of an electric field produces non-linear deformation that has been extensively modelled, but is not understood at the molecular level. The symmetric effect (the production of an electric field due to rubber deformation) was recently discovered and explained as follows: rubber surface chemical composition and adsorptive properties change during rubber deformation, allowing the surface to exchange charge with the atmosphere. The present work describes the complex surface morphology and microchemistry of tubing made from vulcanized natural rubber, showing that it is rough and made from two domain types: stiffer elevations containing Br or Al (depending on the sample used) and O, that rise above an elastic base that is exempt of elements other than C and H. The surface area fraction occupied by the elastic base is higher in the strained rubber than when it is relaxed. Electrostatic potential on rubber surfaces was measured as a function of the stretching frequency, using Kelvin electrodes and showing frequency-dependent potential variation. This is explained considering charge exchange between the atmosphere and rubber surface, mediated by water vapor adsorbed in the stretched rubber and trapped when it relaxes.Colloids Interfaces 2018, 2, 55 2 of 11 of rubber performance in many important situations, but this does not benefit from knowledge on the molecular mechanisms of the observed phenomena.Recent work from this group described a new finding on the electrostatic behavior of elastomers: in short, rubber tube stretching, followed by relaxation, provokes the appearance of transient excess charge that is more pronounced under higher relative humidity [14]. This effect is not related to any existing electrostatic charging phenomenon (piezoelectricity, flexoelectricity, triboelectricity, and contact charging) and a new mechanism was then proposed to explain charge pick-up and dissipation by stretched elastomers, as the result of water adsorption and the partition of water ions (H + and OH − ) in the rubber-air interface, due to periodic rubber surface modification.Other unexpected findings on electrostatic phenomena in dielectrics have been described recently, leading to a revision of widespread ideas on electrostatic charging and its mechanisms [15]. Important aspects of electrostatic phenomena are not well understood [16][17][18], but tribo-and piezoelectricity are important sources of the electrostatic potentials detected in anthropic environments, often reaching many-thousand volts. They are currently used in nanotribogenerators, with great success. This is creating new opportunities for energy scavenging [19][20][21], and it is probably relevant to the prevention of harmful electrostatic discharge.Knowledge of the electrostatic behavior of elastomers is more limited than in the case of semicrystallin...

show abstract

Section: Discussionmentioning

confidence: 54%

Rubber Surface Change and Static Charging under Periodic Stress

Santos

Campo

Silva

et al. 2018

Colloids and Interfaces

View full text Add to dashboard Cite

show abstract

“…However, an electric voltage beyond the critical value may destroy the spherical shell. Furthermore, Bortot [99] analyzed the nonlinear vibrations of a thick-walled DE cylindrical tube under electric loads. The simulation results revealed that for a constant electric field, the resonance frequency and the oscillation amplitude can be significantly influenced by the tube thickness.…”

Section: Hollow Cylinders and Spheresmentioning

confidence: 99%

Vibrations and waves in soft dielectric elastomer structures

Zhao

Chen²,

Hu³

et al. 2023

International Journal of Mechanical Sciences

View full text Add to dashboard Cite

“…For describing the effect of anisotropy on the electromechanical actuation behaviour of DEs, we present the material model of anisotropic incompressible dielectric elastomers following the same approach used for isotropic dielectrics [43]. In order to model the elastic behaviour of isotropic dielectric elastomers, different hyperelastic material models such as neo-Hookean [10,20,44,45], Mooney-Rivlin [40,46], Ogden [40,44,46], Gent [47,48], Yeoh [9,49], and Arruda-Boyce [50] have been used so far in the literature. In the present investigation, we assume that the dielectric elastomer membrane is made of generalized neo-Hookean material, which is transversely isotropic about one of the lateral direction, i.e., X 1 .…”

Section: Problem Statement and Materials Modelmentioning

confidence: 99%

Effect of anisotropy on the dynamic electromechanical instability of a dielectric elastomer actuator

Sharma

Joglekar

2018

Smart Mater. Struct.

View full text Add to dashboard Cite

Electrically driven dielectric elastomer actuators (DEAs) are susceptible to an electromechanical instability because of a positive feedback between the applied electric field and the concomitant reduction in thickness of the membrane. This paper investigates the effect of material anisotropy on the dynamic electromechanical instability of a dielectric elastomer actuator when subjected to DC and AC voltage signals. We use a computationally efficient energy based Hamiltonian approach, which relies on the energy balance at the position of maximum overshoot in an oscillation cycle, for extracting the DC dynamic instability parameters of a biaxially prestretched anisotropic DEA. Analytical solutions are obtained for static and DC dynamic instability parameters. The AC dynamic instability fields are extracted by numerically integrating the differential equations of motion devised using the Euler–Lagrange equation. The trends of variation of the thickness stretch and electric field on the onset of static and dynamic pull-in instability with the material anisotropy parameter are presented. The results demonstrate a significant enhancement in the deformation and electric field on the onset of electromechanical instability with increase in the anisotropy parameter. The results of the present investigation can find potential application in the development and design of the dielectric elastomer actuator subjected to transient loading.

show abstract

Nonlinear dynamic response of soft thick-walled electro-active tubes

Cited by 22 publications

References 42 publications

Rubber Surface Change and Static Charging under Periodic Stress

Rubber Surface Change and Static Charging under Periodic Stress

Vibrations and waves in soft dielectric elastomer structures

Effect of anisotropy on the dynamic electromechanical instability of a dielectric elastomer actuator

Contact Info

Product

Resources

About