Antagonist Concepts of Polypyrrole Actuators: Bending Hybrid Actuator and Mirrored Trilayer Linear Actuator.
Ontology highlight
ABSTRACT:
SUBMITTER: Kiefer R
PROVIDER: S-EPMC7999340 | biostudies-literature | 2021 Mar
REPOSITORIES: biostudies-literature
Publications
Antagonist Concepts of Polypyrrole Actuators: Bending Hybrid Actuator and Mirrored Trilayer Linear Actuator.
Kiefer Rudolf R Nguyen Ngoc Tuan NT Le Quoc Bao QB Anbarjafari Gholamreza G Tamm Tarmo T
Polymers 20210311 6
Following the natural muscle antagonist actuation principle, different adaptations for "artificial muscles" are introduced in this work. Polypyrrole (PPy) films of different polymerization techniques (potentiostatic and galvanostatic) were analyzed and their established responses were combined in several ways, resulting in beneficial actuation modes. A consecutive "one-pot" electrosynthesis of two layers with the different deposition regimes resulted in an all-PPy bending hybrid actuator. While ...[more]
Similar Datasets
Project description:Conducting polymer actuators have shown wide application prospects in the field of biomedical sensors and micro-/nanorobotics. In order to explore more applications in biomedical sensing and robotics, it is essential to understand the actuator static behavior from an engineering perspective, before incorporating them into a design. In this article, we have established the mathematical model of a trilayer polypyrrole (PPy) cantilever actuator and validated it experimentally. The model helps in enhancing the efficiency and in improving the performance, predictability, and control of the actuator. The thermal expansion analogy, which is similar to volume change of the multilayer PPy actuator due to ion migration, has been considered to develop a mathematical model in COMSOL Multiphysics. To further validate the actuator deformation predicted by the mathematical modeling, a multilayer PPy actuator was fabricated by electrochemical synthesis and the experimentally determined deflection of the actuator was compared to simulation data. Both the theoretical and experimental results depict that the model is effective for predicting the bending behavior of multilayer PPy actuators at different input voltages.
| S-EPMC6648300 | biostudies-literature
Project description:Either as salts or room temperature ionic liquids, fluorinated anion-based electrolytes have been a common choice for ionic electroactive polymer actuators, both linear and bending. In the present work, propylene carbonate solutions of four electrolytes of the three hugely popular anions-triflouromethanesulfonate, bis(trifluoromethane)sulfonimide, and hexafluorophosphate were compared and evaluated in polypyrrole linear actuators. The actuation direction, the characteristics-performance relations influence the behavior of the actuators. Isotonic Electro-chemo-mechanical deformation (ECMD) measurements were performed to study the response of the PPy/DBS samples. The highest strain for pristine PPy/DBS linear actuators was found in range of 21% for LiTFSI, while TBAPF6 had the least cation involvement, suggesting the potential for application in durable and controllable actuators. Interesting cation effects on the actuation of the same anions (CF3SO3-) were also observed.
| S-EPMC6571709 | biostudies-literature
Project description:The paper presents a numerical and experimental investigation of a novel two degrees of freedom (2-DOF) piezoelectric actuator that can generate rotary motion of the sphere-shaped rotor as well as induce planar motion of the flat stage. The actuator has a small size and simple design and can be integrated into a printed circuit board (PCB). The application field of the actuator is small-dimensional and high-precision positioning systems. The piezoelectric actuator comprises three rectangular bimorph plates joined with arcs and arranged by an angle of 120 degrees. A high-stiffness rod is glued on the top surface of each bimorph plate and is used to rotate the rotor or move flat stage employing contact friction force. Three U-shaped structures are used for the actuator clamping. 2-DOF rotational or planar movement is obtained by applying a harmonic or asymmetric electrical signal. The operation principle of the actuator is based on the superposition of the B20 out-of-plane bending mode of the bimorph plates and the B03 radial vibration mode of the ring. Design optimization has been performed to maximize amplitudes of contact point vibration. A prototype of the actuator was made, and a maximum rotation speed of 795.15 RPM was achieved while preload of 546.03 mN was applied. The linear velocity of 36.45 mm/s was obtained at the same preload force. Resolution measurement showed that the actuator can achieve an angular resolution of 17.48 µrad and a linear resolution of 2.75 µm.
| S-EPMC8234698 | biostudies-literature
Project description:Controllable linear actuation of polypyrrole (PPy) is the envisaged goal where only one ion dominates direction (here anions) in reversible redox cycles. PPy with polyethylene oxide (PEO) doped with dodecylbenzenesulfonate forms PPy-PEO/DBS films (PPy-PEO), which are applied in propylene carbonate (PC) solvent with electrolytes such as 1-ethyl-2,3-dimethylimidazolium trifluoromethanesulfonate (EDMICF3SO3), sodium perchlorate (NaClO4) and tetrabutylammonium hexafluorophosphate (TBAPF6) and compared in their linear actuation properties with pristine PPy/DBS samples. PPy-PEO showed for all applied electrolytes that only expansion at oxidation appeared in cyclic voltammetric studies, while pristine PPy/DBS had mixed-ion actuation in all electrolytes. The electrolyte TBAPF6-PC revealed for PPy-PEO best results with 18% strain (PPy/DBS had 8.5% strain), 2 times better strain rates, 1.8 times higher electronic conductivity, 1.4 times higher charge densities and 1.5 times higher diffusion coefficients in comparison to PPy/DBS. Long-term measurements up to 1000 cycles at 0.1 Hz revealed strain over 4% for PPy-PEO linear actuators, showing that combination of PPy/DBS with PEO gives excellent material for artificial muscle-like applications envisaged for smart textiles and soft robotics. FTIR and Raman spectroscopy confirmed PEO content in PPy. Electrochemical impedance spectroscopy (EIS) of PPy samples revealed 1.3 times higher ion conductivity of PPy-PEO films in PC solvent. Scanning electron microscopy (SEM) was used to investigate morphologies of PPy samples, and EDX spectroscopy was conducted to determine ion contents of oxidized/reduced films.
| S-EPMC8781785 | biostudies-literature
Project description:In recent decades, significant research efforts have been devoted to studying various types of actuators. Of particular interest are soft actuators based on electroactive polymers, which offer low operating voltage, light weight, and fast response. In this study, we demonstrate the feasibility of a soft linear actuator fabricated from polypyrrole (PPy), an electroactive polymer that is easy to synthesize, cost-effective, and biocompatible. By optimizing the polymerization conditions, the operation condition and environment, we were able to achieve improved and stable actuator performance. Furthermore, we developed a new actuator-contained component with a flexible counter electrode to build an actuator that operates in air. This approach enabled us to build small and lightweight actuators that operate in air, with a diameter of 5 mm, resembling artificial muscles. Our resulting miniaturized and integrated linear PPy-based actuators can be driven at low voltages (±1.5 V), making them suitable for use in various parts of the body. As such, this actuator holds significant potential for a wide range of applications in the fields of soft electronics, drug delivery, artificial organs, and muscles, as well as a component material for portable medical sensors and devices.
| S-EPMC10459993 | biostudies-literature
Project description:Conducting polymers (CP) have shown great features in building textile actuators. To date, most of the yarn-based or CP-yarn actuators have been operated in liquid electrolytes in a three-electrode-cell configuration, comprising an external counter and a reference electrode. For integration in textiles, a two-electrode system is needed, where both electrodes are in a yarn format. This can be achieved by having two CP-yarns, where one acts as the anode and the other as the cathode. For these two CP-yarns to operate synchronically, they both need to expand (or contract) during opposite reactions. This can be achieved by doping one CP-yarn with mobile anions that will expand during oxidation, while the other CP-yarn should be doped with immobile anions expanding during reduction. As a result, the same movement is created upon opposite redox reactions, both collaborating with the actuation in the same direction without the need for an external passive electrode to close the electrical circuit, which could oppose or hinder the movement. Most of the studies on textile actuators are based on cation-driven CP-yarn actuators, while little is known about anion-driven systems in CP-yarn actuators. Here, we first present a study of the effect of the dopants, solvents, and polymer layer combinations on the mechanism and strain of CP-yarns. The CP-yarns are coated with two layers: an inner poly(3,4-ethylenedioxythiophene) (PEDOT) layer and the outer and active polypyrrole (PPy) layer. According to our results, the dopant of the inner PEDOT layer seems to affect the actuation mechanism of the outer PPy layer and, thereby, of the whole CP-yarn actuator, influencing the direction of the movement and enhancing or hindering the total strain of the actuator. We show that a CP-yarn coated with PEDOT(Tos)/PPy(ClO4) and actuated in LiClO4 aqueous solution showed a pure anion-driven actuation. Next, based on the latter results, we demonstrate for the first time the dual actuation of two CP-yarns, doped with two different dopants, ClO4 - and DBS-, actuating simultaneously driven by opposite redox reactions and exhibiting an average of 0.5% of strain, an important step toward in-air actuating yarns.
| S-EPMC11467901 | biostudies-literature
Project description:The emerging field of soft robotics often relies on soft actuators powered by pressurized fluids to obtain a variety of movements. Strategic incorporation of soft actuators can greatly increase the degree of freedom of soft robots thereby bestowing them with a range of movements. Balloon actuators are extensively used to achieve various motions such as bending, twisting, and expanding. A detailed understanding of how material properties and architectural designs of balloon actuators influence their motions will greatly enable the application of these soft actuators. In this study, we developed a framework involving experimental and theoretical analyses, including computational analysis, delineating material and geometrical parameters of balloon actuators to their bending motions. Furthermore, we provide a simple analytical model to predict and control the degree of bending of these actuators. The described analytical tool could be used to predict the actuating function of balloon actuators and thereby help generate optimal actuators for functions which require control over the extent and direction of actuation.
| S-EPMC9528995 | biostudies-literature
Project description:Currently, a straightforward fabrication technique for the development of soft actuators to explore their potential in robotic applications using environmentally compatible raw materials represents an important challenge. A conventional conducting polymer, such as polypyrrole (PPy), shows promising conductivity for such applications. This study presents the synthesis of PPy/polyvinyl alcohol (PPy/PVA)-based ion exchange polymer films containing PEDOT:PSS/SWNT/IL electrodes that undergo conformational changes in response to the applied voltage. Four types of ionic polymer actuator films with different sizes of PPy nanoparticles were fabricated to investigate the size-dependent electromechanical actuation performance. The aim of this study is to design and develop a stable, flexible, and reliable film actuator for robotic applications. Scanning electron microscopy and transmittance electron microscopy were performed to observe the surface morphology and detailed structure of the fabricated actuator films. The current density and ionic conductivity are demonstrated by the cyclic voltammogram and linear sweep voltammogram, respectively. The enhanced values of the water uptake, ion exchange capacity and ionic conductivity of the PPy/PVA polymer composite films enhanced the electrical properties and the tip deflection performance as compared to those of the other reported expensive perfluorinated polymer-based membrane actuators. A two finger-based micro gripping device was also developed, in which both the fingers were made up of the O-PPy/PVA/EL-based ion exchange polymer films. This mechanically stable and flexible film actuator fabricated via a synergistic combination of PPy/PVA composition containing PEDOT:PSS/SWNT/IL electrode surfaces possesses a substantial potential as an actuator material for micro robotic applications.
| S-EPMC9076173 | biostudies-literature
Project description:Electromechanical coupling defines the ratio of electrical and mechanical energy exchanged during a flexure cycle of a piezoelectric actuator. This paper presents an analysis of the dynamic electromechanical coupling factor (dynamic EMCF) for cantilever based piezoelectric actuators and provides for the first time explicit expressions for calculation of dynamic EMCF based on arrangement of passive and active layers, layer geometry, and active and passive materials selection. Three main cantilever layer configurations are considered: unimorph, dual layer bimorph and triple layer bimorph. The actuator is modeled using standard constitutive dynamic equations that relate deflection and charge to force and voltage. A mode shape formulation is used for the cantilever dynamics that allows the generalized mass to be the actual mass at the first resonant frequency, removing the need for numerical integration in the design process. Results are presented in the form of physical insight from the model structure and also numerical evaluations of the model to provide trends in dynamic EMCF with actuator design parameters. For given material properties of the active and passive layers and given system overall damping ratio, the triple layer bimorph topology is the best in terms of theoretically achievable dynamic EMCF, followed by the dual layer bimorph. For a damping ratio of 0.035, the dynamic EMCF for an example dual layer bimorph configuration is 9% better than for a unimorph configuration. For configurations with a passive layer, the ratio of thicknesses for the passive and active layers is the primary geometric design variable. Choice of passive layer stiffness (Young's modulus) relative to the stiffness of the material in the active layer is an important materials related design choice. For unimorph configurations, it is beneficial to use the highest stiffness possible passive material, whereas for triple layer bimorph configurations, the passive material should have a low stiffness. In all cases, increasing the transverse electromechanical coupling coefficient of the active material improves the dynamic EMCF.
| S-EPMC6189939 | biostudies-other
Project description:The locomotion of soft snake robots is dependent on frictional interactions with the environment. Frictional anisotropy is a morphological characteristic of snakeskin that allows snakes to engage selectively with surfaces and generate propulsive forces. The prototypical slithering gait of most snakes is lateral undulation, which requires a significant lateral resistance that is lacking in artificial skins of existing soft snake robots. We designed a set of kirigami lattices with curvilinearly-arranged cuts to take advantage of in-plane rotations of the 3D structures when wrapped around a soft bending actuator. By changing the initial orientation of the scales, the kirigami skin produces high lateral friction upon engagement with surface asperities, with lateral to cranial anisotropic friction ratios above 4. The proposed design increased the overall velocity of the soft snake robot more than fivefold compared to robots without skin.
| S-EPMC9110809 | biostudies-literature