Application Of Ionic Polymer Metal Composites Research Articles

Preparation and performance analysis of Pt-IPMC for driving bionic tulip

Based on the biological characteristics of tulip, the low driving voltage and fast response of ionic polymer metal composite (IPMC), we analyzed the fabrication, morphology and performance of the platinum IPMC (Pt-IPMC) and selected the right IPMC for driving bionic tulip. The preparation and performance of IPMC was analyzed first in this paper such as blocking force, output displacement and bending angle of IPMC under the different directed current voltage (DC). The optimal IPMC sample size and driving voltage were selected based on tulip blooming angles and the strain energy density of IPMC, which completed the blooming process of bionic tulip. The feasibility of IPMC used in driving bionic field was fully proved in this paper, which laid a foundation for the application of IPMC in driving biomimetic biological robots.

Electroless copper deposition and interface characteristics of ionic electroactive polymer

In this study, the cheap copper electrode ionic polymer metal composite (IPMC) was prepared by chemical deposition. The formation mechanism of the copper electrode layer was analyzed firstly, then the surface and cross section morphology, roughness and porosity of IPMC were measured, and the interface profile was simulated and predicted based on Weierstrass-Mandelbrot (WM) function, at last, the adhesion force of the interface was calculated. The results show that the coarsening of Nafion and the adsorption of Ag+ ions provide a good catalytic activation site for the nucleation and rapid growth of copper particles. The copper layer on the surface of IPMC is arranged in granular, distributed compactly and uniformly, with the porosity of 52.3% and a strong (111) preferred orientation, which are beneficial to the performance of IPMC. Based on the WM function, the fractal dimension, characteristic scale and characteristic roughness are used to reflect the flatness and complexity of surface profile. The adhesive strength between the substrate and the coating is mainly due to the surface force field caused by the coarsening treatment. The theoretical and simulation studies of the interface characteristics are helpful to understand the internal mass transfer mechanism of IPMC and characterize the complex interface morphology, which also lays a foundation for the later research and application of IPMC.

Property of ionic polymer metal composite with different thicknesses based on solution casting technique

As an ionic electroactive polymer, ionic polymer metal composite (IPMC) has unique advantages and is widely used in various fields. However, the output force of IPMC is small, which further limits the application of IPMC. In this study, the Nafion520cs were selected as the preparation solution, and three ion-exchange polymer membranes (IEPMs) with different thicknesses (158, 256 and 383 [Formula: see text]m) were designed and prepared successfully by solution casting technique to study the output force. Then, three platinum electrodes-IPMCs (Pt-IPMCs) were fabricated using electroless plating method. The properties of Pt-IPMCs in terms of morphology, displacements and blocking forces were then evaluated under direct current voltage. The results showed that the prepared ionic membranes were uniform, transparent and flat, without accumulation or bubble. The platinum particles were preferably deposited on the surface, which promoted delivery of current through the IPMCs under the applied voltage, and improved the actuation performance. With the increase of voltage, the maximum displacement and maximum blocking force of the three IPMCs increased first and then decreased. When the voltage is 5.5 V, the maximum displacement for 158 um is 26 mm, while the maximum blocking force of 10.74 mN appears at 6.5 V for 383 um. It is necessary to select suitable thickness of IPMCs to adapt to different working environment and field, which provides a strong basis for further application of IPMCs.

Actuation Modeling of Ionic–Polymer Metal Composite Actuators Using Micromechanics Approach

Herein, the movement of hydrated cations in ionic–polymer metal composite (IPMC) is analyzed by the micromechanics method. Based on the mechanism of IPMC, the migration of hydrated cations is in a step‐by‐step order, and the aggregation of hydrated cations on the cathode side results in the bending of IPMC toward the anode. The physical models of the maximum displacement and maximum blocking force of IPMC are established, the Pt IPMCs are prepared by chemical deposition, and the calculated values are compared with the experimental values. The results indicate that there is water electrolysis in the actuation process of IPMC, which inhibits the migration of ions on the electrode surface and has a negative effect on the property of IPMC. By comparing the calculated value of the model with the experimental value, it is found that there is good consistency. The mathematical statistical metrics, mean absolute error, mean relative error, determination coefficient, correlation coefficient, mean square error, root mean square error, and relative root mean square error, are used to assess the model capability, which puts a theoretical foundation for the prediction and simulation of IPMC and promotes the further development and practical application of IPMC.

Property of Nafion-ionic polymer-metal composites based on Mori–Tanaka methodology and gradient mechanics

Ionic polymer-metal composite (IPMC) actuators are a class of electroactive polymer composites that exhibit some interesting electromechanical characteristics such as low voltage actuation, large displacements, and benefit from low density and elastic modulus. Elastic modulus and surface resistance are basic properties of IPMCs that play a role in almost all practical applications of these materials. The prediction of the elastic modulus and surface resistance is of extreme importance to better grasp the mechanical behavior of IPMCs and to evaluate the success of the design. This paper has proposed a theoretical framework for predicting the elastic modulus and surface resistance of copper electrodes IPMCs. A five layers analytical assemblage model is introduced for the IPMCs relied upon improved classical lamination theory. The depositional metallic atoms were used as the exterior layer, the ionic polymer was used as the middle layer, and the material between the two layers was a gradient layer. Based on Mori–Tanaka methodology and gradient mechanics, the overall elastic properties of composites are obtained and lie between those obtained from the experiment. The prediction showed a good agreement with the experimental elastic modulus values with a maximum deviation of less than 10%. The overall results have provided useful insight into the elastic modulus and surface resistance effects to the properties of the IPMC. This would open further opportunities toward the higher application of IPMC.

The square rod-shaped ionic polymer-metal composite and its application in interventional surgical guide device

ABSTRACT Ionic polymer-metal composite (IPMC) is an electro-active polymer material, which has many advantages such as small size, light weight, low driving voltage, large strain, and good biocompatibility. However, the conventional sheet IPMC has the shortcoming of only bending in the two-dimensional plane, which greatly limits the application of IPMC in the field of interventional surgery. In this work, a square rod-shaped IPMC with multi-degree-of-freedom motion was fabricated, and the displacement and blocking force of the square rod-shaped IPMC in different directions are measured and analyzed under the DC voltage signal. An interventional catheter was designed using the square rod-shaped IPMC in order to achieve active guidance, and a simulation experiment platform and a model of human aorta were built to successfully complete the in vitro simulation experiment of interventional surgery, which preliminarily verified the feasibility of the square rod-shaped IPMC in the field of interventional surgery.

Low-order Nonlinear Finite-Impulse Response Soft Sensors for Ionic Electroactive Actuators Based on Deep Learning

This paper introduces a soft sensor (SS) for the estimation of the deflection of a polymeric mechanical actuator. The actuator is based on ionic polymer-metal composites (IPMCs). Applications of IPMCs have been proposed in fields such as robotics, surgery, and aerospace, to mention the most interesting ones. In such application fields, both the complexity and the size of the actuating system are of chief importance. An SS can be, therefore, preferred to hardware measuring the actuator output, for estimating the actuator motion. Also, low-order models are of interest to limit the computational load, which can be a constraint in real-time applications. To this aim, several data-driven nonlinear finite-impulse response (NFIR) models have been investigated. Data, used for the model identification, have been acquired, in controlled environmental conditions, by using swept signals as the input to the IPMC actuator. Linear and nonlinear models, based on principal component analysis, shallow, and deep neural networks (NNs), have been investigated, for different model orders. The best results have been obtained by an SS based on a fifth-order NFIR model, implemented by a deep belief NN.

Behavior Identification of IPMC Actuators Using Laguerre-MLP Network With Consideration of Ambient Temperature and Humidity Effects on Their Performance

In this paper, we propose a model for ionic polymer metal composite (IPMC) actuators that its superiority over the other models is its capability to make a confident prediction about the bending displacement of all points along the IPMC strip in large bending displacements, without using previous data of the output and also with consideration of the effects of the ambient conditions on its performance. To achieve this aim, we used a nonautoregressive model named as Laguerre-multilayer perceptron network. Moreover, the effect of ambient temperature and humidity changes in the range of biomedical applications of IPMC was investigated using variance analysis of experimental data and also these ambient conditions were applied to the proposed model as operating points. This model was described in detail and validated by experimental results.

Improve the Performance of Mechanoelectrical Transduction of Ionic Polymer-Metal Composites Based on Ordered Nafion Nanofibres by Electrospinning.

An ionic polymer–metal composite (IPMC) is a kind of soft material. The applications of IPMC in actuators, environmental sensing, and energy harvesting are currently increasing rapidly. In this study, an ordered Nafion nanofibre mat prepared by electrospinning was used to investigate the characteristics of the mechanoelectrical transduction of IPMC. The morphologies of the Nafion nanofibre mat were characterized. The proton conductivity, ion exchange capacities, and water uptake potential of the Nafion nanofibre mat were compared to traditional IPMC, respectively. A novel mechanism of Nafion nanofibre IPMC was designed and the open circuit voltage and short circuit current were measured. The maximum voltage value reached 100 mv. The output power was 3.63 nw and the power density was up to 42.4 μW/Kg under the load resistance. The Nafion nanofibre mat demonstrates excellent mechanoelectrcical transduction behavior compared to traditional IPMC and could be used for the development of self-powered devices in the future.

Adaptive observer-based control for an IPMC actuator under varying humidity conditions

As ionic polymer metal composites (IPMC) are increasingly applied to mechatronic systems, many new IPMC modeling efforts have been reported in the literature. The demands of rapidly growing technology has generated interest in advancing the intrinsic actuation and sensing capabilities of IPMC. Classical IPMC applications need constant hydration to operate. On the other hand, for IPMCs operating in air, the water content of the polymer varies with the humidity level of the ambient environment, which leads to its strong humidity-dependent behavior. Furthermore, decreasing water content over time plays a crucial role in the effectiveness of IPMC. Therefore, the primary challenge of this work is to accurately model this phenomenon. The principal contribution of the paper is a new IPMC model, which considers the change of moisture content. A novel nonlinear adaptive observer is designed to determine the unknown electric potential and humidity level in the polymer membrane. This approach effectively determines the moisture content of the IPMC during long-term continuous operation in air. This subsequently allows us to develop an effective back-stepping control algorithm that considers varying moisture content. Data from experiments are presented to support the effectiveness of the observation process, which is shown in illustrative examples.

A moisture and electric coupling stimulated ionic polymer-metal composite actuator with controllable deformation behavior

Ionic polymer-metal composite (IPMC) actuator can generate large and rapid deformation based on ion migration under a relatively low driving voltage. Under full hydrated conditions, the deformation is always prone to relaxation. At room humidity conditions, the deformation increases substantially at the early stage of actuation, and then decreases gradually. Generally, most researchers considered that the change of water content or relative humidity mainly leads to the deformation instabilities, which severely limits the practical applications of IPMC. In this Letter, a novel actuation mode is proposed to control the deformation behavior of IPMC by employing moisture as an independent or collaborative incentive source together with the electric field. The deformation response is continuously measured under electric field, electric field-moisture coupling stimulus and moisture stimulus. The result shows that moisture can be a favorable driving factor for IPMC actuation. Such an electric field-moisture coupling stimulus can avoid the occurrence of deformation instabilities and guarantee a superior controllable deformation in IPMC actuation. This research provides a new method to obtain stable and large deformation of IPMC, which is of great significance for the guidance of material design and application for IPMC and IPMC-type iEAP materials.

Searching for a new ionomer for 3D printable ionic polymer–metal composites: Aquivion as a candidate

The work presented in this paper introduces Aquivion as a potential candidate for additive manufacturing of ionomeric polymers for the application of IPMCs. First, Aquivion was characterized and compared with Nafion to show that it has the similar qualities, with the major difference being the ionic conductivity. Ionic polymer–metal composites (IPMCs) were fabricated using off-the-shelf membranes of Nafion and Aquivion. The actuation tests showed improved performance for an IPMC with Aquivion as the base compared to an IPMC with a Nafion base. With these results in mind, additive manufacturing of unique shapes using Aquivion filament was studied. A 3D printer was modified to work with Aquivion filament and the polymer was printed into various shapes. Using the printed membranes, IPMCs were fabricated using an electroless plating process. Nafion-based and printed Aquivion-based IPMCs were tested for their performance in back relaxation, frequency driven actuation, blocking force, and mechano-electric sensing. The printed Aquivion-based IPMCs performed comparably to Nafion-based IPMC in back relaxation and showed significantly improved performance in frequency driven actuation, blocking force generation, and mechano-electric sensing.

Robust tracking control of an IPMC actuator using nonsingular terminal sliding mode

Ionic polymer metal composite (IPMC) is a highly innovative material that has recently gained attention in many fields such as medical, biomimetic, and micro/nano underwater applications. The main characteristic of IPMC lies in its ability to achieve a large deflection under a fairly low driving voltage. Moreover, its agile, light weight, noiseless and flexible features render it well suited for certain specific applications. Like other smart materials, such as piezoelectric ceramics, IPMC could be used in actuators or sensors. In this paper, we study the application of IPMC as an actuator for underwater use. The goal is to develop a robust feedback controller for the IPMC actuator to track a desired reference whilst dealing with the uncertainties due to the inherent actuator nonlinearity, external disturbance or the variations of working environment. To this end, we first present a nominal model of the IPMC actuator through experimental identification. Next, a nonsingular terminal sliding mode controller is proposed. Lastly, experimental studies are conducted to verify the tracking accuracy and robustness of the designed controller.

Nonautoregressive Nonlinear Identification of IPMC in Large Deformation Situations Using Generalized Volterra-Based Approach

Ionic polymer metal composites (IPMCs) are special smart materials that are biocompatible and can be used in biomedical and industrial applications. Using previous samples of a system output in a model (autoregressive models) is not feasible in dominant applications of IPMCs especially in biomedical applications. In this paper, we present a generalized Volterra-based model to achieve a nonautoregressive, nonparametric, and nonlinear identification of IPMC. The significant superiority of this approach is its capability to nonautoregressive identification of both linear and nonlinear behaviors of IPMC actuators even in large deformation situations.

Ionic polymer–metal composite applications

In this paper, the authors present a comprehensive review of ionic polymer–metal composites (IPMCs) covering their fundamentals, fabrication processes, characterization and applications. IPMCs are becoming increasingly popular among scholars, engineers and scientists due to their inherent properties of low activation voltage, large bending strain – that is, the transformation of electrical energy to mechanical energy – and properties to be used as a bidirectional material – that is, they can be used as actuators and sensors. Among the diversity of electroactive polymers, recently developed IPMCs are good candidates for use in biorelated applications because of their biocompatibility. The applications of IPMCs have been growing due to the progression in their manufacturing techniques, development of more accurate control models and recently demonstrated sophisticated IPMC actuator applications. This indicates that IPMC actuators hold potential for more sophisticated applications in control. Several recently reported IPMC fabrication processes, mechanical characteristics and performance and a number of recent IPMC applications have been reported in this paper. Extensive references are provided for a more in-depth explanation.

A Comprehensive Review of the Biomimetic Applications of Ionic Polymer Metal Composite

Bio-inspiration focuses on translating the evolutionary successes of natural species into engineering systems that mimic the geometry, function, and performance of the natural system. In this paper we present a latest comprehensive review of ionic polymer metal composite (IPMC) biomedical and biomimetic applications. IPMC is becoming an increasingly popular material among scholars, engineers and scientists due to its inherent properties of low activation voltage, large bending strain, flexibility, softness, suitable response time which make them a strong candidate to be applied as artificial muscle in biomimetic land and underwater applications. Among the diversity of electro active polymers (EAPs), recently developed IPMCs are good candidates for use in bio-related application because of their biocompatibility. Several recently reported IPMC biomimetic applications have been reported in this paper. The applications of IPMC have been growing due to progression in its manufacturing techniques, development of more accurate response models and control techniques, and recently more sophisticated IPMC actuator applications have been performed. This indicates that the IPMC actuators hold potential for more sophisticated and controlled applications in fields of biomedical and biomimetic. Extensive references are provided for more indepth explanation.

Aided manufacturing techniques and applications in optics and manipulation for ionic polymer-metal composites as soft sensors and actuators

AbstractRecently, ionic polymer-metal composites (IPMCs), which are becoming an increasingly popular material, have been used as soft actuators because of their inherent properties of light weight, flexibility, softness, especially efficient transformation from electrical energy to mechanical energy with large bending strain response under low activation voltage. This paper mainly focuses on a review on optical and micromanipulation applications of IPMCs as soft actuators. After presenting the general mechanism of sensing and actuating in IPMCs, recent progresses are discussed about the preparation process and practical technologies, especially for aided manufacturing techniques defined as the methods to fabricate IPMC into all kinds of shapes in terms of the demands, which are reviewed for the first time. Then, a number of recent IPMC applications for optical actuators, grippers and catheters are reviewed and investigated in this paper. Further developments and suggestions for IPMCs are also discussed. Extensive previous researches are provided for references in detail.

Bio-applications of ionic polymer metal composite transducers

Traditional robotic actuators have advanced performance which in some aspects can surpass that of humans, however they are lacking when it comes to developing devices which are capable of operating together with humans. Bio-inspired transducers, for example ionic polymer metal composites (IPMC), which have similar properties to human tissue and muscle, demonstrate much future promise as candidates for replacing traditional robotic actuators in medical robotics applications. This paper outlines four biomedical robotics applications, an IPMC stepper motor, an assistive glove exoskeleton/prosthetic hand, a surgical robotic tool and a micromanipulation system. These applications have been developed using mechanical design/modelling techniques with IPMC ‘artificial muscle’ as the actuation system. The systems are designed by first simulating the performance using an IPMC model and dynamic models of the mechanical system; the appropriate advanced adaptive control schemes are then implemented to ensure that the IPMCs operate in the correct manner, robustly over time. This paper serves as an overview of the applications and concludes with some discussion on the future challenges of developing real-world IPMC applications.

Forward Kinematic Modeling and Simulation of Ionic Polymer Metal Composites (IPMC) Actuators for Bionic Knee Joint

Ionic Polymer Composite Material (IPMC) is a flexible material and has revealed many advantages to encourage the scientists and researchers to investigate its characteristics for practical applications in various fields. The ongoing research can be divided into two branches. One deals with the improvement of the material properties to make it more useful and reliable while the other involves the exploration of new application areas. In this paper, Firstly, a new application of IPMC is suggested to actuate a rigid link that can mimic a bionic knee joint for a grass hopper manipulator. Secondly, forward kinematic model is proposed for the manipulator by employing geometric coordinate system method. Lastly, wolfram mathematica software is employed for the simulation of the model. The simulation results based on the model are found very encouraging to lure the article team to carry on the research idea for manufacturing and testing for the comparison of both types of results.

Mechanoelectric transduction in ionic polymer-metal composite

The ability of ionic polymer-metal composite (IPMC) to generate current on mechanical deformation, defined as mechanoelectric transduction, can be exploited for design and development of numerous sensors and energy harvesters. However, sensor application of IPMC is currently limited due to the lack of understanding of the transduction mechanism. This paper presents a physics-based mechanoelectric model that takes into account material properties, electrostatic phenomenon, and ion transport in the IPMC. Experimental verification of the model predictions is also reported.