Fabrication Of Ionic Polymer Metal Composite Research Articles

Graphene Oxide-Polyaniline Coating on Ionic Polymer Blend Membrane for Actuation

Ionic polymer metal composites (IPMC) can be used as actuators and sensors and intrinsically have low activation voltage and large bending strain, which help to transform electrical energy to mechanical energy and can be utilized as bidirectional material. In this study, the ionic polymeric blend films/membranes of PVDF:PSSS:PVP in the blend ratio of 40:30:30; 50:30:20 and 60:15:25 (wt.%) is presented. The membranes were prepared by solution cast technique and coated with graphene oxide (GO)-polyaniline (PANI). Membranes were characterized by X-ray diffraction, optical microscopy. Electrical conductivities at different frequencies and water uptake properties were also determined. The actuating performance of PVDF:PSSS:PVP and water uptake of blend membrane was found to be maximum for the blend ratio of 60:15:25. PVDF:PSSS:PVP with blend ratio (60:15:25) also exhibited highest actuation at 10 V DC. Graphene oxide was prepared and characterized by using FTIR and Raman spectra. A brief account of the fabrication of IPMC and its actuation application was also presented.

Enhanced actuation application of nafion–ZnO nanoparticles doped sheet as ionic polymer metal composite (IPMC); dopant piezoelectric effect

In this paper, a novel ionic polymer metal composite (IPMC) has been fabricated by chemical electroless plating method integrated with doping ZnO nanoparticles in the nafion polymeric matrix. This IPMC is a smart material acting as a responsive actuator in biomedical devices. ZnO nanoparticles, known as remarkable piezoelectric material, could highly enhance the actuation properties of our IPMC. Fourier transform infrared (FTIR) microscopy analysis, scanning electron microscopy (SEM) imaging, photoluminescence (PL) spectroscopy and XRD spectroscopy were used to analyse ZnO nanoparticles. Doped sheet fabrication was also proved by X-ray scattering. The final IPMC fabrication was done by chemical electroless plating of Pt on the doped sheet as electrodes. Angle of bending of the undoped and ZnO-doped IPMC was measured in an applied electrical field as a function of actuating properties. It was found that ZnO doping could increase the actuation application up to 42% in the same applied voltages.

Soft actuator based on Kraton with GO/Ag/Pani composite electrodes for robotic applications

In this work, electrochemically-driven Kraton/graphene oxide/Ag/polyaniline (Kraton/GO/Ag/Pani) polymer composite based ionic polymer metal composite (IPMC) was fabricated as a soft actuator. Silver nanopowder with polyaniline coating used as an electrode material is a novel approach in the fabrication of IPMC, which gives new opportunities for development of the electrode on ionic polymer actuator surfaces directly without electroless plating of Pt or Au metal. The Kraton/GO/Ag/Pani membrane showed much higher water-uptake (WU), ion exchange capacity (IEC), proton conductivity than those of several reported IPMC membranes. The enhanced actuation performance indicates that the Kraton/GO/Ag/Pani is a better alternative to the highly expensive commercialized IPMC actuator.

Humidity sensor based on the ionic polymer metal composite

In this paper, a novel method for fabrication of an ionic polymer-metal composite (IPMC)-based humidity sensor is developed and optimized. IPMC is a kind of smart material that can work as a sensor or an actuator in wet environments or liquids. Poor adhesion between electrodes and the polymer and peeling off phenomenon are common problems in IPMC fabrication. Mechanical roughening, plasma treatment of the polymer surface and sputtering a thin layer of Ti and Cr as adhesion layers between polymer and Au electrodes are proposed to solve these issues. Different fabricated IPMC electrodes were then used as a capacitor to measure the relative humidity variations at different deflections and relative humidity conditions and the results have been compared. Our results show that IPMC using Au with 990nm thicknesses worked properly and a sensitivity value of 13.43% was achieved.

Replacement of surface roughening using polyvinyl alcohol coating in the fabrication of nafion-based ionic polymer metal composite (IPMC) actuators

In this paper, we propose a new fabrication method for ionic polymer metal composite (IPMC) actuators using a Nafion/Polyvinyl alcohol layer coating instead of conventional surface roughening (sandblasting) to achieve good adhesion of a Pt electrode. Compared with the Nafion membrane, the proposed membranes (NNP25 and NNP50) have increased mechanical properties (tensile strength and Young’s moduli). In addition, IPMCs using the proposed membranes had lower current densities than the Nafion-based IPMC. Therefore, compared with the Nafion-based IPMC, the proposed NNP25- and NNP50-based IPMCs had higher blocking forces, but lower tip displacements. Consequently, through the proposed simple procedure and cost-effective fabrication method using a Nafion/Polyvinyl alcohol layer coating, we can fabricate that the proposed IPMC actuators have enhanced mechanical properties in comparison with the sandblasting surface roughening used in the conventional IPMC fabrication method.

Reliability tests of ionic polymer metallic composites in dry air for actuator applications

Electroactive polymers (EAPs) are capable of exhibiting large shape changes in response to electrical stimulation. EAPs can produce a large deformation with a low applied voltage for actuation applications. The IPMC (Ionic Polymer Metal Composite) is a well-known type of ionic EAP. It has numerous attractive advantages, such as low electrical energy consumption and being lightweight. The underlying mechanism of an IPMC actuator is the ionic diffusion when a voltage gradient is applied. As such, the characteristics of the ionic solution have a large impact on the physical properties of the IPMC. In this paper, reliability tests of IPMCs with a non-aqueous ionic solution are demonstrated. The Pt-IPMC with LiOH aqueous solution exhibits the best maximum displacement, but the water in the LiOH solution is electrolyzed easily because of the low electrolysis voltage (1.23V) of water. To ameliorate the electrolysis problems and improve the operation time, more appropriate solvents with a high electrolysis voltage and low vapor pressure should be chosen. Parylene-coating can also protect the IPMC from solvent loss. The reliability tests focus on the durability of IPMCs in dry air. Improvements in IPMC fabrication, such as Ag-IPMC, are discussed in this paper. Through the use of parylene protection and an ionic solution with a high electrolysis voltage, the lifetime of the Ag-IPMC in dry air is up to 15 times greater than that of the uncoated Ag-IPMC with aqueous solution. We have addressed potential issues regarding the dry air actuation of IPMCs, and found that the cracking of electrodes has a major impact on the reliability of the IPMCs in this study.

Ionic polymer metal composites with polypyrrole-silver electrodes

Ionic polymer metal composites (IPMCs) are a class of soft active materials that are finding increasing application in robotics, environmental sensing, and energy harvesting. In this letter, we demonstrate the fabrication of IPMCs via in-situ photoinduced polymerization of polypyrrole-silver electrodes on an ionomeric membrane. The composition, morphology, and sheet resistance of the electrodes are extensively characterized through a range of experimental techniques. We experimentally investigate IPMC electrochemistry through electrochemical impedance spectroscopy, and we propose a modified Randle's model to interpret the impedance spectrum. Finally, we demonstrate in-air dynamic actuation and sensing and assess IPMC performance against more established fabrication methods. Given the simplicity of the process and the short time required for the formation of the electrodes, we envision the application of our technique in the development of a rapid prototyping technology for IPMCs.

A review on IPMC material as actuators and sensors: Fabrications, characteristics and applications

In this paper we present a comprehensive review of ionic polymer metal composite (IPMC) covering fundamentals of IPMC; from fabrication processes to control and applications. IPMC is becoming an increasingly popular material among scholars, engineers and scientists due to its inherent property of low activation voltage, large bending strain, i.e., transformation electrical energy to mechanical energy, and properties to be used as bidirectional material, i.e., it can be used as actuators and sensors. Among the diversity of electro active polymers (EAPs), recently developed IPMCs are good candidates for use in bio-related application because of their biocompatibility. Yet, the challenge remains in controlling a somewhat complicated material as mechanical, electrical and chemical properties interact with each other in the ionic polymer. Several IPMC fabrication processes, their mechanical characteristics and performance, a number of recent IPMC applications and pertaining mathematical modeling have been reported in this paper. Also we have attempted to present concisely the control of IPMC and effects of various factors in the performance of IPMC. The applications of IPMC have been growing, and recently more sophisticated IPMC actuator applications have been performed. This indicates that the IPMC actuators hold potential for more sophisticated control application. Extensive references are provided for more indepth explanation.

Fabrication and Thermo-Mechanical Analysis of Pure Silver-Electrode Ionic Polymer-Metal Composite (IPMC) Actuator

Till to date, fabrication of Ionic Polymer-Metal Composites (IPMC) are carried out successfully using noble metal such as platinum/gold as the surface electrode. In this work we have proposed cost effective fabrication method for IPMC actuator using non-precious metal electrode of silver (Ag). Chemical decomposition method is followed using Nafion as the ion exchange membrane to fabricate pure Ag-electrode IPMC. Microscopic and morphological analyses reveal that, silver particles penetrate well through the surface of Nafion membrane. The bending deformation measurement and analysis of the thermo-mechanical properties of the fabricated IPMC is carried out. The experiment results and performance of the IPMC actuator confirm that the fabrication of pure Ag-IPMC is feasible and can be used as artificial muscle material.

Force optimization of ionic polymer metal composite actuators by an orthogonal array method

Ionic polymer metal composites (IPMCs), a new kind of electro-active polymer, can be used for micro robotic actuators, artificial muscles and dynamic sensors. However, IPMC actuators have the major drawbacks of a low generative blocking force and dependence on a humid environment, which limit their further application. Multiple process parameters for the fabrication of IPMCs were optimized to produce a maximum blocking force; the parameters included reducing agent concentration, platinum salt concentration in the initial compositing process, and tetraethyl orthosilicate (TEOS) content. An orthogonal array method was designed and a series of fabrication experiments were carried out to identify the optimum process parameters. The results show that the platinum salt concentration in the initial compositing process plays the most significant role in improving the blocking force of IPMCs, the TEOS content plays an important role, and the reducing agent concentration has no apparent effect on the blocking force. In the optimized conditions, the IPMC actuator exhibited maximum blocking force of 50 mN, and the corresponding displacement was 14 mm. Compared with normal conditions, the blocking force improved 2.4-fold without sacrificing the displacement, and the effective air-operating life was prolonged 5.8-fold for the blocking force and 5-fold for the displacement. This study lays a solid foundation for further applications of IPMCs.

Fabrication of ionic polymer-metal composites (IPMCs) and robot design

This paper describes a method for preliminary manufacturing experiments on a type of smart materials-ionic polymer-metal composites (IPMCs). They belong to EAP materials and are famous for their capability of huge displacement within a low voltage (1−3 V). With best operation quality in the humid environment, they can be made as underwater robots in simple structures. In this paper, two purposes are embodied. One focuses on the research on the IPMCs characteristics, including the actuating principle, manufacturing process, and parameters of performance. The other is that a relevant robot driven by IPMCs strips is designed. According to imitation propulsion mechanism of undulatory fins, IPMCs are designed for a novel bionic water vehicle propelled by undulatory multiple fish-like fins (made by IPMCs). The robot consists of three fins on the bottom tightly contacting by plastic foils with each other.

A novel design and fabrication of multilayered ionic polymer-metal composite actuators based on Nafion/layered silicate and Nafion/silica nanocomposites

Recently, we prepared Nafion/layered silicate and Nafion/silica nanocomposites and used them as starting materials in the fabrication of ionic polymer-metal composites (IPMCs). Experimental data indicated that Nafion/silica-based IPMCs exhibited almost three times higher blocking force with 200% larger displacement than the pure Nafion-based IPMC. On the other hand, due to the barrier property of well-dispersed silicate platelets, the response rate of Nafion/layered silicate-based IPMCs under an electric voltage was lower than that of Nafion-IPMC. However, these samples showed a complete lack of relaxation, which appeared to be a good sign of a prolonged service life of IPMC. In this work, the high blocking force and the lack of relaxation during operation period observed, respectively, for Nafion/silica- and Nafion/layered silicate-based IPMCs were combined in a multilayer configuration, which contained a main Nafion/silica nanocomposite layer sandwiched between two outer layers of Nafion/layered silicate nanocomposites. Two designs for multilayered IPMCs were proposed. In the first design, the electrode layer of IPMCs was prepared by a conventional electroless plating process, while in the second design a flexible electrode layer was made by recasting of a mixture containing Nafion solution, layered silicate and a conductive material (e.g. Ag nano-powder). The multilayered IPMC exhibited a greatly improved blocking force with a very limited relaxation. The IPMC of the second design showed a blocking force of 6 and 9 g f at 2 and 3 V dc, respectively. A remarkable improvement in tip displacement of IPMC was also obtained, where multilayered IPMCs demonstrated a 250% increase in tip displacement compared to that of Nafion-IPMC. Furthermore, the response rate of multilayered IPMCs was also higher than that of conventional Nafion-based IPMC. Results and highlights of our present study are presented in this paper.

A novel fabrication of ionic polymer-metal composites (IPMC) actuator with silver nano-powders

This article reports a novel approach of applying silver nano-powders to the fabrication of ionic polymer-metal composites (IPMC) actuator with good adhesion between the metal electrodes and polymer membrane without surface roughening pretreatment at low cost, high repeatability and short processing time. Micro-fabrication technologies are used for this IPMC actuator fabrication including the dissolving and casting of silver nano-particles (35nm) in Nafion® diluted solution, followed embossing, nontoxic electroless plating of silver, and microelectroforming of nickel. This IPMC actuator exhibits large deformation of bending curvature angle of more than 90° at lower driving voltage of 3V. The frequency response of displacement with applied AC voltage of 2V at 1Hz results in a regular periodic deformations of the IPMC actuator. The elasticity modulus of the IPMC actuator can be reduced using an Ag–Nafion electrode for larger deformation than a pure Ag metal electrode. The electronic active polymer, IPMC, could be potentially used as the actuator of the active guide-wire, effective biomimetic sensor and artificial muscles.