IPMC Actuator Research Articles

Predicting simulation of flow induced by IPMC oscillation in fluid environment

This work deals with numerical modeling of fluid-structure interactions of a strip-shaped IPMC actuation in an aqueous environment. We consider an electro-chemo-mechanical model to predict the behavior of a strip-shaped IPMC actuation. The flow is predicted using the Navier–Stokes equations. The model is implemented and solved using the finite-element software COMSOL Multiphysics. Numerical simulations of the hydrodynamics induced by the strip-shaped IPMC are carried out for the purpose of novel propulsive actuators that interact with vortex flows to absorb their energy and release it at appropriate phase. The simulation results might be used to determine the effectiveness and application of IPMCs for micro-propulsion mechanisms, IPMC cilia-like structures used for flow actuation and mixing applications.

Active Tube-Shaped Actuator with Embedded Square Rod-Shaped Ionic Polymer-Metal Composites for Robotic-Assisted Manipulation.

This paper reports a new technique involving the design, fabrication, and characterization of an ionic polymer-metal composite- (IPMC-) embedded active tube, which can achieve multidegree-of-freedom (MODF) bending motions desirable in many applications, such as a manipulator and an active catheter. However, traditional strip-type IPMC actuators are limited in only being able to generate 1-dimensional bending motion. So, in this paper, we try to develop an approach which involves molding or integrating rod-shaped IPMC actuators into a soft silicone rubber structure to create an active tube. We modified the Nafion solution casting method and developed a complete sequence of a fabrication process for rod-shaped IPMCs with square cross sections and four insulated electrodes on the surface. The silicone gel was cured at a suitable temperature to form a flexible tube using molds fabricated by 3D printing technology. By applying differential voltages to the four electrodes of each IPMC rod-shaped actuator, MDOF bending motions of the active tube can be generated. Experimental results show that such IPMC-embedded tube designs can be used for developing robotic-assisted manipulation.

An attempt on manufacture of designable 3D shape IPMC actuator

An attempt on manufacture of designable 3D shape IPMC actuator

Electrochemical and electromechanical behavior of Nafion-based soft actuators with PPy/CB/MWCNT nanocomposite electrodes

In this work, as an alternative to precious platinum electrodes in IPMC actuators, PPy/CB/MWCNT electrode actuators were successfully fabricated by electropolymerization of PPy on both sides of the CB/MWCNT-coated Nafion membranes.

Patterning Method of IPMC Actuator Using a Milling Machining

A simple and low-cost patterning method is proposed for arbitrary undulatory motion of IPMC actuator. A commercial milling machine is used to provide desired pattern width and depth on surfaces of IPMC actuator. The copper tape is then used to connect electricity to electrode of patterned surfaces. The 2-segment patterned IPMC actuators are fabricated by combining electroless plating and milling machining which can provide precise patterning and control thickness of Platinum electrode layer. It is experimentally confirmed that the proposed patterned IPMC actuator produces undulatory motion as expected. The suggested method can easily be implemented into the IPMC actuator for various applications.

Torque Analysis of IPMC Actuated Fin of a Micro Fish like Device Using Two-Way Fluid Structure Interaction Approach

In this paper, a numerical simulation of three dimensional model of IPMC actuated fin of a fish like micro device is presented using two-way fluid structure interaction approach. The device is towed by the surface vessel through a tow cable. Fin is acting as dorsal fin of the fish to control depth of the device and also acts as a stabiliser against its roll motion. Fin's displacement disturbs water flow streamlines around it, as a result velocity and pressure profile of fluid's domain changes around the actuated fin. As fin's position continuously changes throughout its actuation cycle, this makes it transient structural problem coupled with a fluid domain. Fin's displacement is received by the fluid and resulting fluid forces are received by the fin making it a two-way fluid structure interaction (FSI) problem. Such problems are solved by multi field numerical simulation approach. This multifield numerical simulation is performed in ANSYS WORKBENCH by coupling transient structural and Fluid Flow (CFX) analysis systems. It is desirous to determine the torque acting on the fin due to fluid forces through its actuation cycle by IPMC actuators. The objective of this study is to develop the methodology (two-way fluid structural interaction (FSI)) used to simulate the transient FSI response of the IPMC actuated fin, subjected to large displacement against different flow speeds. Efficacy of fin as depressor and riser is also required to be judged by monitoring the forces acting on wing in response to its displacement under IPMC actuation. Same approach is also applicable to the self-propelled systems.

Dynamic Analysis of IPMC Actuated Fin of a Micro Fish Like Device

In this paper, a methodology is presented to perform dynamic analysis of structural linked mechanisms under true actuation cycle and force response of applied IPMC actuators. Dynamic analysis of a three link mechanism for fin actuation of a micro fish like device, towed by a surface vessel through tow cable, is performed through this methodology and same is applicable to other biomimetic robotic applications. Fluid (water) exerts a torque on IPMC actuated fin which is a function of fin's deflection and fluid flow velocity. Dynamic analysis is performed to assess the performance and efficacy of fin actuation mechanism under different loading conditions in terms of fin's deflection, velocity and acceleration. Actuation force is increased by increasing number of applied IPMC actuators of known actuation cycle and force generation response. Applied torque is determined by performing a numerical simulation of IPMC actuated fin against different flow velocities through two-way fluid structure interaction (FSI) approach. Numerical simulation is performed in ANSYS WORKBENCH to capture the complex hydrodynamic interactions between fin and fluid. Effect of increased actuation force against constant flow velocity (towing speed) and of increased flow velocity against constant actuation force are evaluated in terms of fin's deflection, velocity and acceleration. Finally, consequence of increasing the length of the link, connecting IPMC actuators and fin, are appraised for same actuation force and applied torque. Dynamic analysis is performed in Pro/ Mechanism, an advanced simulation tool. A technique of virtual prototyping through simulations is applied to access the performance of the fin actuation mechanism under true loading scenario before going into experimental phase, saving cost and time

Deflection Analysis of IPMC Actuated Fin of a Fish Like Micro Device

IPMC is used as artificial muscle in bioinspired micro structures/devices due to its low voltage actuation, high bending deformation, rapid response and capability to be operated in aqueous environment. In this paper, deflection analysis of IPMC actuated fin of a micro fish like device is presented to find out angle of attacks generated by IPMC deflection under different voltages applied to it. A novel approach is presented to perform motion analysis of IPMC actuated mechanisms for biomimetic robots under true actuation presentation of the IPMC actuator. This paper also contributes to present velocity and acceleration of the actuator at different voltages. Finally, two different configurations of the fin actuation mechanism are characterized in terms of angle of attack produced by them under same actuation responses of an IPMC actuator. Deflection analysis is performed in Pro/ Mechanism, an advanced simulation tool. A technique of virtual prototyping through simulations is applied to access the performance of both configurations of the fin actuation mechanism under true scenario before going into manufacturing.

Inverse Kinematic Analysis of Three Link Mechanism for Fin Actuation of Fish Like Micro Device

In this paper, inverse kinematic analysis of a proposed three link mechanism of a bio-inspired micro scanning device towed underwater by a surface vessel to actuate its aileron fins for its depth control and for its stabilization against roll is performed. Mechanism is actuated by IPMC actuators. To speed up the design verification process, computer aided simulations are used to perform motion analysis of the proposed IPMC actuated mechanism through Pro/Mechanism tool. Inverse kinematic analysis is performed to find out the joint variables of the mechanism to realize fin actuation along desired path. Displacements, velocities and accelerations of the links constructing mechanism are found out to establish their interrelationship. Results are analysed for the study of mechanism efficacy and for sizing the IPMC actuators. This paper contributes to introduce a new approach of virtual prototyping using advanced simulation tools for analysis and design verification of IPMC actuated mechanisms for biomimetic applications before moving into functional prototype stage.

IPMC actuators based on metal–Nafion™ composite films prepared by thermal decomposition of noble metal complexes

A simple and highly efficient compositing process was developed by synthesizing Pt or Pd nanoparticles embedded in polymers (Nafion™) with uniform distribution by in situ thermal decomposition of noble metal complexes. The homogenous mixtures of the metal complexes (trans-Pt(DMSO)(NH2CH2CH2OH)Cl2 or trans-Pd(DMSO)(H2NCH2CH2OH)Cl2) and Nafion™ dispersion went through a film casting process, and the metal ions in the Nafion™ were reduced to metal nanoparticles by the annealing process. The in situ compositing method avoids the use of excess metal sources and any external reducing agent/stabilizing agents, and leads to a uniform distribution of nanoparticles in the polymer matrixes. The films were characterized using optical microscopy and scanning electron microscopy. The actuation behavior in response to an AC electric field was investigated by bending displacements and blocking force measurements.

Forward Kinematic Analysis of IPMC Actuated Three Link Mechanism for Fin Actuation of Fish Like Micro Device

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. 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. In this paper, a new application of IPMC is proposed to actuate aileron fins of a micro scanning device towed underwater by a surface vessel to control its depth and to stabilize it against roll motion that can mimic pectoral fins of fish that steer them up and down by changing their angle of rotation and their dorsal fins that keep them upright against roll. Same is applicable for autonomous underwater vehicles. Secondly, a three link mechanism is presented to actuate aileron fin through IPMC actuator. Three dimensional model of the mechanism is developed in Pro-Engineer CAD software tool and its kinematic analysis is performed. Thirdly, forward kinematic model of proposed mechanism, based on geometric coordinate, is presented. Lastly, results of kinematic analysis of proposed mechanism are compared to that of model to verify its design and kinematics. Encouraging results decoy the research team to manufacture the mechanism and to perform experiments for its practical application.

The Study of Dynamic Characteristics of Selemion CMV-based IPMC Actuators in Humidity-Controlled Environments

The Study of Dynamic Characteristics of Selemion CMV-based IPMC Actuators in Humidity-Controlled Environments

Nonlinear dynamic modeling of ionic polymer conductive network composite actuators using rigid finite element method

Ionic polymer conductive network composite (IPCNC) 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. Thus, these emerging materials have potential applications in biomimetic and biomedical devices. Whereas significant efforts have been directed toward the development of IPMC actuators, the establishment of a proper mathematical model that could effectively predict the actuators’ dynamic behavior is still a key challenge. This paper presents development of an effective modeling strategy for dynamic analysis of IPCNC actuators undergoing large bending deformations. The proposed model is composed of two parts, namely electrical and mechanical dynamic models. The electrical model describes the actuator as a resistive-capacitive (RC) transmission line, whereas the mechanical model describes the actuator as a system of rigid links connected by spring-damping elements. The proposed modeling approach is validated by experimental data, and the results are discussed.

Dynamic model identification of IPMC actuator using fuzzy NARX model optimized by MPSO

In this paper, a novel inverse dynamic fuzzy NARX model is used for modeling and identifying the IPMC-based actuator’s inverse dynamic model. The contact force variation and highly nonlinear cross effect of the IPMC-based actuator are thoroughly modeled based on the inverse fuzzy NARX model-based identification process using experiment input-output training data. This paper proposes the novel use of a modified particle swarm optimization (MPSO) to generate the inverse fuzzy NARX (IFN) model for a highly nonlinear IPMC actuator system. The results show that the novel inverse dynamic fuzzy NARX model trained by MPSO algorithm yields outstanding performance and perfect accuracy.

Dynamic Modeling and Effect of Dehydration on Segmented IPMC Actuators Following Variable Parameter Pseudo-Rigid Body Modeling Technique

An ionic polymer-metal composite actuator has been analyzed following the variable parameters pseudo-rigid body modeling (VPPRBM) technique in order to assess the effect of dehydration on bending resistance and bending response. An experiment is conducted with a single patch IPMC actuator and the dehydration factor is obtained following the Cobb-Douglas production method. An energy-based dynamic model of the patches has been derived after developing the forward kinematics incorporating loss due to dehydration. Simulation has been performed for two segmented IPMC patches to demonstrate the change in bending resistance, bending response, and end-tip positioning for various input voltages.

An optimized frequency-dependent multiphysics model for an ionic polymer–metal composite actuator with ethylene glycol as the solvent

IPMCs are electroactive polymers which can be used both as sensors and as actuators. The modeling of IPMC transducers is an open issue relevant to the development of effective applications. A multiphysics model of IPMC actuators is here implemented. It integrates the description of the electrical, mechanical, chemical and thermal coupled physics domains in a unique solution and, as a novelty, it allows the study in the frequency domain and the comparison with experimental response of the IPMC device. The IPMC white box modeling requires several macro- and microscopic parameters, not always accessible via theoretical approaches or experimentation. This work presents a new model optimization procedure which integrates the Nelder–Mead simplex method with the COMSOL Multiphysics®models. The proposed procedure uses experimental data and fits model simulations to IPMC real behavior for microscopic parameters’ identification. The model is developed for IPMCs with ethylene glycol as the solvent.

Modeling and Control with Hysteresis of Piezoelectric Smart Materials Actuators

Hysteresis hinders the effective use of piezoelectric smart materials in sensors and actuators. This paper proposes a hybrid model that can precisely portray hysteresis in piezoelectric actuators, which is constructed by a preisach operator with a piecewise uniform density function. Then, the corresponding inverse model for hysteresis is developed. It studies online recursive identification of hysteresis drift. Based on the obtained models, a method for simultaneous compensation of the hysteresis of piezoelectric actuator is applied to the control of system nonlinearities. Simulation and experimental results based on an IPMC actuator are provided to illustrate the proposed approach. The result verified the validity of the model and effectiveness of the controller.

Giant Displacements in IPMC-Based Structures: A Preliminary Study

A joint preliminary study has been performed to elucidate the capability of IPMC-based structures mimicking the behavior of biological systems. The structural deformation in response to an applied voltage is described within a nonlinear physics-based model of IPMC actuators. A characteristic of the model is the varying-along-the-thickness relative permittivity of the IPMCs, which takes into account the highly heterogeneous layers resulting from electrode deposition, where charge redistribution occurs. Preliminary experiments on an IPMC-based medusoid are presented to offer some validation of the modeling approach and provide directions for further studies.

A comparison between robust and parameterized controllers for fractional order modeled Ionic Polymeric Metal Composite actuator

In this paper a fractional order transfer function, identified from experimental data, is used to model IPMC actuators. The IPMC model is parameterized as a function of the actuator length. Two different control approaches are proposed and compared; the first one is a parameterized controller designed with a classical frequency domain strategy, while the second is designed by using a robust control approach.

A Scalable Fractional Order Model for IPMC Actuators

AbstractIPMCs are a novel class of composite materials capable of electromechanical reversible transduction. It has been suggested in literature that they can be modeled by using fractional transfer functions. In this paper a gray box approach is used to identify IPMC actuators. Moreover the proposed transfer functions are ruled by using the device geometrical parameters, in such a away to guarantee the control of the transducer behavior during the design phase. Experimental validation of the proposed approach is reported.