جستجوی مقالات مرتبط با کلیدواژه « ionic-polymer-metal composite » در نشریات گروه « مکانیک »

Ionic Polymer-Metal composite (IPMC) actuators are very thin sandwich strips with an electroactive polymer in the middle and two metal electrodes on the sides. The coupling of electric, chemical and mechanical fields causes bending deformation, as applying voltage to the electrodes leads to the ions migration through the thickness. In this paper, a nonlinear coupled electrochemical mechanical analysis of the actuation response of an IPMC cantilever is performed. First, the primary electrochemical response is obtained by coupling chemical and electric fields. This equation is solved by the finite difference method using the Newton-Raphson method. This response inserts into the mechanical field. Using the solvent transfer equation, the eigen strain and bending moment rates are obtained. By extracting the water coverage in the boundary layer of cathode and anode, the cantilever end displacement is determined. The results are compared and validated with the finite element simulation done in the current work and previous available studies. The results show reasonably a fit between the response of the actuator and the electrical excitation, and confirm the presented model provides the fast response prediction of the strip. Under 1 Volt excitation, the maximum and residual deflections of the cantilever end were found to be 0.11 and 0.04 of the strip length, respectively, and the cation concentration in the middle of the thickness was calculated to be 1150 mol/m3.

Ionic Polymer-Metal Composite (IPMC) strips are very thin actuators in the form of a sandwich composite with an electroactive polymer in the core and two metal electrodes on its sides. In this paper, a multi-scale electrochemical-mechanical analysis of actuation time response of an IPMC composite strip is performed. First, the electrochemical response of IPMC primary motion stemming from electrostatic force, viscous force of ionic cluster motion in the polymer matrix solvent, and diffusive force caused by the concentration potential are obtained by a hydraulic model. The solution methods in the space domain include finite element numerical analysis based on Glerkin's formulation, and Euler's integration method in the time domain. Then, the solvent transport equation is written, and the rate of eigen strain and bending moment of the IPMC actuator is obtained. By extracting the amount of cluster concentration in the boundary layer of cathode and anode, the displacement response of the end of the beam is determined. The results of the model are validated with previous available studies. The results show a reasonable fit between the response of the IPMC actuator and the electrical excitation, and confirm that the presented model provides the prediction of the fast response of IPMC strip.

Electromechanical material under applied voltage will be deformed; nowadays these materials have diverse abilities which caused enormous attention and interest on them. In this research, a membrane from ionic – polymer - metal composites are manufactured; its strain is significant. Its main core is based on an electroactive core named Nafion® and the electrodes are made of metals such as Platinum which is a noble metal. Then 3 different voltages applied to the ionic – polymer - metal composites which were 2, 3.3 and 5 volts in step form; it should be mentioned that this is the last safe amount of voltage after measuring the deformation combining it with voltage and analyzing it with finite element method; however, It is a theoretical method. the young module or in the other word elasticity modulus, is measured which is 0.57×109 Pa and is a precise amount which can be used in the future research.

Ionic polymer metal composites, IPMCs, are a novel class of electro-active polymers (EAPs) which bends in response to a relatively low electrical voltage due to the motion of cations in the polymer membrane. IPMC materials have wide range of applications in robotics, biomedical devices and artificial muscles. This paper presents a fuzzy logic approach to electromyogram (EMG) pattern recognition for an IPMC actuating system with EMG signal. EMG signals generated by the contraction of muscles in the human forearm were used as an electrical stimulus for actuating the IPMC actuator. EMG is a method of recording and quantifying the electrical activity produced by muscle fibers of motion units. Fuzzy inference system can be used to map an input feature onto an output class. Fuzzy data clustering was used to categorize the muscle signals and recognize the contraction of the muscle. Also we need to consider the mechanical design matters such as light weight and small size with flexible behavior. The IPMC in particular has been vastly applied to the artificial muscle because it is driven by a relatively low input voltage. This EMG signal generated from the human flexor Carpi ulnaris muscle was pre-amplified before transferring to IPMC for achieving the large bending behavior of this actuator. The experimental results, confirm ability of IPMC as artificial muscle which actuating with EMG signals.

For developing of endoscopic Capsular, a design of legged capsular microrobot with ionic polymer metal composite actuator is suggested in this paper. First locomotion of microrobot is explained then microrobot is modeled by envisage exerting surface forces and microactuator. Surface forces contain slip-friction, surface adhesion and resting adhesion and polymeric microactuator is ionic polymer metal composite. Time variant response of polymeric microactuator is modeled fundamental of coupled electromechanical equation and electric equivalent bulk gel polymeric.
Result simulation of dynamical model microrobot shows that best installation angle of legs is 60 degree, proper mass of microrobot is 2g and speed marching is 1 millimeter per second.