Prediction of the Actuation Property of Cu Ionic Polymer–Metal Composites Based on Backpropagation Neural Networks

Abstract

Ionic polymer–metal composite (IPMC) actuators are one of the most prominent electroactive polymers with expected widespread use in the future. The IPMC bends in response to a small applied electric field as a result of the mobility of cations in the polymer network. This paper proposes a Levenberg–Marquardt algorithm backpropagation neural network (LMA–BPNN) prediction model applicable for Cu/Nafion-based ionic polymer–metal composites to predict the actuation property. The proposed approach takes the dimension ratio (DR) and stimulation voltage as the input layer, displacement and blocking force as the output layer, and trains the LMA–BPNN with the experimental data so as to obtain a mapping relationship between the input and the output and obtain the predicted values of displacement and blocking force. An IPMC actuating system is set up to generate a collection of the IPMC actuating data. Based on the input/output training data, the most suitable structure was found out for the BPNN model to represent the IPMC actuation behavior. After training and verification, a 2-9-3-1 BPNN structure for displacement and a 2-9-4-1 BPNN structure for blocking force indicate that the structure can provide a good reference value for the IPMC. The results showed that the BPNN model based on the LMA could predict the displacement and blocking force of the IPMC. Therefore, this model can become an effective solution for IPMC control applications.

Fabrication and Actuation of Cu-Ionic Polymer Metal Composite

“…Figure 7 shows the tip forces of the IPMCs with various lengths under different voltages. As shown in previous studies [28,29], in general, the tip fore of all samples reached its peak value over a certain time period and then fastly decreased. The L1 and L4 continuously increased to the maximum tip forces of 15 mN and 8.8 mN at 8 V, respectively.…”

“…We used Nafion-117 as the substrate membrane. The specific processes are as follows [24,26,28,29]. Pre-treatment: in order to increase the interfacial area and enhance adhesion between the Nafion membrane and electrodes, the surface of the Nafion was roughened using sandpaper, and ultrasonically cleaned in deionized (DI) water (40 min, 60 • C) then successively immersed in 2 mol/L hydrochloric acid (20 min, 60 • C) and DI water (30 min, 60 • C) to purify the ionomer membrane.…”

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

“…The model function proposed in this article can accurately evaluate the displacement and force of the IPMC and reflect the characteristic points well and obtain data other than experimental data. Although the mathematical models [9,12,15] of IPMC can also be predicted by fitting the experimental data, these models often lack the theoretical basis of physics and do not take into account the movement mechanism and driving characteristics of IPMC. Therefore, it is necessary to establish the actuation models of IPMC based on the micromechanics of cation motion.…”

“…A back‐propagation neural network prediction model was proposed for IPMC to predict the actuation property. [ 9 ] The electrochemical characteristics of IPMCs were investigated and a circuit model reflecting their nonlinearity was established. [ 10 ] The actuation models of IPMC were established by calculating the Young's modulus of bare Nafion membrane in different ionic forms and water‐saturated states and modifying the bare‐polymer stiffness model.…”

Surface roughening of Nafion membranes using different route planning for IPMCs

“…Since the introduction of smart materials in the 1980s, to the present fourth generation of materials, smart materials have gradually become the development object of key cutting-edge new materials technology [1]. Ionic polymermetal composite (IPMC), as one of the new smart polymer materials, with the characteristics of low voltage and large deformation, has been widely concerned [2,3], and have been applied in artificial muscles, bionic robots, aerospace equipment, bioengineering, flexible mechanical brakes, medical instruments, and other fields [4][5][6]. It is composed of electrode material on both sides and basement membrane wrapped in the middle.…”