IPMC diaphragm

Deformations of circle-shaped IPMC diaphragms were analysed for the circle-shaped and ring-shaped electrode, respectively. Through parametric studies, an electrode shape was chosen for the optimal diaphragm, which generates maximum stroke volume. In order to show the effectiveness of the circle-shaped diaphragm, its stroke volume was compared to 

1 Circle-Shaped Electrode Ring-Shaped Electrode 

Radius of electrode Gray part IPMC (or electrode) and black part Nation (a) (b) 

The total number of elements (Quad4, MSC Software Corp.) [29] used for each model was 400. The symmetry boundary condition was applied to the vertical and horizontal hnes, and fixed boundary condition to the outside edge. As shown in Rgure 9.10, each IPMC diaphragm consists of the IPMC part and a Nation part. Therefore, when a voltage is apphed on an IPMC part, the vertical interface between IPMC and Nation can rotate easily to produce large bending deformation, since Nafion has a low elastic modulus. 

Fringe SC1 DIAPHRAGM. A14 Static Subcase Displacements, Ttanslational (NON-LAYERED) (ZZ) Deform SCI DIAPHRAGM. A14 Static Subcase Displacements, Translational 

A parametric study was conducted to find the optimal electrode shape for a circle-shaped IPMC (radius 10 mm). Fig. 9.14 shows a 1/4 scale FE model of a diaphragm with a circle-shaped electrode. The total number of quad elements was 400 and the synunetry boundary conditions were applied to the vertical and horizontal edges, and the fixed boimdary condition to the 

The normal mode analysis of IPMC diaphragm was performed for the optimal electrode case in order to investigate its dynamic characteristics. For the calculation, the density of Nafion in Li form was 2.078 x 10 kgm. The density of IPMC in Li was assumed to be 2.5 x lO kgm. The computed first (i.e. fundamental) and second natural frequencies were 430 and 1659 Hz, respectively. Given that the driving frequency range of the IPMC diaphragm is less than 40 Hz, the calculated fundamental frequency 

2 Nozzle/diffuser design and flow rate estimation 

More detailed derivation of the flow rate can be found in [Lee and Kim (2006a)]. Fig. 9.20 shows the calculated ratio of the flow resistance coefficients rj, with respect to the diameter Dq, the conical angle a, and the length L of the conical nozzle/diffuser elements. The coeffleient ratio rj decreases as the diameter increases. on the other hand, it increases as the 

The mean output flow rate Q during one period T can be predicted as follows  

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Fig. 9.14 IPMC diaphragm (1/4 FEA model). Reprinted from [Lee and Kim (2006a)]. Table 9.3 Material properties and thicknesses of an IPMC diaphragm.

Plate 4 Normal mode analysis results for an IPMC diaphragm (radius of electrode =8.5 mm) (a) first mode (b) second mode (Reproduced with permission from Lee, S., Kim, K.J. and Park, H.C. (2006) Modeling of an IPMC Actuator-driven Zero-Net-Mass-Flux Pump for Flow Control, J. Intelligent Mat. Systems and Structures, 17, 6, 533-41. Sage Publications). (See Figure 9.14)... 

To predict the behaviour of IPMC diaphragms, the equivalent bimorph beam model, whieh was recently introduced by Lee et al. [28], is adopted in this study. Here, the key ideas of the model are summarized. 

In this chapter, we have described an IPMC-driven infusion micropump for recent biomedical applications. Even though the applieations of IPMCs for biomedical fields require more trials and development methods, IPMCs are still attractive materials due to their electromechanical and mechanoelectric properties. A systematic design method of an IPMC-driven micropump was introduced. In order to properly estimate the deformed shapes of IPMC diaphragms, the equivalent bimorph beam model for IPMC actuators was conveniently used, in conjunction with the finite element method. 

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