Spatially-Varying Electric Field Design by Planer Electrodes

Introduction

This chapter describes the design and implementation of fields generation system to drive deformable machine consisting of actively deformable materials. The purpose is developing a system to control the shapes and motions of both simulated and real gel robots using electric fields. Such system has not been investigated before. In chapter 4, the method was proposed which designs materials and fields respectively, considering the local interaction equation that defines the relationship between materials and fields. We focused primarily on the electric fields that drive the material rather than the material itself, since the electric fields are common to all material. It was assumed that there must be an optimal method that brings out the performance of material. In this study, performance was measured by the variety of shapes and motions of machines made from material.

In order to control gel robots, estimates of the set of possible transformations that result from actuation are needed. The model was proposed which describes the deformation process of the gel in chapter 2, and identified model parameters in chapter 3. The model supposes that the state of the gel is calculated from the local interactions between the gel and the molecules driven by the electric field. Since the chemical reaction is located on the surface of the gel, we need to compute the electric field on the surface. Once we obtain an estimate of the electric field on the surface, the state and the shape of the gel can be calculated.

The developed system of this chapter is utilized in the next chapter. The system provides fundamental environment to study motion control of deformable machines, which is studied in chapter 8.

This chapter was adapted from in part, by permission, M. Otake, M. Inaba, and H. Inoue. “Development of Electric Environment to control Mollusk-Shaped Gel Robots made of Electro-Active Polymer PAMPS Gel”, Proceedings of SPIE vol.3987 Electroactive Polymer Actuators and Devices (EAPAD) Y. Bar-Cohen (ed.), pp.321–330, 2000; M. Otake, Y. Kagami, M. Inaba, and H. Inoue, “Dynamics of Gel Robots made of Electro-Active Polymer Gel”, Proceedings of IEEE International Conference on Robotics and Automation, pp.1458–1462, 2001; M. Otake, Y. Kagami, M. Inaba, and H. Inoue, “Motion design of a starfish-shaped gel robot made of electro-active polymer gel”, Robotics and Autonomous Systems, vol. 40, pp. 185–191, 2002.