A Bio-Inspired Robot Using Electro-Conjugate Fluid

Electro-Conjugate Fluid (ECF) is a kind of functional fluid that produces a jet flow (ECF jet) when subjected to high DC voltage. A strong ECF jet is known to be generated in a nonuniform electric field, for example, a field with a pair of needle and ring electrodes. This study introduces the ECF jet in developing a novel bio-inspired robot. We first propose the concept of a robot driven by an ECF jet. The robot is mainly composed of ECF jet generators (a micro fluid pressure source), fiber-reinforced rubber actuators, a built-in spring actuator, and an ECF tank. We next investigate the characteristics of the ECF jet generator, the fiberreinforced rubber actuator, and the built-in spring actuator. As a result, we confirmed that the maximum pressure and flow rate of the ECF jet generator are 32.0 kPa and 27.0 ml/min, respectively, and that the actuators could be driven by the ECF jet. We then developed a bio-inspired robot and demonstrated that the robot could move in a 14 mm diameter acrylic half pipe with 0.6 mm/s, and in a 14 mm diameter acrylic pipe with 0.5 mm/s. The robot is 300 mm long with a mass of 26 g.