Studies to improve the actuation capability of low-frequency IPMC actuators for underwater robotic applications

Abstract

Underwater robots find application in underwater detection and exploration. IPMC actuator-based underwater robots are advantageous due to its high manoeuvrability and efficiency. This paper addresses the enhancement of actuation parameters such as actuation force and displacement for low-frequency IPMC actuators. To improve the actuation force, the IPMC actuator’s dimensions are analysed. In Part A, the effect of increase in the width and thickness on the actuation parameters is studied by attaching two IPMC along the width (IPMC-W) and along the thickness (IPMC-T). Increase in the length of IPMCs increases the deflection but reduces the actuation force. Therefore, in Part B instead of achieving higher displacement with a single (length = 66 mm) actuator, IPMC actuators (each length = 33 mm) are attached to IPMC-W and IPMC-T actuators of length 33 mm possessing different frequencies. The IPMC that is attached to IPMC-W is referred to as model 1 and the IPMC that is attached to IPMC-T is referred to as model 2. The model 1 shows increased actuation force and frequency values compared to model 2. While the model 2 shows high displacement values at reduced frequency. This study also reveals that the IPMC-W and IPMC-T configurations that operate at low frequency can generate good actuation force without compromising the deflection.