Biomimetic jellyfish-inspired underwater vehicle actuated by ionic polymer metal composite actuators

Abstract

This paper presents the design, fabrication, and characterization of a biomimetic jellyfish robot that uses ionic polymer metal composites (IPMCs) as flexible actuators for propulsion. The shape and swimming style of this underwater vehicle are based on the Aequorea victoria jellyfish, which has an average swimming speed of 20 mm s −1 and which is known for its high swimming efficiency. The Aequorea victoria is chosen as a model system because both its bell morphology and kinematic properties match the mechanical properties of IPMC actuators. This medusa is characterized by its low swimming frequency, small bell deformation during the contraction phase, and high Froude efficiency. The critical components of the robot include the flexible bell that provides the overall shape and dimensions of the jellyfish, a central hub and a stage used to provide electrical connections and mechanical support to the actuators, eight distinct spars meant to keep the upper part of the bell stationary, and flexible IPMC actuators that extend radially from the central stage. The bell is fabricated from a commercially available heat-shrinkable polymer film to provide increased shape-holding ability and reduced weight. The IPMC actuators constructed for this study demonstrated peak-to-peak strains of ∼0.7% in water across a frequency range of 0.1-1.0 Hz. By tailoring the applied voltage waveform and the flexibility of the bell, the completed robotic jellyfish with four actuators swam at an average speed 0.77 mm s −1 and consumed 0.7 W. When eight actuators were used the average speed increased to 1.5 mm s −1 with a power consumption of 1.14 W.

Fundamentals of soft robot locomotion

“…The robot was made of an umbrella-like silicone body actuated by SMAs to enforce the inflation/ejection routine. This pioneering robot was followed by several alternative implementations employing a multi-wall carbon nanotube as a power supply [120], ionic polymer metal composites as actuators [121], iris mechanisms actuated by DC motors [122] and a dielectric elastomer actuator [123] as a shape-changing mechanism.…”

Jellyfish fisheries in the Americas: origin, state of the art, and perspectives on new fishing grounds

“…Research on some groups of jellyfish has led to a better understanding of ocular evolution (Nilsson et al 2005), as well as two Nobel Prizes: one in 1913 for the discovery of anaphylaxis, and another in 2008 for the discovery and development of green fluorescent protein (GFP). Jellyfish have also informed the field of design engineering (e.g., Dabiri 2011; Najem et al 2012;Ristroph and Childress 2014), where their biomechanics are often mimicked due to their simple and efficient design (Gemmell et al 2013). Most of the above applications do not require the removal of jellyfish from the wild at commercial scales.…”

Bioinspired travelling wave generation in soft-robotics using ionic polymer-metal composites

“…A mantaray inspired soft robot was designed by Chen et al using IPMCs to swim throughout water similarly to that of the animal it mimics (Chen et al 2012). Jellyfish have inspired many researchers to use IPMCs for various biomimetic applications (Yeom and Oh 2009;Guo et al 2007; Akle et al 2011;Najem et al 2012). Aureli et al designed a fish-like robot that uses an IPMC for the tail (Aureli et al 2010), while Aftab et al create a three linkage system using an IPMC to actuate the fin on their fish-like robot (Ul Haq et al 2015).…”

“…Herein, the authors present a method of design and study of generating the flying-fish-like travelling wave motion using soft-robotic actuators, specifically ionic polymer-metal composites (IPMCs), which were selected due to their aptitude for operating in an aqueous environment, large bending displacement, and low power requirements. Additionally, IPMC have been used successfully in underwater biomimetic actuators and vehicles (Chen et al , 2012Kim et al 2011;Palmre et al 2013;Yeom and Oh 2009;Guo et al 2007;Akle et al 2011;Najem et al 2012;Aureli et al 2010). The results are presented along with discussion and a plan for future work.…”