Analysis and Engineering of Silicone Actuators as Artificial Muscles for use in Biomimetic Underwater Robots

The use of silicone as an actuator that could serve as an artificial muscle to power underwater vehicles was analyzed. Muscles have attributes that are highly desirable for use in biomimetic underwater robots mimicking fish. They allow a more elegant design, optimized to move in the best way to produce thrust. Current artificial muscles are often inefficient, either in terms of power or in the amount of displacement created. After surveying the existing types of artificial muscles, this research focused on the study of silicone sheets that actuate in the presence of an electric field. An electrode is stenciled on each side of the sheet and an electric potential of four kilo-volts is created between them. The current flow remains low, on the order of about five micro-amps, thus the power draw is also fairly low. This high power efficiency is very important and beneficial when applying the artificial muscle in a biomimetic underwater robot. Different types of silicone, actuating in an electric field, were tested at different thicknesses and pre-strains to find the optimal characteristics in terms of the end displacement produced. The type of silicone had the largest effect on strain, followed by thickness and lastly, pre-strain. This set of optimal parameters will be used in the continuing process of engineering artificial muscle actuators to power biomimetic marine vehicles.