Thrust force characteristics of propulsion mechanism in fluid using variable-bending-stiffness fin modeled on ciliary movement

Abstract

The application of dynamics observed in organisms is very instructive in the field of engineering. We noted the utility of ciliary movement for propulsion in fluid, and developed an enlarged propulsion mechanism modeled on ciliary movement. To realize the effective stroke and recovery stroke of ciliary movement, the mechanism was equipped with a motor on its base and a variable-bending-stiffness fin. The variable-bending-stiffness fin consists of two flexible sheets and electromagnets. Electromagnets control the frictional force between the two flexible sheets. Bending stiffness is controlled dynamically by changing the frictional force between the two flexible sheets. We discussed the thrust force characteristics of the mechanism in water and highly viscous liquid paraffin.