Biologically Inspired Fluidic Flexible Matrix Composite Pumps for Wave Energy Conversion

Inspired by the fibrillar network in plant cell walls and the helical fibers found in soft bodied hydrostats (e.g. worms, squid, elephant trunks, and octopus arms), fluidic flexible matrix composites (F2MCs) are composite tubes that consist of multiple layers of oriented, high performance fibers, such as carbon, precisely placed in a flexible matrix resin to form high-mechanical advantage actuators and variable stiffness materials. Unique to the F2MC tube is its ability to generate high pressures and volume change with a small external load as a result of the stiff reinforcement fiber orientation in the wall of the tube and the soft supporting elastomer. When a load is applied to the tubes, the volume of the composite pump is reduced and fluid is forced out of the tube by the reinforcing fibers. The objective of this research is to design, fabricate and characterize F2MCs for use in wave energy conversion where ocean waves provide the axial load to drive fluid through the pumps. F2MCs pumps are tested in a water basin and mechanically cycled between 0 Hz and 2 Hz at up to 17 percent strain. Instantaneous input power is found by measuring the displacement and applied force to the actuators, while output power values are derived from pressure and flow rate measurements at the tube outlet. From these measurements the actuator efficiency is subsequently determined.