Pumping potential of a two-layer left-ventricle-like flexible-matrix-composite structure

Abstract

The pumping potential, defined as the amount of relative volume reduction engendered by an applied load (relative input stroke), is an important criterion for flexible-body pumps. It is introduced as a measure of the volumetric efficiency of pumping. The PP of many flexible-matrix-composite (FMC) structures has been considered in the literature. Most recently, the PP of a single-layer left-ventricle-like FMC structure, based on the helical ventricular myocardial band hypothesis, has been investigated. A PP of 1.67–1.9 has been achieved. Though reasonably high, it is much smaller than that of the actual left ventricle of the heart (3.33–4.0). In here this work is extended to a two-layer left-ventricle-like FMC structure, which adopts a more accurate fiber orientation. The PP of the two-layer left-ventricle-like FMC structure is determined experimentally and analytically. A FMC flat band is created then twisted and looped to form the flexible-body structure. The analytical investigation using the ANSYS software engenders a PP of 2.5, and the experimental one using a PU/SMA (shape memory alloy) FMC renders a PP of 2.85. These higher values of PP indicate that accurate fiber-orientation in heart-mimicking flexible-structural pumps is very important.