Meeting Abstract
Like all animals, insects depend on the internal movement of fluids to sustain life. Despite their small size, they use complex internal networks to efficiently transport gases, liquids, and food through their bodies. Previously, we studied respiratory patterns found in the Madagascar hissing cockroach (Gromphadorhina portentosa) to understand how abdominal pumping, tracheal compression, and spiracular valving are coordinated to produce airflows. Three key respiratory behaviors were identified: abdominal pumping, tracheal tube collapse, and spiracular valving. We found that the animal is able to control abdominal pumping and spiraclular valving to compensate for changes in oxygen availability, such as increasing the pump frequency when exposed to hypoxic conditions. Here we explore how these behaviors are used to regulate internal flows using a computational fluid dynamics simulation, investigating the following parameters: branching schema, channel width, channel length ratio, pump frequency, pump amplitude, valve phasing, and valve locations. We varied these parameters through a range of values determined from previous animal experiments, as well as purely theoretical states not seen in vivo. Our preliminary results suggest a variety of parameter combinations that can be optimized for flow rate, shear stress on the channel walls, interior mixing, or interior diffusion. In addition to improving our knowledge about how the insect respiratory system coordinates flow production and valving, we aim to apply the results of this study toward developing low-power, small-footprint microfluidic systems for new engineered devices.
