Meeting Abstract

S10-4   10:30 - 11:00  The Pneufish on the Block: Using soft robotic models to investigate the diversity of fish swimming kinematic Wolf, Z*; Lauder, G; Harvard University; Harvard University rzanewolf@gmail.com

Investigating complex physical operations in living organisms, let alone the interaction between organisms and their environments, is often not straightforward or even possible due to obfuscated causal relations, or, sometimes, simply, noncooperative study organisms. Robotic models allow scientists to reduce the complexity of their study systems while maintaining and controlling relevant components. Undulatory locomotion is one such area of investigation where robotic models have helped tremendously. We have developed soft robotic swimming models, the duo- and quad-pneufishes, which utilize pneumatic actuators, or pneunets, as muscle facsimiles. Silicone rubber pneunets consist of a series of connected, segmented chambers that, when pressurized, inflate and press against each other, resulting in a unidirectional curvature. When two pneunets are attached in opposition along a flexible foil ‘backbone’ and inflated in an alternating manner using digital air pressure regulators, the backbone will be pushed from side to side in a flapping motion. Comprised of two and four pneumatic actuators, respectively, the duo-pneufish is a posterior/caudal-fin model while the quad-pneufish, with two sets of muscle analogs, is capable of realistic undulatory patterns. Assembled pneufish were suspended in a recirculating flow tank, and the pneufish were swam across a large range of parameters, focusing on frequency, flow speed, co-activation, air pressures, and active and passive stiffnesses. Results showed strong interactions between stiffness and frequency, while individual parameters have lesser impacts upon performance. The pneufish models are not the only undulatory or soft robotic models of fish locomotion, however, and we will also provide context from the field and compare the pneufishes' performance to other models.