Aimy Wissa | Searcharxiv

arXiv2026

Cuttlebot: a platform demonstration for complex, autonomous, bio-inspired swimmers

Increasing interest in deep-sea operations and resources motivates the development of ecologically sensitive but environmentally durable robots. Dielectric elastomer actuator artificial muscles are good candidates for powering such systems due to their pressure and temperature tolerance and soft makeup, but they are difficult to integrate with robotic systems. This work presents an autonomous robotic platform: the CORE, capable of driving six artificial muscles while sensing visual and spatial information. To validate the platform, we developed the Cuttlebot - a cuttlefish-inspired robot that swims in three dimensions using undulatory fin locomotion. The Cuttlebot has four primary artificial muscles in its fins in addition to a tentacle-inspired soft gripper. The robot was evaluated in a series of tethered and untethered swimming tests, demonstrating a top speed of 2.5 centimeters per second translation and 10 degrees per second rotation. Furthermore, the CORE system was capable of driving specialized control signals into the artificial muscles to controllably output force and torque in six axes. This work provides a platform for developing complex, bio-inspired swimming robots for ocean exploration and monitoring, laying the foundation with our leading example: the Cuttlebot.

cs.RO↗

arXiv2024

Feather-inspired flow control: The flow physics of spatially distributed covert flaps

This study presents a novel spatially disrupted flow control system inspired by the covert feathers on bird wings. The system is a passive flow control system consisting of multiple feather-inspired flaps that dynamically interact with the surrounding flow to mitigate stall. Incorporating covert-inspired flaps on the suction side of the airfoil resulted in a substantial increase in lift (up to 50%) and a substantial reduction in drag (up to 30%) in post-stall conditions. Using wind tunnel experiments and time-resolved particle image velocimetry, the physical mechanisms responsible for post-stall lift improvements and drag reduction are identified as (1) shear layer interaction and (2) pressure dam effect. In the first mechanism, flap deployment reduces the geometric adverse pressure gradient that the flow encounters, reducing the degree of flow separation. In the second mechanism, the deployed flap acts as a barrier, preventing the relatively high pressure downstream from propagating upstream of the airfoil. The flow control mechanism employed was a function of the location of the flap. Flaps near the leading edge interacted mainly with the shear layer, while flaps near the trailing edge induced a pressure dam effect. Increasing the number of flaps along the chord increased the gain in lift and the reduction in drag. However, additive performance enhancements were sensitive to spatial distribution and flow control mechanisms. The shear layer interaction mechanism is found to be additive; that is, the deployment of additional flaps increases the lift gain, whereas the pressure dam effect is not.

physics.flu-dyn↗