Riddhi Das

Soft robotic systems have gained widespread attention due to their inherent flexibility, adaptability, and safety, making them well-suited for varied applications. Among bioinspired designs, earthworm locomotion has been extensively studied for its efficient peristaltic motion, enabling movement in confined and unstructured environments. Existing earthworm-inspired robots primarily utilize pneumatic actuation due to its high force-to-weight ratio and ease of implementation. However, these systems often rely on bulky, power-intensive electronic control units, limiting their practicality. In this work, we present an electronics-free, earthworm-inspired pneumatic robot utilizing a modified Pneumatic Logic Gate (PLG) design. By integrating preconfigured PLG units with bellow actuators, we achieved a plug-and-play style modular system capable of peristaltic locomotion without external electronic components. The proposed design reduces system complexity while maintaining efficient actuation. We characterize the bellow actuators under different operating conditions and evaluate the robots locomotion performance. Our findings demonstrate that the modified PLG-based control system effectively generates peristaltic wave propagation, achieving autonomous motion with minimal deviation. This study serves as a proof of concept for the development of electronics-free, peristaltic soft robots. The proposed system has potential for applications in hazardous environments, where untethered, adaptable locomotion is critical. Future work will focus on further optimizing the robot design and exploring untethered operation using onboard compressed air sources.

Seahorses possess a unique tail muscle architecture that enables efficient grasping and anchoring onto objects. This prehensile ability is crucial for their survival, as it allows them to resist currents, cling to mates during reproduction and remain camouflaged to avoid predators. Unlike in any other fish, the muscles of the seahorse tail form long, parallel sheets that can span up to 11 vertebral segments. This study investigates how this distinctive muscle arrangement influences the mechanics of prehension. Through in silico simulations validated by a three-dimensional-printed prototype, we reveal the complementary roles of these elongated muscles alongside shorter, intersegmental muscles. Furthermore, we show that muscles spanning more segments allow greater contractile forces and provide more efficient force-to-torque transmissions. Our findings confirm that the elongated muscle–tendon organization in the seahorse tail provides a functional advantage for grasping, offering insights into the evolutionary adaptations of this unique tail structure.