The Tall, the Squat, & the Bendy: Parametric Modeling and Simulation Towards Multi-functional Biohybrid Robots

Abstract

Efficient computational mechanical models are needed to develop complex, multifunctional soft robotics systems. The field of biohybrid robotics is no exception and is currently limited to low degree-of-freedom lab-chained research devices due in part to limitations in existing design tools and limitations in the morphological sophistication of existing biohybrid structures. Here, we present an expanded use of an existing soft body modeling tool PyElastica, along with a parametric design pipeline for generating and simulating a lattice-based distributed actuation biohybrid robot. Our key contribution in this work is the parameterization of the geometry defining the lattice robot architecture both in terms of the bulk structure and the patterning of the muscles on that structure. By encoding multifunctionality in the robot’s architecture, we demonstrate extension, compression, and bending motion primitives exhibited by the same base lattice structure. We achieve structure-wide strains of 49.73% for extension, 30.59% for compression, and a $48.60^{\circ }$ bend angle for the bent configuration, with all simulations completing in less than 45 s. From this pilot study, the computational model will be expanded to capture more complex and functional behaviors, such as esophageal-inspired peristalsis for internal transport, as well as earthworm-inspired locomotion. The computational modeling of these behaviors is a critical step toward the eventual design, fabrication, and deployment of complex biohybrid robots.