High-Velocity, Pressure-Driven Eversion for Rapid Vine Robots
Anna Alvarez, Anders Seawright, Neel Tripathi, Selena Deng, Carlos Cruz, Elliot Wright Hawkes
AI summary
Problem
Prior vine robot research focuses almost exclusively on slow, quasi-static extension, leaving a critical gap in understanding the dynamics, scaling laws, and high-speed applications of rapidly everting soft robots.
Approach
The authors developed a dynamic growth model for high-velocity vine robot extension with payload mass and validated it experimentally across isometrically scaled vine bodies of varying wall thicknesses.
Key results
- First demonstration of a vine robot ballistically launching a projectile
- Record-breaking eversion speed of 60 m/s achieved with a large-scale vine
- Damping increases monotonically with isometric scaling and wall thickness
- Steady-state velocity scales with size while energy efficiency improves with thinner walls
Why it matters
These findings provide a foundational understanding of dynamic soft robot movement, enabling faster designs for medical devices, drug delivery, and projectile launchers while informing biological everting mechanisms.
Abstract
“Vine robots” are thin-walled, tubular, pneumatic soft robots that lengthen at their tips to navigate constrained and complex environments. Previous studies have already explored the mechanics of vine robot bodies and investigated applications for which the device is well-suited. However, these studies almost exclusively focus on eversion rates in the quasi-static regime, overlooking other potential applications of high-speed vine robots in medical devices, projectile launchers, or for informing biology. To better understand this rapid behavior, we present a dynamic growth model for high-velocity vine robot body extension with a payload mass and verify the model experimentally. To the best of the authors’ knowledge, this is the first instance of vine robots utilized for projectile launching. We find three key results: i) vine robot bodies experience rate-dependent damping that is scale-dependent and monotonically increases with increasing wall thickness; ii) steady-state velocity, or the upper limit of speed in terms of growth velocity, monotonically increases with isometric scaling; and iii) energy efficiency increases with decreasing wall thickness. These findings are used to inform the preliminary design of a large-scale, drug delivery device proof-of-concept, as well as design the fastest–on–record vine, capable of 60 m/s eversion. Our work provides a basic understanding of the dynamic movement of vine robots and opens the door to new areas of application.