Bio-Inspired Rolling-Disk Continuum Robot: Logarithmic Spiral and Constant Curvature Design with Contraction Capabilities
Md Modassir Firdaus, Vikranth Mallru, Harsh Malodia, Madhu Vadali
AI summary
Problem
Existing bio-inspired soft robots struggle with fixed lengths, complex elastic interconnects, and absent central lumens, limiting their dexterity, scalability, and medical applicability.
Approach
The authors propose a rolling-disk-based kinematic architecture that uses a chain of tangent circular disks to mathematically derive and physically fabricate a 3D-printable continuum backbone capable of logarithmic spiral and constant-curvature bending with active contraction.
Key results
- 3D-printable design enables logarithmic spiral and constant-curvature bending
- Integrated central hollow passage supports minimally invasive tool mounting
- Active contraction capability allows dynamic length adjustment
- Simulations and experiments confirm low tip deviation (<2 mm) and successful grasping
Why it matters
This scalable, tendon-driven design bridges biological inspiration and practical engineering, advancing soft robotics for medical procedures and versatile manipulation tasks.
Abstract
Soft robotics draws inspiration from biological appendages like seahorse tails, octopus arms, and elephant trunks, which demonstrate remarkable flexibility and diverse functionalities. While advances in soft robotics have enabled delicate manipulation, safe human interaction, and medical applications, existing systems lag behind mimicking nature with a change in length. This paper presents a novel rolling-disk- based continuum robot design that replicates natural logarith- mic spiral geometry while overcoming limitations of previous bio-inspired systems, including fixed length, complex elastic interconnects, and absent central lumens. The proposed 3D- printable architecture enables cost-effective rapid prototyping with adjustable parameters, achieving both logarithmic spiral and constant curvature bending, consistent with established kinematic models. A central hollow passage supports tool integration for minimally invasive procedures, while contraction capability enables dynamic length adjustment. Comprehensive mathematical analysis, CAD development, and SOFA sim- ulations validate the design conceptualisation. Experimental demonstrations confirm bending, contraction, and grasping capabilities across diverse object geometries, establishing a foun- dation for scalable, adaptable tendon-driven continuum robots that bridge biological inspiration with practical engineering implementation.