3D Printable Crease-Free Origami Vacuum Bending Actuators for Soft Robots
Zhanwei Wang, Chen Huaijin, Syeda Shadab Zehra Zaidi, Ellen Roels, Hendrik Cools, Bram Vanderborght, Seppe Terryn
AI summary
Problem
Vacuum-driven bending actuators suffer from limited bending angles and force due to constrained negative pressure, while traditional origami-based designs require premade creases that complicate manufacturing and reduce durability in soft elastomers.
Approach
The authors engineer a stiffness-distribution-based structure that mimics origami folding without physical creases, allowing the actuator to self-fold under vacuum and be printed as a single airtight piece from soft thermoplastic polyurethane.
Key results
- Achieves up to 138° bending angle in a compact form
- Enables single-material, airtight 3D printing of soft actuators using modified consumer FFF printers
- Demonstrates modular reconfiguration for adaptable soft locomotion
- Integrates with self-closing suction cups to form a versatile octopus-like vacuum gripper
Why it matters
Simplifies the fabrication and deployment of durable, high-performance vacuum actuators for adaptive soft robotics and versatile object manipulation.
Abstract
While vacuum-based bending actuation offers bene- fits such as safety and compactness in soft robotics, it is often over- looked due to its limited actuation pressure, which restricts both bending angle and force output. This study presents a crease-free, origami-inspired vacuum bending actuator that advances both state-of-the-art vacuum bending actuators and traditional origami deformation principles by introducing orderly self folding through optimized stiffness distribution. Achieved through finite element method, this design provides several advantages: 1) Self-folding allows for high bending angles (up to 138◦) in a compact form. 2) The crease-free design facilitates 3-D printing from a single soft material using a consumer-level fused filament fabrication printer, specifically thermoplastic polyurethane with a Shore hardness of 60 A, potentially higher flexibility and durability. 3) The compact configuration enables modular design, supporting reconfiguration as demonstrated in adaptable locomotion soft robots. 4) The large bending angles allow the actuator to wrap around objects, offer- ing extensive contact compared to other designs. This capability, combined with its vacuum-driven mechanism, enables synergy with self-closing suction cups in an octopus-like vacuum gripper, providing large versatility and grasping force for handling a wide range of objects, from small, irregular shapes to larger, flat items.