Cable-Free Soft Robotics: How Filaflex 70A Powers 3D-Printed Pneumatic Logic
Cable-Free Robotics: How Filaflex 70A Enabled the Pneumatic Logic of the Future
Bioinspired innovation meets flexible 3D printing
Imagine creating robots that move, grip, and interact with the world—without electronics, cables, or rigid components. That future is now a reality thanks to a groundbreaking project by researchers at the University of Freiburg. Leveraging the unique properties of Filaflex 70A, they’ve developed fully 3D printed pneumatic logic circuits to power the next generation of soft robotics.
Soft robot walker test under extreme load
1. Learning from Nature: Bioinspiration at Its Best
Nature has long inspired engineers and designers in search of efficient and adaptable systems. In this case, the curved posture of human fingers and the tendon-locking mechanism of birds of prey were the key to designing a robotic gripper with natural pre-curved fingers. This bioinspired shape not only improves response time but also allows the robotic actuators to hold objects with minimal energy.
Their design mimics how fingers rest slightly bent, enabling quicker closure—a concept critical for high-speed grasping applications.
2. Material Matters: Why Filaflex 70A Was a Game Changer
The project’s success hinged on finding a flexible filament that could withstand internal air pressure, be printed with precision, and maintain structural integrity in submillimeter wall thicknesses. After evaluating several materials, only Filaflex 70A provided the right balance between elasticity, layer adhesion, and airtightness.
- Enabled airtight membranes of just 0.5 mm thick
- Excellent print speed and surface finish
- Flexible enough to kink tubing without cracking
- Perfect fit for pneumatic systems and soft robotics
Its versatility allowed the team to design logic modules with integrated tubing and chambers—all in a single print job without supports.
3. Pneumatic Logic: Digital Thinking Without Electronics
One of the most revolutionary achievements in this project was the creation of pneumatic logic gates—AND, OR, NOT—entirely printed in flexible material. These gates use differential air pressure to perform Boolean logic functions, enabling full robot control with no electronics.
This leap in pneumatic intelligence made it possible to:
- Control walking gaits in legged soft robots
- Automate peristaltic pumps for liquid transport
- Enable mechanical logic-based user interfaces
- Design ultra-resilient grippers for industrial or care applications
The modular design means these components can be reused and adapted to countless robotics architectures.
4. Interview with Dr. Falk Tauber: Behind the Breakthrough
Dr. Falk Tauber – University of Freiburg
What inspired your actuator design?
“The natural curve of resting human fingers and bird talons. We wanted pre-curved shapes that would snap shut fast, just like in nature.”
How did you choose Filaflex 70A?
“We tested many materials. Filaflex 70A was the only one that gave us speed, layer adhesion, and airtightness—plus it handled 0.5 mm membranes with ease.”
Did you face technical hurdles?
“Yes! Achieving thin, airtight prints was tough. We experimented with extrusion pressure, custom flow settings, and nozzle sizes up to 0.8 mm.”
What’s the most exciting result?
“A fully functioning, electronics-free quadruped robot—printed in one go, using nothing but Filaflex 70A.”
Future directions?
“We're aiming for faster printing, integrated sensing, and medical applications. The flexibility of this logic is immense.”
5. Design Philosophy: Printing for Performance
The entire system was designed around the constraints and strengths of flexible FDM printing. The researchers fine-tuned their CAD models to avoid unsupported overhangs, minimize printhead retractions, and maintain smooth internal airflow paths. All circuits were printed in one session, avoiding support material completely.
This method led to circuits that are not only functional but also visually clean, easily replicable, and scalable. It proves that well-designed soft robotics doesn’t need post-processing or complex assembly—just smart design and the right filament.
6. Applications in Action: Resilience Meets Ingenuity
The team's showcase included two major demos:
- A drink dispenser powered by a pneumatic oscillator and logic gates—no wires involved
- A legged soft robot walker that survived being crushed by a 1,800 kg car, then walked again
These examples prove the viability of flexible, filament-printed robotics for real-world deployment—from factory floors to search-and-rescue zones.
Conclusion
This groundbreaking project combines bioinspired design, pneumatic intelligence, and cutting-edge flexible materials to define a new era of soft robotics. At the core is Filaflex 70A, enabling functionalities that were previously considered impossible for 3D printed systems. From robotics to biomedical applications, this work signals a shift toward smarter, more sustainable, and more accessible robotic technology—entirely powered by flexible matter.
About the Research
📄 Scientific Article:
3D-Printed Digital Pneumatic Logic for the Control of Soft Robotic Actuators
Published in Science Robotics (AAAS)
Date: January 31, 2024
DOI: 10.1126/scirobotics.adh4060
Type: Peer-reviewed research article
🧠 Authors:
S. Conrad, J. Teichmann, F.J. Tauber*, P. Auth, N. Knorr, K. Ulrich, D. Bellin, T. Speck
*Equal contribution (F.J. Tauber & J. Teichmann)
Corresponding Authors:
Dr. Falk J. Tauber
Dr. Stefan Conrad
🏫 Institutions:
University of Freiburg, Germany
- Plant Biomechanics Group @ Botanic Garden
- Cluster of Excellence livMatS
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT)
🧪 Technology & Materials:
- Material: Filaflex 70A (Recreus)
- Fabrication: FDM 3D Printing, no supports
- Systems: Pneumatic logic gates (AND, OR, NOT), drink dispenser, walking soft robot
- Software: PrusaSlic3r 2.4 + modified flow settings
🎤 Interview:
Additional insights were shared in an exclusive interview with Dr. Falk Tauber, providing behind-the-scenes views on the challenges, material selection and vision for future applications in medical and autonomous robotics.
