The world’s first soft robot goes out of 3D printers to make them

Scientists have achieved what they call the “holy grail” of soft robots: creating flexible four-legged robots that automatically walk directly from the 3D printers that make them.

The palm-sized device is made entirely of soft plastic and powered by compressed air, representing a major breakthrough in manufacturing smart machines without electronic components.

Researchers at the University of Edinburgh have developed an innovative inverted printing technology using its new “Flex Printer” system, a low-cost open source platform that can be assembled for less than £400 using off-the-shelf parts. This achievement marks the first time anyone has successfully printed a robot that is able to walk out of the printing bed immediately after manufacturing.

Revolutionary top and bottom printing

The breakthrough was by printing super virtual material in the inverted direction, which the team found to offer a whole new feature for soft robot manufacturing. Traditional 3D printed flexible materials face fundamental challenges – ultra-soft filaments easily snap and jam when they pass through heated nozzles, resulting in unreliable results.

“It took years to figure out how to print with these materials,” explained Maks Gepner, chief engineer at the University School of Engineering and Informatics. “Using our new platform, anyone can now easily print what was previously thought impossible. It’s a game changer for engineers and artists.”

The inverted method solves multiple technical problems at the same time. Gravity now helps stabilize the vertical structures under tension, rather than making them fasten under compression. This makes film printing crucial for fluid systems, while also allowing longer unsupported spans without sagging, often breaking the flexible printing.

Break the barriers

Soft robotics has great potential in nuclear decommissioning, biomedical equipment and space exploration – a environment where traditional rigid robots struggle. These flexible machines have no spark risk and are not affected by ionizing radiation or high magnetic fields, making them ideal for hazardous conditions.

However, progress is limited by expensive specialized equipment, often costing more than $100,000, extensive technical expertise requirements, and a lack of standardized manufacturing processes. Flex printers address these barriers by democratizing access to technology.

The team’s innovations include several key hardware modifications:

• Wider filament diameter: Using 2.85mm instead of 1.75mm wires to tighten the material seven times, almost eliminating the interference problem
• High-speed printing: Acceleration up to 10,000mm²/s and travel speeds over 500mm/s minimize material leakage without complex retraction settings
• Professional surface: Polyetherimide sheets provide excellent adhesion, eliminating the need for heating beds even when printing inverted
• Optimized cooling: Large fan open design allows for faster and more reliable printing of complex geometric shapes

Entering the future

The demonstrated robot combines embedded fluid logic, which is essentially a pneumatic circuit that controls its movement without any electronic components. The core of the CMOS pneumatic ring oscillator is located in the CMOS pneumatic ring oscillator that generates a three-phase pressure signal, and coordinates the robot’s gait through a “ligament” actuator that moves each limb laterally and a “foot” actuator, thus moving the limbs from the ground.

This achievement is particularly important for the robot’s bill of materials: only one row of flexible TPU filaments is listed. This simplicity provides profound manufacturing advantages, including the resilience of the supply chain, fewer points of failure and the potential to fully recycle recyclability, thus achieving a true circular economy of robotics.

The robot had a pressure of 2.25 and successfully proved to walk off the printing bed while still hanging upside down and then continue walking after repositioning. This capability has been a long-standing milestone in the field.

Open source innovation

Instead of maintaining breakthrough proprietary, the Edinburgh team publicly provides all designs through Github and establishes a collaboration channel through the IEEE Technical Committee’s Soft Robot Technology Committee. They also created the “Brave of Fluid Machines”, an online repository for sharing reusable fluid system components.

“We hope this technology will help drive the next wave of research breakthroughs,” Gepner noted. “Without the long-standing manufacturing and design bottlenecks stopping it, we believe soft robots are ready to have a significant real-life impact.”

The open source approach is designed to promote community-driven innovation rather than competitive confidentiality. First-time users can report assemble systems and start building robots in just a few days, greatly reducing the barriers to expertise that historically limits the field.

Beyond the laboratory

The meaning goes far beyond academic research. Standardized low-cost manufacturing can ultimately transition soft robotics from laboratory curiosity to practical applications. The team envisions robots that are printed and deployed directly at points of use, whether in oil and gas facilities, nuclear cleaning sites, or even in MRI machines where traditional electronics fail.

The researchers acknowledge that their work represents only the beginning of the standardized casting process they hope to be in soft robotics, similar to how standardization achieves the microelectronics revolution. Future developments may include closed-loop printing control, multi-material functions, and further automation of maintenance procedures.

By solving basic manufacturing challenges, the Flex printer platform can shift the focus from figuring out how to make soft robots to exploring innovative applications that benefit society. The technology is expected to change not only robotics research, but also the industry as a whole, gentle, adaptive machine can revolutionize human-machine interactions.