Princeton Engineers Develop Motorless Soft Robots Utilizing 3D Printed Polymers and Origami Folding Techniques

New research from Princeton University showcases a soft robot that moves using 3D printed polymers and flexible circuits instead of traditional mechanical gears.

By: AXL Media

Published: Apr 9, 2026, 9:29 AM EDT

Source: Information for this report was sourced from EurekAlert!

The Evolution of Motorless Autonomous Movement

Engineers at Princeton University have reached a significant milestone in robotics by designing soft-rigid hybrid machines that operate without the need for internal motors or external pneumatic systems. Published in the journal Advanced Functional Materials, the research details a system where movement is generated entirely through the interaction of electricity and specialized materials. These robots offer a departure from traditional squishy machines that often remain tethered to rigid mechanical parts or bulky power supplies, opening new doors for medical implants and drug delivery systems that must navigate delicate internal environments.

Molecular Engineering and the Art of Folding

The construction of these robots relies on a sophisticated fusion of material science and the ancient art of origami. Lead researchers Emily Davidson and Glaucio Paulino utilized a liquid crystal elastomer, a printable polymer characterized by an ordered molecular structure. By using a customized 3D printer, the team programmed specific molecular alignments within the material. These alignments act as pre-programmed hinges that react to temperature changes, allowing the robot to fold and unfold in precise, predictable sequences derived from mathematical origami patterns.

Integration of Flexible Circuitry and Thermal Control

A critical technical advancement in this project is the seamless integration of flexible printed circuit boards directly into the polymer hinges during the printing process. This method eliminates the need for a separate assembly step and ensures functional consistency across the robot’s frame. These embedded circuits allow for the application of targeted heat to extremely specific zones. When a current is applied, the local heating causes the liquid crystal elastomer to contract, triggering the folding motion without the mechanical friction or wear associated with traditional gears.