In the rapidly evolving field of robotics, the seamless integration of soft materials and advanced engineering has opened new horizons for creating machines that mimic the fluidity and adaptability of biological organisms. Researchers at Princeton University have made a significant breakthrough by developing a hybrid soft-rigid robot that can move and reshape itself without relying on traditional motors or external pneumatic systems. Their innovative approach combines a unique 3D-printed polymer with flexible electronics and strategic folding techniques inspired by origami — the ancient Japanese art of paper folding — thereby enabling precise, programmable movements through controlled heating.
Soft robotics have long held promise for transforming medical devices, drug delivery systems, and exploration technologies due to their gentle interaction with delicate objects and dynamic environments. However, existing systems often struggle with integrating the softness of materials with the mechanical strength or power requirements needed for complex movement. The Princeton team’s solution addresses this challenge by merging a liquid crystal elastomer (LCE), a polymer known for its molecularly ordered yet flexible properties, with embedded printed circuit boards (PCBs) designed to heat specific regions of the structure and induce movement via thermal contraction.
At the heart of this innovation lies a custom 3D printing technique developed by Professor Emily Davidson’s laboratory. This method deposits molten LCE into meticulously patterned zones in which the molecular orientation is deliberately controlled. By programming distinct alignments within the polymer, these zones act as hinges that fold or bend in a predetermined manner when subjected to heat. These hinges become the mechanical joints that enable the robot to transform shapes and perform repeated motions without incurring material fatigue or deformation, a remarkable advancement in the durability of soft robotic systems.
The research took a hands-on shape with a remarkable demonstration of a soft robot modeled after a traditional origami crane. The robot flaps its wings when electricity passes through the embedded flexible PCBs, which locally increase the temperature of the liquid crystal elastomer hinges. The heating triggers contraction along specific molecular alignments, causing the origami-inspired folds to activate and produce smooth wing movements. This elegant system bypasses the necessity for bulky motors or external tubing, significantly reducing the robot’s weight and complexity.
Integration of the flexible electronics within the polymer was a critical step toward fabricating a fully functional soft robot. The PCBs are not simply attached onto the surface but embedded directly into the 3D-printed structure. This co-fabrication allows for precise alignment between the polymer’s hinge zones and the circuit components responsible for heating and sensing. Embedded temperature sensors afford a closed-loop control system capable of adjusting the thermal actuation in real-time, enabling the robot to correct for minor inaccuracies and maintain its programmed motion sequences reliably over repeated cycles.
The engineering advancement also extends to the mathematical modeling of motion, relying heavily on origami principles. Professor Glaucio Paulino’s team has pioneered the application of origami mathematics to robotic design, leveraging complex folding patterns to create reconfigurable systems that are not only mechanically efficient but also programmable with digital control. These origami-inspired robots can adapt to different conditions, perform navigation tasks, and potentially execute complex functions within constrained spaces where traditional robots cannot operate.
The project began as an undergraduate thesis by David Bershadsky at Princeton, who aimed to create robotic unit cells capable of volume-based transformations. Mentored by Davidson and influenced by Paulino’s origami engineering course, Bershadsky contributed to integrating varied fields such as materials science, electrical engineering, and robotics design. This cross-disciplinary hybrid approach was key to overcoming the challenges posed by combining distinct technologies into a single cohesive system.
One of the standout contributions of this work lies in the manufacturability of the soft robotic system. By employing commercially feasible printed circuit boards and advanced 3D printing techniques, the team demonstrated a path toward scalable fabrication. The synchronization between the polymer hinge properties and PCB actuation capabilities presents a new paradigm for producing soft robots that can be customized and programmed digitally, paving the way for practical applications ranging from implantable biomedical devices to exploratory machines in hazardous environments.
The science behind the actuation mechanism depends on the anisotropic contraction properties of the liquid crystal elastomer when heated. The orientational order of the LCE molecules means that when heat is applied, sections aligned in a particular direction contract sharply while adjacent areas remain relatively stable. This differential contraction creates controlled bending at the hinge interfaces, turning simple heating inputs into complex three-dimensional movements — an approach that distinctively avoids mechanical wear associated with conventional motors and servos.
In addition to mechanical resilience, the robot’s ability to receive sensory feedback enhances its precision and long-term performance. Embedded thermal sensors monitor the temperature at hinge points, and embedded software algorithms dynamically adjust the heating pattern to compensate for any deviations caused by repeated folding or environmental conditions. This closed-loop system ensures consistent motion patterns crucial for applications requiring exact and repeatable behavior, such as minimally invasive medical procedures or precision agriculture.
The success of this project is also attributed to the collaborative culture fostered at Princeton University, combining expertise from material scientists, electrical engineers, and mechanical engineers working in harmony. The integration of flexible printed electronics with soft materials demonstrates the potential of such interdisciplinary teams to push the boundaries of what is possible in micro-robotics and actuated soft devices, inspiring further research into longevity, adaptability, and functional complexity.
Beyond the initial demonstration, the research provides a foundation for further innovations in programmable material systems, where embedded intelligence and actuation can be designed into the material itself. By sharing the software tools on an open-source platform, the team encourages other researchers to develop bespoke robots tailored for specific tasks, accelerating progress in fields where soft robotic technologies are poised to have transformative impacts.
This study signifies a leap forward in robotic design, illustrating how ancient principles of origami, modern polymer science, and cutting-edge electronics can converge to produce elegant, efficient machines. As soft robotics continues to expand into diverse applications — from surgical instruments that minimize tissue damage to adaptive environmental sensors — advances like this will be instrumental in realizing the full potential of biomimetic, motor-free robotic actuation.
Subject of Research: Not applicable
Article Title: Digital Actuation Control of Soft Robotic Origami With Self-Folding Liquid Crystal Elastomer Hinges
News Publication Date: 20-Mar-2026
Web References:
Advanced Functional Materials Journal Article
References:
Bershadsky, Davidson, Paulino, and Zhao. Digital Actuation Control of Soft Robotic Origami With Self-Folding Liquid Crystal Elastomer Hinges. Advanced Functional Materials, March 20, 2026.
Image Credits:
Princeton University
Keywords
Robotics, Robot control, Robot kinematics, Robotic designs, Soft robotics, Polymer engineering, Synthetic polymers, Applied mathematics
