Tag Archives: morphing robots

Paracrystalline carbon nanoparticles and morphing soft robots

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Michael Berger’s June 19, 2025 Nanowerk spotlight article focuses on a new development where soft robots are concerned, Note: A link has been removed,

The flexibility of living tissue inspires efforts to build robots that are soft, adaptive, and capable of complex movements. Creating such machines is technically demanding, especially when they must operate without physical tethers. Soft robots need materials that deform easily, actuators that respond quickly, and control methods that are both precise and lightweight. Most existing approaches fail to deliver on all three. Magnetic systems require bulky hardware. Light and heat actuation offer wireless control, but struggle with speed and complexity. Electric fields offer a promising alternative—but only if the materials can translate field stimuli into fast, large-scale movement without relying on wires or embedded circuitry.

Traditional electrically responsive gels deform slowly, limited by the movement of ions. Other systems, such as dielectric elastomer actuators, produce stronger and faster responses but rely on internal electrodes or onboard electronics that compromise their softness and range of motion. To make electric-field actuation practical for untethered soft robots, materials must respond quickly, deform extensively, and be controlled entirely from the outside. Advances in soft polymers and conductive nanomaterials have opened the door to this possibility.

A study published in Advanced Materials (“Electric Field Driven Soft Morphing Matter”) reports a material system that meets these criteria. Developed by researchers at the University of Bristol and Imperial College London, the material—called electro-morphing gel, or e-MG—combines a soft elastomer, a dielectric liquid, and paracrystalline carbon nanoparticles. When exposed to externally applied electric fields, e-MG exhibits fast, large, and reversible shape changes. These include stretching, twisting, bending, and locomotion. All movements are controlled wirelessly through low-cost external electrodes.

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Demonstration of the deformability of e-MG robots. a) Illustration of the e-MG material structure and its principle of actuation under an electric field. b) Conceptual diagram showcasing the potential of e-MG robots in space applications. c) An e-MG gymnast swinging along a ceiling. d) An e-MG snail jumping over a gap. e) An e-MG robot delivering cargo through a channel. Demonstrations in (c–e) were performed in a dielectric liquid environment. Scale bars are 5 mm. Courtesy: Authors and Advanced Materials [downloaded from https://advanced.onlinelibrary.wiley.com/doi/10.1002/adma.202419077]

Berger describes the new material, electro-morphing gel (e-MG), in more detail,

At the heart of e-MG’s performance is its material composition. The elastomer provides structural flexibility, while the dielectric liquid softens the matrix and adjusts its electrical properties. The carbon particles, just tens of nanometers wide, introduce mobile charges. When the concentration of carbon exceeds a critical level—between 0.1 and 0.5 percent by weight—these particles form continuous paths for charge transport. The result is a percolated, electrically responsive gel that deforms rapidly in response to non-uniform electric fields.

The material responds to two physical mechanisms: electrostatic and dielectrophoretic forces. Electrostatic force acts on charges within the gel, pushing it in the direction of the field. Dielectrophoretic force acts on polarized material in a gradient field, pulling it toward stronger regions. When both forces align, the effect is amplified. By varying the carbon content, the researchers could tune which mechanism dominated. Low-carbon samples relied mainly on dielectrophoresis and showed slower actuation. Higher-carbon samples displayed rapid deformation driven by both forces. A carbon loading of 0.5 percent offered the best balance of speed, strength, and fabrication reliability.

The researchers demonstrated a range of complex behaviors enabled by this material. Robots built from e-MG could stretch by nearly three times their length, rotate in place, bend around corners, and spread out across surfaces. In one test, a snail-like robot jumped over a gap using a rapid sequence of stretch and release. In another, a humanoid-shaped robot swung along a ceiling by gripping and releasing electrodes. Because e-MG is soft, the robots can deform to anchor themselves against walls or climb vertical surfaces using only field stimuli.

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To ensure practical utility, the researchers tested the material’s durability and environmental stability. After 10,000 actuation cycles, e-MG continued to perform reliably. Tests in both air and dielectric liquid confirmed consistent behavior across media. The system also remained functional in low-pressure environments designed to mimic space conditions. The use of mineral oil in some tests mimicked reduced gravity and surface friction, showing potential for extraterrestrial applications. The individual components of the material—silicone elastomer, silicone oil, and carbon nanoparticles—are all compatible with known aerospace standards.

The researchers also explored scalability. Miniature versions of the robot, over 4,000 times smaller in volume than their largest counterparts, still displayed the same range of actuation behaviors. This suggests that the material and actuation principles can be applied across different size scales. Potential uses could include navigating narrow spaces, manipulating fragile components, or performing soft contact tasks in confined environments.

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By combining a soft, responsive material with remote electrical control, the e-MG system overcomes key limitations of previous wireless soft robotics. It removes the need for internal circuitry, expands the range of deformation patterns, and enables precise actuation using lightweight external components. Its demonstrated ability to morph, grip, and move through contactless stimulation provides a flexible foundation for new robotic platforms. These could be used in biomedical procedures, industrial inspection, or space exploration—where low weight, high adaptability, and remote control are essential.

Berger’s June 19, 2025 Nanowerk spotlight article has more detail and an embedded video of the soft morphing robots, “This video showcases the versatility of electro-morphing gel (e-MG) robots without internal wiring and controlled by external electric fields. A jelly-like humanoid swings across a ceiling using agile limb movements. A snail-inspired robot jumps across a gap by stretching and contracting its soft body. Another robot navigates a narrow channel, anchoring itself to walls to push a cargo ball forward. These demonstrations highlight the adaptability and wireless control of e-MG systems in diverse tasks.“

Here’s a link to and a citation for the paper,

Electric Field Driven Soft Morphing Matter by Ciqun Xu, Charl F. J. Faul, Majid Taghavi, Jonathan Rossiter. Advanced Materials DOI: https://doi.org/10.1002/adma.202419077 First published: 12 June 2025

This paper is open access.

A robot that morphs from a ground vehicle to an air vehicle using liquid metal

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This video starts slow but the part where the robot morphs is pretty good stuff,

A February 9, 2022 news item on ScienceDaily announces a new approach to shape-changing materials,

Imagine a small autonomous vehicle that could drive over land, stop, and flatten itself into a quadcopter. The rotors start spinning, and the vehicle flies away. Looking at it more closely, what do you think you would see? What mechanisms have caused it to morph from a land vehicle into a flying quadcopter? You might imagine gears and belts, perhaps a series of tiny servo motors that pulled all its pieces into place.

If this mechanism was designed by a team at Virginia Tech led by Michael Bartlett, assistant professor in mechanical engineering, you would see a new approach for shape changing at the material level. These researchers use rubber, metal, and temperature to morph materials and fix them into place with no motors or pulleys. The team’s work has been published in Science Robotics. Co-authors of the paper include graduate students Dohgyu Hwang and Edward J. Barron III and postdoctoral researcher A. B. M. Tahidul Haque.

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A February 9, 2022 Virginia Tech news release (also on EurekAlert) by Alex Parrish, which originated the news item, provides more detail,

Getting into shape

Nature is rich with organisms that change shape to perform different functions. The octopus dramatically reshapes to move, eat, and interact with its environment; humans flex muscles to support loads and hold shape; and plants move to capture sunlight throughout the day. How do you create a material that achieves these functions to enable new types of multifunctional, morphing robots?

“When we started the project, we wanted a material that could do three things: change shape, hold that shape, and then return to the original configuration, and to do this over many cycles,” said Bartlett. “One of the challenges was to create a material that was soft enough to dramatically change shape, yet rigid enough to create adaptable machines that can perform different functions.”

To create a structure that could be morphed, the team turned to kirigami, the Japanese art of making shapes out of paper by cutting. (This  method differs from origami, which uses folding.) By observing the strength of those kirigami patterns in rubbers and composites, the team was able to create a material architecture of a repeating geometric pattern.

Next, they needed a material that would hold shape but allow for that shape to be erased on demand. Here they introduced an endoskeleton made of a low melting point alloy (LMPA) embedded inside a rubber skin. Normally, when a metal is stretched too far, the metal becomes permanently bent, cracked, or stretched into a fixed, unusable shape. However, with this special metal embedded in rubber, the researchers turned this typical failure mechanism into a strength. When stretched, this composite would now hold a desired shape rapidly, perfect for soft morphing materials that can become instantly load bearing.

Finally, the material had to return the structure back to its original shape. Here, the team incorporated soft, tendril-like heaters next to the LMPA mesh. The heaters cause the metal to be converted to a liquid at 60 degrees Celsius (140 degrees Fahrenheit), or 10 percent of the melting temperature of aluminum. The elastomer skin keeps the melted metal contained and in place, and then pulls the material back into the original shape, reversing the stretching, giving the composite what the researchers call “reversible plasticity.” After the metal cools, it again contributes to holding the structure’s shape.

“These composites have a metal endoskeleton embedded into a rubber with soft heaters, where the kirigami-inspired cuts define an array of metal beams. These cuts combined with the unique properties of the materials were really important to morph, fix into shape rapidly, then return to the original shape,” Hwang said.

The researchers found that this kirigami-inspired composite design could create complex shapes, from cylinders to balls to the bumpy shape of the bottom of a pepper. Shape change could also be achieved quickly: After impact with a ball, the shape changed and fixed into place in less than 1/10 of a second. Also, if the material broke, it could be healed multiple times by melting and reforming the metal endoskeleton.

One drone for land and air, one for sea

The applications for this technology are only starting to unfold. By combining this material with onboard power, control, and motors, the team created a functional drone that autonomously morphs from a ground to air vehicle. The team also created a small, deployable submarine, using the morphing and returning of the material to retrieve objects from an aquarium by scraping the belly of the sub along the bottom.

“We’re excited about the opportunities this material presents for multifunctional robots. These composites are strong enough to withstand the forces from motors or propulsion systems, yet can readily shape morph, which allows machines to adapt to their environment,” said Barron.

Looking forward, the researchers envision the morphing composites playing a role in the emerging field of soft robotics to create machines that can perform diverse functions, self-heal after being damaged to increase resilience, and spur different ideas in human-machine interfaces and wearable devices.

Here’s link to and a citation for the paper,

Shape morphing mechanical metamaterials through reversible plasticity by Dohgyu Hwang, Edward J. Barron III, A. B. M. Tahidul Haque and Michael D. Bartlett. Science Robotics • 9 Feb 2022 • Vol 7, Issue 63 • DOI: 10.1126/scirobotics.abg2171

This paper is behind a paywall.