Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Snake-inspired robot uses kirigami to move


Bioinspired soft actuator crawls without rigid parts

Who needs legs? With their sleek bodies, snakes can slither up to 14 miles-per-hour, squeeze into tight space, scale trees and swim. How do they do it? It's all in the scales. As a snake moves, its scales grip the ground and propel the body forward - similar to how crampons help hikers establish footholds in slippery ice. This so-called friction-assisted locomotion is possible because of the shape and positioning of snake scales.

Video: Harvard researchers have developed a soft robot inspired by snakes. The robot is made using kirigami -- an ancient Japanese paper craft that relies on cuts, rather than origami folds, to change the properties of a material. As the robot stretches, the flat kirigami surface is transformed into a 3D-textured surface, which grips the ground just like snakeskin.

Credit: Harvard SEAS

Now, a team of researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) has developed a soft robot that uses those same principles of locomotion to crawl without any rigid components.

The soft robotic scales are made using kirigami - an ancient Japanese paper craft that relies on cuts, rather than origami folds, to change the properties of a material. As the robot stretches, the flat kirigami surface is transformed into a 3D-textured surface, which grips the ground just like snakeskin.

The research is published in Science Robotics.

"There has been a lot of research in recent years into how to fabricate these kinds of morphable, stretchable structures," said Ahmad Rafsanjani, a postdoctoral fellow at SEAS and first author of the paper. "We have shown that kirigami principles can be integrated into soft robots to achieve locomotion in a way that is simpler, faster and cheaper than most previous techniques."

The researchers started with a simple, flat plastic sheet. Using a laser cutter, they embedded an array of centimeter-scale cuts, experimenting with different shapes and sizes. Once cut, the researchers wrapped the sheet around a tube-like elastomer actuator, which expands and contracts with air like a balloon.

When the actuator expands, the kirigami cuts pop-out, forming a rough surface that grips the ground. When the actuator deflates, the cuts fold flat, propelling the crawler forward.

The researchers built a fully untethered robot, with its integrated onboard control, sensing, actuation and power supply packed into a tiny tail. They tested it crawling throughout Harvard's campus.

The team experimented with various-shaped cuts, including triangular, circular and trapezoidal. They found that trapezoidal cuts - which most closely resemble the shape of snake scales -gave the robot a longer stride.

"We show that the locomotive properties of these kirigami-skins can be harnessed by properly balancing the cut geometry and the actuation protocol," said Rafsanjani. "Moving forward, these components can be further optimized to improve the response of the system."

"We believe that our kirigami-based strategy opens avenues for the design of a new class of soft crawlers," said Katia Bertoldi, the William and Ami Kuan Danoff Professor of Applied Mechanics and senior author of the paper. "These all-terrain soft robots could one day travel across difficult environments for exploration, inspection, monitoring and search and rescue missions or perform complex, laparoscopic medical procedures."


Bertoldi is also an Associate Faculty of the Wyss Institute for Biologically Inspired Engineering at Harvard University.

This research was co-authored by Yuerou Zhang, Bangyuan Liu and Shmuel M. Rubinstein, Associate Professor of Applied Physics at SEAS. It was supported by the National Science Foundation.

Media Contact

Leah Burrows


Leah Burrows | EurekAlert!

More articles from Information Technology:

nachricht Next Generation Cryptography
20.03.2018 | Fraunhofer-Institut für Sichere Informationstechnologie SIT

nachricht TIB’s Visual Analytics Research Group to develop methods for person detection and visualisation
19.03.2018 | Technische Informationsbibliothek (TIB)

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>