All posts by Callum Tyndall

Origami-inspired muscles give soft robots superhero strength

The capabilities of soft robots have increased massively in the last ten years, but have often come with an unfortunate trade-off. While the ability of the robots to mimic natural organisms with their flexibility is impressive, such dexterity involves a reduction of strength in the materials used. However, researchers have now created origami-inspired artificial muscles that allow soft robots to lift objects that are up to 1000 times their own weight.

“We were very surprised by how strong the actuators [aka, “muscles”] were. We expected they’d have a higher maximum functional weight than ordinary soft robots, but we didn’t expect a thousand-fold increase. It’s like giving these robots superpowers,” said Dr Daniela Rus, the Andrew and Erna Viterbi Professor of Electrical Engineering and Computer Science at MIT and one of the senior authors of a paper on the artificial muscles.

“Artificial muscle-like actuators are one of the most important grand challenges in all of engineering,” added Dr Rob Wood, corresponding author of the paper and Founding Core Faculty member of the Wyss Institute. “Now that we have created actuators with properties similar to natural muscle, we can imagine building almost any robot for almost any task.”

Developed by researchers at the Wyss Institute at Harvard University and MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL), the new muscles use just water or air pressure to achieve their results.

They consist of an inner ‘skeleton’ that can be made of various materials, surrounded by air or fluid and sealed inside a plastic or textile bag that serves as the ‘skin’. By applying a vacuum to the inside of the bag, movement is initiated as the skin collapses onto the skeleton and the created tension drives motion.

“One of the key aspects of these muscles is that they’re programmable, in the sense that designing how the skeleton folds defines how the whole structure moves. You essentially get that motion for free, without the need for a control system,” said first author Dr Shuguang Li, a Postdoctoral Fellow at the Wyss Institute and MIT CSAIL.

Images courtesy of Shuguang Li / Wyss Institute at Harvard University

Removing the need for a control system means that the muscles can be both very compact and simple, thus making them more appropriate for use in mobile or body-mounted systems that cannot accommodate large or heavy machinery.

Moreover, they can not only generate about six times more force per unit area than mammalian skeletal muscle, but a single muscle can be constructed within ten minutes from materials costing less than a $1.

By powering the muscles with a vacuum, it allows them to be far safer than most other kinds of artificial muscle being tested as they have a lower risk of rupture, failure, and damage.

The muscles are also highly scalable and can even be built out of the water-soluble polymer PVA, meaning they could be used with minimal environmental impact or even as part of ingestible robots for targeted drug release.

Soft robots may soon be able to do far more than just mimic nature.

Cloning did not cause Dolly the sheep to get arthritis, scientists confirm

A new study has dismissed concerns that cloning caused early-onset osteoarthritis (OA) in Dolly the sheep.

Scientists from the University of Nottingham and the University of Glasgow have published a radiographic assessment of the skeletons of Dolly, Bonnie (Dolly’s naturally conceived daughter) and Megan and Morag (the first two animals to be cloned from differentiated cells) that shows no abnormal OA.

The study follows the team’s research last year into the Nottingham ‘Dollies’, a quartet of sheep cloned in 2007 from the same line as Dolly, that showed the cloned sheep to age the same as naturally born sheep.

According to their assessment of the skeletons, the OA observed within the skeletons is similar to that naturally conceived sheep and Nottingham’s healthy aged clones.

Professor Sandra Corr, Professor of Small Animal Orthopaedic Surgery who has since moved to Glasgow University, said: “We found that the prevalence and distribution of radiographic-OA was similar to that observed in naturally conceived sheep, and our healthy aged cloned sheep.

As a result we conclude that the original concerns that cloning had caused early-onset OA in Dolly were unfounded.”

The new study arose after the findings regarding the Nottingham ‘Dollies’.

Derived from the same cell line that produced Dolly, the four sheep originated from Professor Keith Campbell’s attempts to improve the efficiency of the cloning method somatic-cell nuclear transfer (SCNT) and were left as his legacy to the University of Nottingham.

Studying the ‘Dollies’, Kevin Sinclair, Professor of Developmental Biology, in the School of Biosciences, along with Corr and David Gardner, Professor of Physiology at Nottingham’s School of Veterinary Medicine and Science, found radiographic evidence of only mild or, in one case, moderate OA.

Images courtesy of the University of Nottingham.

Given that the ‘Dollies’ had aged so apparently normal, the team felt that their findings stood in too stark a contrast to reports that cloning had caused Dolly to suffer from early-onset OA. First emerging in 2003, reports stated that at the age of 5½ Dolly was suffering from OA.

However, the only formal record of any OA in Dolly was a brief mention in a conference abstract, stating that Dolly had OA of the left knee.

In the absence of the original records however, the team were compelled to travel to Edinburgh, where the skeletons are stored in the collections of National Museums Scotland.

With special permission from Dr Andrew Kitchener, Principal Curator of Vertebrates at National Museums Scotland, the team then performed the X-rays on Dolly and her contemporary clones to reassess that 2003 diagnosis.

Sinclair said: “Our findings of last year appeared to be at odds with original concerns surrounding the nature and extent of osteoarthritis in Dolly – who was perceived to have aged prematurely. Yet no formal, comprehensive assessment of osteoarthritis in Dolly was ever undertaken. We therefore felt it necessary to set the record straight.”