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When we hear the word “robot”, we probably think of “the Terminator” from the 1980s movie, or maybe a huge moving arm in a car factory. But a new and expanding field is introducing a new type of robot, with huge potential into our world. We could be seeing these robots being used for a huge assortment of tasks, such as helping surgeons perform operations or testing water quality in the sea.
Soft robotics is a self-explanatory term – it is a subfield of engineering and robotics dealing with robots made from compliant materials, making the robots more animal-like than most robots we see in films and on TV. This area has recently hit the headlines after having huge success making “muscles” which can lift up to 1000 times their own weight. So, is this a one-off success story, or an expanding area to watch?
Robots Have Muscles?
In December last year, researchers from Harvard and MIT published research on robotic muscles they had made which can twist, grab and hold heavy weights. These incredible mechanisms are based on origami and, depending on how they are folded, will deform differently when triggered.
They work by exploiting pressure differences – they are made from an inner folded ‘skeleton’, with a fluid (like air or water) surrounding it, all sealed inside a ‘skin’. To make the robot move, a vacuum is created inside the sealed casing, which causes the skin to collapse onto the skeleton, creating tension and moving the muscle. To help you imagine it, it’s just like putting a spring inside a vacuum packing bag and sucking all the air out – you’d expect the spring to compress as the outside bag presses in on it. This action causes the skeleton to shrink down to just 10% of it’s original size, which means it has a really large range of movement. Another great thing about these robotic ‘muscles’ is the materials they’re made of. They can be made out of relatively thin layers of plastic, meaning they can even be made transparent – speakers which can produce all frequencies of sound which we can hear and are completely transparent have been made using this technology!
A wide variety of robots have been made; some can pick objects up, as well as twisting and moving them. Some can even be attached to people’s skin, controlling their movement. NUI Galway’s Dr Ellen Roche, a biomedical engineer took this idea one step further. Before Dr Roche’s incredible work, people with acute heart failure, whose hearts could no longer pump their blood could be fitted with an LVAD (left ventricular assist device), which literally takes the blood from the very bottom of the heart, sends it through a pump and injects it right into the major artery coming out of the top of the heart.
At first glance, this sounds like a completely reasonable solution. However, as usual, problems lurk just beneath the surface. When blood comes into contact with a foreign surface, the platelets in the blood automatically think they must be outside of the body. Their natural response in this situation, is of course to make the blood clot. This can be absolutely disastrous – if a blood clot travels around in your blood stream, it could block a blood vessel and lead to a stroke or heart attack. To stop this happening, patients with an LVAD need to take blood thinners, which can cause dizziness, weakness and can stop you healing properly from even a small cut. Dr Roche’s idea was to use soft robotics to make a sleeve for the heart, which could pump with it, most importantly never coming in contact with the blood. Dr Roche used the technology I mentioned before to make a silicon sleeve, with fibres capable of contracting and relaxing, to fit around the sleeve.
This process took considerable development – the heart’s motion isn’t a simple squeeze. The heart actually squeezes and twists together at the same time, with different layers of muscle causing these different movements. Dr Roche’s sleeve also has 2 layers, one of which squeezes and one which twists. The sleeve also plugs into the heart’s own electrical network – the tiny electrical signals which tell the heart when to pump, produced by the pacemaker cells, can be tapped into by Dr Roche’s device so the sleeve pumps in time with the heart. Although more testing is needed, this amazing device could change millions of lives and revolutionise the way we look at treating failing organs and other conditions. For example, the same technology is now being used by scientists at Harvard to create exoskeletons to help stroke patients walk again.
In other parts of the world, researchers and engineers are taking inspiration from nature to build their soft robots. At the BioRobotics Institute in Pontedera, Italy, scientists have created robots with movement based on that of octopuses. Octopuses have no bones or hard parts in their bodies, so are an ideal model for a soft robot.
Researchers have created segments which can twist and turn like an octopus’s tentacles. By attaching a camera to this flexible rod, they formed a tool for surgery which allows surgeons to get a close-up view of exactly what they’re doing, from whatever angle they want. If more were needed to convince you that soft robots have buckets of potential for changing the world, they are also seriously cheap to make – with costs for making a robotic arm coming in at under $1, soft robots seem to secure themselves a place in the future of robotics.
If you compared the running of a car factory 50 years ago to today, the impact of traditional “hard” robots (the kind made of metal and nuts and bolts) would be as clear as day. In my opinion, soft robots are on their way to making similar changes to the face of healthcare, manufacture and more in the near future.