A team of British researchers thinks the future lies in wearable soft robotics. They’ve developed robotic muscles; air filled bubbles of plastic that can raise a leg from a seated to a standing position. Getting this technology into the trousers might be ten years away, but it is set to give that added boost to people’s ability to stand and walk when they need it most.

Professor Johnathan Rossiter, from the University of Bristol, said “there are about 10 million people in the UK with disabilities.” This includes people with functional disability, but also those with mobility problems in old age.

By 2046 the proportion of people over sixty five could grow to nearly a quarter of the population. About 1.2 million people in the UK have had a stroke. Many of these people will need mobility assistance. The problems experienced by people may be in walking, sitting and standing, but also with other day today tasks like dressing. Social services will be under increasing pressure to provide more carers and occupational therapy. This stimulated work by Johnathan Rossiter to use £2m of EPSRC funding to come up with robotic solutions that would improve on the conventional aids of walking stick/frames, wheelchairs, or mobility scooters.

Researchers were showcasing the technology and some of the clothing developed for the first time at this week’s British Science Festival in Hull. Johnathan Rossiter said “One of our goals is to replicate human muscle in an artificial form, so that you can sew them into your trousers and you’ve got your power trousers.”

Johnathan Rossiter has teamed up with scientists from across the UK to bring together nanoparticle science, functional 3D printing, smart material development and artificial muscle technology. He said “Soft robotics can make materials and structures that behave in a really sophisticated way in contrast to conventional robotics. We have evolved organisms that are so sophisticated in their movement in their sensing and in control, like the octopus, they can bend and twist can squeeze into small spaces. We can take some of these capabilities and put them into artificial muscles, put them onto clothing.”

At the science festival, Johnathan Rossiter’s team demonstrated the artificial muscles. They look like strings of cocktail sausages made from clear plastic that feels like carrier bag material and can be inflated with air. Once inflated, the whole structure contracts and shortens like muscle does, and the cocktail sausage shapes becomes round like baubles. There is considerable power generated by the artificial muscle and BBC reporter, Lucy R Green, watched as Johnathan Rossiter demonstrated that this can raise a robotic leg from a seated to a standing position.

Another demonstration showed a cuff of several air filled long plastic sausages arranged around the knee area. Once inflated it became stiffer and more supportive to the knee. Johnathan Rossiter said “It means you can stand more comfortably. You need a cylinder of air in your back pocket and as you walk you get little ‘phutts’ of air as they actuate.”

They are potentially noisy to live with, but the vision the team is developing is one using electroactive polymers, materials that require electricity. Johnathan Rossiter said this was “great, because you’ve got mobile phone batteries, lithium polymer batteries that you can put in your pocket. With those, you have materials that you apply electricity to, and they contract like a muscle.” And of course they would be silent.

Once incorporated into the trousers, there is scope for an embedded control system. The electroactive polymers themselves generate an electrical signal. Johnathan Rossiter said “So we have this ability to measure someone’s movement from the same materials that are also going to deliver the power to the person. The material is do[ing] the sensing, the computation, then they deliver the power to exactly the right place.”

The technology might offer the potential of prolonged independent living, but a potential downside might be discouraging a person from using their own muscles, and then becoming weaker. But Johnathan Rossiter said, as a rehabilitation device, it may be doing the opposite “so that people who are weaker are becoming stronger, working with the device/trousers – they are exercise trousers making their legs stronger, their knees stronger.”

The researchers have also come up with air driven waistbands to trousers which, at a push of a button, will allow trousers to loosen at the waist and drop to the floor. Johnathan Rossiter said “People with functional incontinence just can’t get to the toilet in time and end up using pads. That’s a terrible change in their lifestyle, and we are trying to get around that as well.”

Johnathan Rossiter said “Our target [market] is the kind of person that you or I, if we are relatively healthy, would become as we slowly get older. The health service wants this. It is really good at realising that if you are going to interact with the human body, you probably want something that is soft…rather that one of these scary rigid exoskeletons.”

The next phase of the team’s work is going to involve working with clinicians, charities and prosthetic device companies. Johnathan Rossiter predicts that with the involvement of good design and manufacturing companies, the trousers could be available in ten years. He said “It could be there is a smart knee-brace or a smart ankle brace or a smart pair of pants. So I see low-hanging fruit coming relatively quickly within a few years rather than having to wait for these actual trousers.”

But first, there are quite a few problems for these researchers to crack, such as how to store enough energy in the trousers without it becoming too heavy and storing that energy for long periods of time. As Johnathan Rossiter pointed out “you don’t want to walk up to the top of a hill and then find you can’t get down the other side.”