Robotic tail for humans was inspired by seahorses

Robotic tail for humans was inspired by seahorses
Keio University Graduate School of Media Design via CNN
If you're prone to tripping or losing balance, then researchers in Japan may have an unusual solution: a robotic tail.

If you’re prone to tripping or losing balance, then researchers in Japan may have an unusual solution: a robotic tail.

A team at Keio University in Tokyo has designed a wearable human tail, which is attached using a harness and may help the wearer correct their balance the same way animals do.

The “biomimicry-inspired tail” was created after researchers examined mammals and other vertebrates whose tails act as an additional limb. The thick meter-long tail, attached to the wearer’s waist, looks like something out of a sci-fi movie. Covered in vertebrae-like plates, it twitches and twists like a real tail.

Here’s how it works. The tail contains sensors and four artificial “muscles,” which allow it to move in response to the wearer’s movements. For example, if you lean left, the tail swings right. If you lean down, the tail swings upward.

This counter-movement provides enough force to change the body’s momentum and center of gravity, helping to correct balance and give wearers greater stability.

The project, called Arque, is led by Yamen Saraiji, Junichi Nabeshima and Kouta Minamizawa. The researchers came up with the idea last summer. “We were interested in (asking), ‘how can we empower the human body with wearable technologies?'” Saraiji told CNN in a phone interview.

At first, the researchers experimented with prototypes based on cat and tiger tails, though both proved too light to affect the body’s balance. So they switched their focus to seahorse’s tails because they’re larger and heavier, giving the necessary amount of force and momentum.

Saraiji said the tail needs to represent about 5% of the wearer’s body weight in order to be effective, so the prototype’s length and weight can both be adjusted. Because the tail attaches at the waist, wearers “don’t feel any significant weight — until the tail starts moving.”

Saraiji emphasized that the tail is still in the research and development phase, and won’t be available anytime soon. Researchers hope to add more artificial muscles so the tail responds quicker to users’ movements. They are investigating the potential side-effects of long-term use.

Having worked on the tail for the past year, the team unveiled its prototype to the public for the first time two weeks ago, and is already imagining how it might be used.

“We’re interested in collaborating with medical teams to investigate the effectiveness of using this on people with balance disorders,” said Saraiji. “What does the future of human bodies with wearable technology look like in five to 10 years?”

Beyond people with balance and muscle disorders, the tail could also be used to help steady elderly users, or to provide extra support for jobs that require lifting heavy objects, Saraiji said.

It also has potential in the entertainment industry — specifically, in virtual reality and haptic feedback. For instance, if somebody was using a virtual reality product, the tail could help mimic the virtual setting. If the setting showed a strong wind blowing, the tail could unbalance you, making it feel like you’re standing in the wind.

The tail is just the team’s latest product — other researchers from Keio University have also previously experimented with additional wearable limbs, and remotely-operated wearable systems that allow users to “share bodies.”

In recent years, Japan has become a world leader in the booming field of wearable technology.

Tokyo launched a Wearable Expo in 2015, the largest wearable tech fair in the world, featuring everything from electronic gloves for pianists to electronic kimonos.

Some are fun and wacky, like a dog harness that tells owners how their dog is feeling. Others could drastically improve users’ health and quality of life — like robotic exoskeletons that help kids with cerebral palsy walk. Some are smaller and more subtle, but no less useful, like nail stickers with scannable barcodes that could help keep track of senior citizens with dementia.

“Empowering people with disabilities, or people with weak bodies — we hope we can reach this level at some point in the near future,” said Saraiji.