Three graduates from Keio University’s (Japan) graduate school of media design have created a bio-inspire robotic tail — that you can wear.

Arque, the new robotic tail.
Image via Youtube / yamen saraiji.

If you’ve ever envied your pet‘s tail, Junichi Nabeshima, Yamen Saraij, and Kouta Minamizawa have got you covered. The trio designed an “anthropomorphic” robotic tail based on the seahorse’s tail that they chirstened ‘Arque’. The device could help extend body functions or help individuals who need support to maintain balance.

Tail-ored for success

Most animals rely on their tails for mobility and balance. While our bodies lack the same ability, the team hopes that Arque can help provide it. The authors explain in their paper that “the force generated by swinging the tail” can change the position of a person’s center of gravity. “A wearable body tracker mounted on the upper body of the user estimates the center of gravity, and accordingly actuates the tail.”

The tail is constructed out of several individual artificial vertebrae around a set of four pneumatic muscles. The team notes that they looked at the tail of seahorses for inspiration when designing the tail’s structure.

“In this prototype, the tail unit consists of a variant number of joint units to produce,” the trio told The Telegraph. “Each joint consists of four protective plates and one weight-adjustable vertebrae.”

“At each joint, the plates are linked together using elastic cords, while the vertebrae are attached to them using a spring mechanism to mimic the resistance to transverse deformation and compressibility of a seahorse skeleton, and also to support the tangential and shearing forces generated when the tail actuates.”

Arque’s modular design means that its length and weight can be adjusted to accommodate the wearer’s body. Apart from helping patients with impaired mobility, the tail could also be used in other applications, such as helping to support workers when they’re moving heavy loads.

The team also has high hopes for Arque to be used for “full-body haptic feedback”. Just as the tail can be used to change the center of mass and rebalance a user’s posture, it can be employed to generate full body forces (depending on where it’s attached to the body) and throw them off balance — which would help provide more realism to virtual reality interactions.

Arque’s intended use is to be worn, but one has to take into account personal experience and social interactions when predicting whether this will work or not. How likely would it be for people to feel comfortable putting one on, or wearing them outside? Most people definitely enjoy gadgets but, as the smart-glasses episode showed us, they need to perceive it as ‘cool’ or they won’t ever succeed. Whether or not a robotic tail will ever be as socially acceptable as a cane remains to be seen but.

In the meantime, it definitely does look like a fun tail to try on.

The tail was presented at the SIGGRAPH ’19 conference in Los Angeles. A paper describing the work “Arque: Artificial Biomimicry-Inspired Tail for Extending Innate Body Functions” has been published in the ACM SIGGRAPH 2019 Emerging Technologies journal.