Researchers at Keio University in Japan have developed a wearable robotic tail called Arque a bio inspired device designed to help people maintain balance by mimicking how animals use tails to stabilize themselves.

The Arque tail, roughly one meter long and worn around the waist, functions like a pendulum that automatically shifts its weight in the opposite direction when the wearer leans or tilts, assisting with balance restoration feature particularly valuable for older adults with unsteady gait.

Powered by four pneumatic artificial muscles, the tail can move in eight different directions, responding to the user’s motion and helping maintain stability. The idea draws inspiration from animals whose tails act as natural balance aids, such as cheetahs and other vertebrates that counterbalance their bodies during movement. Although initially developed with elder care in mind, Keio researchers are also exploring industrial applications — such as assisting workers who need extra stability while carrying heavy loads or navigating uneven terrain.

This innovative device showcases how biomimicry and robotics can come together to support human mobility and safety in aging societies and demanding work environments, pointing toward a future where wearable robotic aids might become common in daily life.