Energy-recycling stairs could save people's old joints
2017-07-17 13:56:00

Researchers at two universities in Atlanta, Georgia, a state in the southeastern United States, have created a device that makes walking up and down stairs easier.

Detailed in a paper published in the journal

Public Library of Science PLOS ONE

, the spring-loaded device -- actually two steps of energy-recycling stairs -- stores a user's energy during descent and returns energy to the user during ascent.

It compresses when someone comes downstairs, saving energy otherwise dissipated through impact, and braking forces at the ankle by 26 percent.

When going up, the stairs give people a boost by releasing the stored energy, making it 37 percent easier on the knee than using conventional stairs.

Each stair is tethered by springs and equipped with pressure sensors. When a person walks downstairs, each step slowly sinks until it locks into place and is level with the next step, storing energy generated by the user.


A walk down the energy-recycling stairs /Georgia Tech Photo

It stays that way until someone walks upstairs. When a person steps on the sensor on the next tread up, the latch on the lower step releases, which in turn releases the stored energy and lifts up the back leg.

The device can be placed on existing staircases and doesn't have to be permanently installed.

Karen Liu, an associate professor in Georgia Institute of Technology's School of Interactive Computing, initially got the idea for the project when she attended a conference and saw an ankle brace that stored and released energy.

Her 72-year-old mother has no problems walking but has difficulty climbing steps, and Liu knew she wouldn't wear special sneakers just for stairs. So she decided to make smart stairs that act like the shoe.

Source: Xinhua Editor: Hiram