Japanese engineers have developed a wearable suit that supports human movement without requiring electronic devices or tanks.

In traditional assistive equipment, compressors and tanks are necessary to exert sufficient power to support human motion. These can be expensive to maintain and can limit the use of such devices.

Developed at Hiroshima University and Daiya Industry Co. Ltd., the Unplugged Powered Suit (UPS) uses a pneumatic gel muscle (PGM) as an actuator in a design intended to assist users of varying mobility.

The UPS consists of three parts: PGM (drive part), pump (air pressure for flexing artificial muscle) and pipework (transmission). Light and flexible, the drive part exerts supportive power via low air pressure. The pump is located on the contralateral sole, allowing the driving force to be transmitted to the PGM using human body weight.

The UPS comprises three parts: drive, pump and pipework. Image credit: Hiroshima University."This arrangement makes it possible to support human hip movement in the swing phase," says Yuichi Kurita, associate professor at the Institute of Engineering at Hiroshima University.

During use, the UPS carries out two functions: one is to decrease muscle activity during jogging and the other is to increase pitch speed. To decrease muscle activation during jogging, the PGM is equipped along the musculus soleus and the pump is affixed to the ipsilateral toe. To increase the pitch speed, the PGM is equipped along the greater pectoral muscle and the pump is affixed to the contralateral toe.

"The UPS is designed to support human motion where and when needed," says Kurita. "We can customize the UPS to the user's particular needs, such as muscle strength for athletes and rehabilitation."

Kurita says the technology will help pave the way for the development of smarter assistive suits that include wearable actuators and sensors.