RoboHub: Exoskeletons typically use heavy electric motors, but lightweight actuators such as pneumatic muscles are now being considered. by Steve Davis
'These can produce similar forces to electric motors but at a fraction of the weight. The muscles consist of a rubber bladder surrounded by a woven sleeve. When pressurised, they increase in diameter and contract in length, pulling the joint. They are made from lightweight materials but can generate the force needed to lift many hundreds of kilogrammes.
'However, even these lightweight actuators still need to be attached to a rigid mechanical structure mounted to the user’s body. Myself and my colleagues at the University of Salford’s Centre for Autonomous Systems and Robotics are developing another alternative: soft robotics. This technology uses physically soft advanced materials to carry out similar tasks to traditional rigid robotic devices. They are particularly well suited to interaction with humans as they are typically lightweight which means if they collide with a person they are unlikely to cause injury.
'We recently developed a new “soft continuum actuator”, a joint that bends like an elephant’s trunk. Unlike a traditional rigid robot joint, if it encounters resistance in one part of its body it will still bend but at a different location elsewhere along its length.
'By equipping a skintight material suit with these actuators, we can create a soft exoskeleton that bends at the precise location of the wearer’s joints. This means the suit will fit a range of users comfortably without needing mechanical adjustment or calibration. Plus, the system is lightweight and can be worn like clothing rather than a bulky mechanical frame.'
"Forget Iron Man: skintight suits are the future of robotic exoskeletons" by Steve Davis here