Powered exoskeletons are wearable external frames, they assist the wearer by augmenting the effect of their own strength and by reducing the impact of loads on the body thus increasing their endurance.
The applications for this technology are widespread but a lot of progress has been made due to military input. The ‘HULC’ (Human Universal Load Carrier) is an exoskeleton developed by Ekso bionics and license to Lockheed Martin, it is designed to be worn by soldiers to increase their load carrying ability – it enables the wearer to carry an extra 90kg (Lockheed Martin, 2012), the weight of which is transferred through the exoskeleton into the ground. Sensors in the foot pads send information to a microcomputer which drives the hydraulic actuators to move the suit as required. The HULC is non-autonomous, but research is being done into suits which can act autonomously if the wearer is injured – in order to get them to safety.
In the civilian world, the ‘ReWalk’ exoskeleton made by 3D Systems and EksoBionics is a mind controlled exoskeleton for helping paralysed people walk again, it is powered by a battery which can currently last for up to 2 hours and the parts are move by hydraulic actuators. The equipment uses a tilt sensor, when the wearer tilts forward the exoskeleton begins to walk – in this way the technology mimics natural walking (Rewalk Ltd, 2014). There are also sensors in the footplates which send signals via a microcomputer to feedback actuators which stimulate an area that the wearer can feel such as an arm.
The ‘Body extender’ exoskeleton by the Perceptual Robotics Laboratory is another exoskeleton, it has 22 degrees of freedom (Neil Bowdler, 2014) to closely mimic and augment the human body. All joints are actuated by electric motors powered by electricity from a mains power line. It is designed to be used in areas where flexibility is key such as search and rescue situations. Again the exoskeleton has no autonomy, the wearer is in full control.
Exoskeleton prototypes are currently being evaluated and proving to work well, the main constraint is the high power consumption, “The evolution of the exoskeleton will go hand in hand with the evolution of batteries or other high density storage systems as well as lightweight structural materials.” (Neil Bowdler, 2014).
Initially only larger organisations like the military will be able to afford exoskeletons. In the near future it is likely that lighter, partial body exoskeletons will become commercially available, such as those for single limbs – these can help provide physiotherapy. As the military begin to roll out the technology they will likely look for improved connectability to aid teamwork.
As production increases costs will decrease and the exoskeletons will become more widely available. Surgeons will be able to perform surgery with greater accuracy as exoskeletons compensate for unsteadiness caused by the pressure the surgeons are under. Firefighters and search and rescue teams will be able to move with greater flexibility with the heavy weight of their equipment.
Safety is a concern with all new inventions, ISO standards are being developed and cost will keep the number of people with access to exoskeletons limited at first. It is inevitable though, as the technology becomes more widely available that society will find ways to use it for criminal gain, exoskeletons could help thieves to carry more, fight better or run faster from the crime scene, this will no doubt create a need for the police to match the equipment. There are dangers when you consider operators who may be drunk or in a temper but it is likely that the positives – such as enabling people to walk again, saving more lives with search and rescue and greater productivity, will outway the negatives.