Exoskeletons – augmenting human capabilities

Since the dawn of civilisation, human endeavours have been directed towards improving human capabilities – possessing superhuman strength and running faster being primary aims. Exoskeletons have the potential to augment human capabilities, with the earliest reference to an exoskeleton occurring in US Patent 420179 published in the 1890s. The US Army had been the major investor in developing these technologies to improve the strength of soldiers. Further, General Electric and the US armed forces co-developed and tested an exoskeleton prototype named “HARDIMAN”. However, the exoskeleton could not be applied in real-life scenarios as it was heavy, restricted movements and had a limited power supply. Thanks to recent technological advances, it is now possible to reduce both the size of such suits and their energy consumption, and to closely imitate the movement of a human.

Apart from augmenting human capabilities, these suits have found another application in the medical field; namely, by enabling disabled people to walk and aiding the rehabilitation of stroke and spinal cord injury patients. As such, the medical industry is now the major investor and area of application for this technology.

In addition, exoskeletons have been applied in various other fields, including construction, manufacturing, logistics and search and rescue – mainly to reduce effort and fatigue, and to prevent injuries.

Japan, China and the United States are the major innovation hubs for this technology, with the United States being the biggest market. Key players working in the domain are:

• Honda Motor Company;
• Panasonic;
• Ekso Bionics;
• Cyberdyne;
• Rewalk Robotics;
• Bosch;
• Rex Bionics;
• Hyundai Motor Company;
• Wandercraft; and
• Parker Hannifin.

The exoskeleton market is expected to grow at an unprecedented rate as the technology is applied across various fields. Healthcare is the principal market for this technology, with an increasing geriatric population and awareness among patients as the key driving factors in the field. As many key industry players (eg, Ford) are using EksoVest (developed by Ekso Bionics) in their assembly lines, other players are likely to follow suit, as the technology provides benefits such as increased productivity and reduced fatigue and injuries in the case of construction and industrial applications.

Exoskeletons have also been applied in sports. Indeed, Ski~mojo was developed specifically for reducing leg pain and fatigue caused by skiing.

Although the technology is moving rapidly, there are a number of constraints with regard to its commercialisation; cost being the most significant. At present, lower extremities exoskeletons range from $70,000 to $120,000 – and that is just the cost of the device, excluding maintenance, spare parts, training and the cost of supervision. Other factors limiting the application of the technology include:

• the need for customisation of the suit as per the owner’s requirement;
• the heavy weight of the exoskeleton; and
• its constrained movements.

To overcome these constraints, some companies have developed soft exo-suits, powered by:

• muscle actuators;
• compressed air; or
• a flex or extend mechanism.

The road ahead

Science-fiction films and comics such as Iron Man have offered various depictions of exoskeletons. Although we are no closer to creating suits that can fly, provide superhuman strength and speed, or that are powered by a palm-sized nuclear reactor, we are moving in that direction and for now we must make do with the limited power supply of exoskeleton suits. With advances in material, battery and actuator technologies, these suits should improve and may be used in many other fields. In addition, it will be worth seeing how the increased use of three-dimensional (3D) printing technologies can help to create customised suits according to the owners’ requirements and what other benefits 3D printing may provide in the development of this technology.