man,” Walker told LiveScience during an interview. But it's not as simple as connecting everything like Tinkertoys. “You put a prosthetic part on a human who is missing that part,” Walker said. “We had no human; we built a human for the prosthetic parts to occupy.”

The robot, which cost almost $1 million to build, was modeled in some physical aspects after Bertolt Meyer, a social psychologist at the University of Zurich, in Switzerland, who wears one of the world's most advanced bionic hands.

The bionic man has the same prosthetic hand as Meyer – the i-LIMB made by Touch Bionics – with a wrist that can fully rotate and motors in each finger. The hand's grasping abilities are impressive, but the bionic man still drops drinks sometimes.

“He's not the world's best bartender,” Walker said.

The robot sports a pair of robotic ankles and feet from BiOM in Bedford, Mass., designed and worn by bioengineer Hugh Herr of MIT's Media Lab, who lost his own legs after getting trapped in a blizzard as a teenager.

To support his prosthetic legs, the bionic man wears a robotic exoskeleton dubbed “Rex,” made by REX Bionics in New Zealand. His awkward, jerky walk makes him more Frankensteinian than ever.

2.18. Factory-made organs

But it doesn't end there – the bionic man also has a nearly complete set of artificial organs, including an artificial heart, blood, lungs (and windpipe), pancreas, spleen, kidney and functional circulatory system.

The artificial heart, made by SynCardia Systems in Tucson, Ariz., has been implanted in more than 100 people to replace their ailing hearts for 6 to 12 months while they wait for a transplant, Walker said. The circulatory system, built by medical researcher Alex Seifalian of University College London, consists of veins and arteries made from a polymer used to create synthetic organs of any shape.

While it might not satisfy the Scarecrow from “The Wizard of Oz,” the bionic man's “brain” can mimic certain functions of the human brain. He has a retinal prosthesis, made by Second Sight in Sylmar, Calif., which can restore limited sight in blind people. He also sports a cochlear implant, speech recognition and speech production systems.

The engineers equipped the bionic man with a sophisticated chatbot program that can carry on a conversation. The only problem is, it has the persona of

“an annoying 13-year-old boy from the Ukraine,” Walker said.

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The most unnerving aspect of the bionic man, though, is his prosthetic face. It's an uncanny replica of Meyer's face. In fact, when Meyer first saw it, he hated it, describing it on the show as “awkward.”

The bionic man successfully simulates about two-thirds of the human body. But he lacks a few major organs, including a liver, stomach and intestines, which are still too complex to replicate in a lab.

The bionic man brings up some ethical and philosophical questions: Does creating something so humanlike threaten notions of what it means to be human? What amount of body enhancement is acceptable? And is it wrong that only some people have access to these life-extending technologies?

The access issue is especially troublesome, Walker said. “The preservation of life and quality of life has become basically a technical question and an economic question.”

The bionic man made his U.S. debut at New York Comic Con Oct. 10–13, and he was on display at Smithsonian's National Air and Space Museum in Washington, D.C.

2.19. The future of bionics could yield soft robotics and smart trousers

The word “bionic” conjures up images of science fiction fantasies. But in fact bionic systems – the joining of engineering and robotics with biology (the human body) – are becoming a reality here and now.

Getting older and less steady on your feet? You need a bionic exoskeleton. Having difficulty climbing those stairs? Try a pair of bionic power trousers. The biggest challenge for making these bionic systems ubiquitous is the huge range of situations we want to use them in, and the great variation in human behaviours and human bodies. At the moment there is simply no one-size-fits-all solution.

So, the key to our bionic future is adaptability: we need to make bionic devices that adapt to our environments and to us. To do this we need to combine three important technologies: sensing, computation and actuation.

Sensing can be achieved by using sensors which directly record brain, nerve and muscle activity, and by using on-body devices such as accelerometers which indirectly measure the movement of our limbs. Computers then link this information with models of human behaviour – often tailored to personal information about how the user moves – and predict the movements that the user is about to initiate. In the final stage, the computer systems use these predictions to divert energy to a set of power actuators. This actuation step provides the needed assistance and support, continually adapting to our changing bodies and the changing environment.

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At present, most bionic assist devices are made from rigid materials such as metals and plastics, and are driven by conventional motors and gearboxes. These technologies are well established but their hardness and rigidity can be a great disadvantage. In nature, soft materials such as muscles and skin predominate, and as humans we find comfort in soft materials, such as holding hands or sitting on a sofa.

2.20. Soft robotics for bionic bell-bottoms

New “soft robotic” technologies are emerging which have the potential to overcome the limitations of conventional rigid bionics. These systems, as their name suggests, employ soft and compliant materials that work more naturally with the human body. Instead of rigid metals and plastics, they use elastic materials, rubbers and gels. Instead of motors and gearboxes, they're driven by smart materials that bend, twist and pull when stimulated, for example by electricity.

These smart materials can mimic the contractions of biological muscles, and are often termed “artificial muscles”. With these advances we are now in a position to create radically new adaptive bionic devices for assistance and rehabilitation, including the smart bionic trousers.

The Engineering and Physical Sciences Research Council recently announced £5.3 m investment into research targeted at the next generation of adaptive bionic devices. This includes funding for the development of soft robotic smart trousers that will help disabled and elderly people to maintain their mobility and independence.

The goal of the smart trousers project – a major collaboration between the Universities of Bristol, Leeds, Nottingham, Southampton, Strathclyde, Loughborough, and the West of England – is to demonstrate the feasibility of fully autonomous smart clothing. The smart trousers would be able to monitor the wearer’s intentions and give automatic power assistance when needed, for example when getting up from a chair or when climbing stairs.

Of course, this is more than just a technology exercise. The soft robotic clothing will need to be comfortable, easy to put on, hygienic and stylish. These are important considerations that need the direct input of the end users and this project will consult closely, throughout its duration, with the target end users and clinical experts.

The future of smart trousers may lie in even tighter integration with the human body. By implanting sensors under the skin that monitor nerve signals directly, even more precise information about the user’s intentions can be measured. This will enable future devices to have a much more natural relationship with the wearer.

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The potential of this approach has been shown in the recent work by the Medical University of Vienna, where three patients with serious hand injuries volunteered to have their hands amputated and replaced with functional prosthetic hands controlled by their own nerve signals. They were then able to perform more sophisticated manipulations with everyday objects then they were before thetransplants.

These exciting new technologies look to herald a new era of soft robotic wearable bionic devices for assistance and rehabilitation which work in harmony with, and adapt to, our frail human bodies.

2.21. Bionic Exoskeleton: History, Development and the Future

Inspired by science fiction, that has very persuasively been brought out in books and movies, researchers have, for quite some time, put in efforts to make an effective exoskeleton which can be used for assistance. In this paper the history and development of exoskeletons will be discussed, but before it is necessary to define what an exoskeleton means.

For the purpose of this review, an exoskeleton is considered to be an active mechanical device which is anthropomorphic in nature, and can be worn by a person and can act as an assistive device. In this paper, our focus is more on exoskeletons for the lower extremities and exoskeleton as an assistive device for rehabilitation. This is mainly because when we take a look around us, we realize that a small accident might lead to devastating results such as fractures, brain injury, spinal cord injury or at times even death. In worst case scenario, a person becomes a victim of paraplegia, which may lead to loss of locomotion.

Such persons may never be able to walk again.

To uncover the major developments in the field of exoskeleton technology, we shall briefly touch upon performance augmenting exoskeletons followed by exoskeletons for rehabilitation. Then we provide some food for thought as to where we can put in efforts to speed up development and on how bright the future of exoskeletons is.

Most of the early work related to exoskeletons were concept studies that were put on the drawing board, but never actually built or tested. The earliest mention of a device resembling an exoskeleton was Yagn’s running aid patented in 1890. It was a simple bow/leaf–spring operating parallel to the legs and was intended to augment running and jumping.

Each leg spring was engaged during the foot contact to effectively transfer the body’s weight to the ground and to reduce the forces borne by the stance leg.

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During the aerial phase, the parallel leg spring was designed to disengage in order to allow the biological leg to freely flex and to enable the foot to clear the ground.

In the late 1960s, General Electric Research (Schenectady, NY), with Cornell University and financial support from the U.S. Office of Naval Research, constructed a full-body powered exoskeleton prototype.

Dubbed “Hardiman” (from the “Human Augmentation Research and Development Investigation”), the exoskeleton, was an enormous hydraulically powered machine (680 kg, 30 DOFs), that included components for amplifying the strength of the arms (including hands but without wrists) and legs of the wearer. It proposed to amplify the human strength drastically (25:1).

The pioneering work done with exoskeletons by Miomir Vukobratovic and his associates at the Mihailo Pupin Institute in Belgrade in the late 1960s and 1970s is one of the most extensive to date. They started with the “kinematic walker,” featuring a single hydraulic actuator for driving the hip and the knee, which were kinematically coupled. In 1970, the so-called “partial active exoskeleton” was developed, which used pneumatic actuators for flexion/extension of hip, knee, and ankle, as well as an actuated abduction/adduction joint at the hip for greater stability in the frontal plane. This concept was later modified slightly into the “complete exoskeleton” by extending the attachment at the torso to enclose the entire chest of the patient, providing greater trunk support. More than 100 clinical trials were performed with this device, and a number of patients with varying degrees of paralysis mastered walking using the complete exoskeleton with support from crutches. The total weight of the “complete” exoskeleton, after incorporation of lighter valves, was 12 kg. This value does not include the power source and control computer, which are not located on the device. Later a set of three piezo-ceramic force sensors were soon incorporated into the sole of the “complete” exoskeleton foot for use in determining the location and magnitude of the ground reaction force, which, in turn, was used for control of the device. In order to address the problem of being energetically autonomous, a version of the exoskeleton actuated by dc motors was developed. Although the limitations of the then motor, battery and computer technology marginalized the true portability of the device, this new actuation scheme offered further improvements such as smoother motion and better tracking ability.

Alongside there was a deep interest developed which led to extensive research in the field of exoskeletons. The United States came up with its much talked about Defence Advanced Research Projects Agency (DARPA) program which invited heavy funding for research related to exoskeletons. BLEEX, Sarcos, MIT Exoskel-

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