In 1987, Richard Greenhill, a British photographer who was fascinated (but had no real training) in robotics, decided he wanted to build a life-sized humanoid that could do useful things, like carry luggage. He was working at a startup called Intergalactic Robots, but he couldn’t convince anyone there to build such a machine, so he started building it himself, in his attic.
To help with his project, he organized a weekly meeting of about a dozen like-minded people. Every Wednesday night, his wife, Sally, would cook a big pot of spaghetti, and the group would play with parts ripped from old printers and scavenged from junk yards. They call themselves the Shadow Team. They eventually built several different robots, but their main project was the two-legged Shadow Walker.
In 1987, photographer Richard Greenhill organized a weekly gathering of DIY enthusiasts to work on projects in his attic, including the Shadow Walker. Richard Greenhill and David Buckley
Greenhill’s friend David Buckley, a robotics and animatronics expert he had met at Intergalactic, drew up a rough design based on medical literature on human anatomy and muscle movement. The robot’s skeleton, made of maple, has been simplified—only one bone in the lower leg and one wide toe on each foot. The dual axis design of the ankle allows for two degrees of motion. The knee did not have a complex kneecap.
Greenhill didn’t want the robot to use motors, so its movements were controlled using compressed air to expand and contract 28 “air muscles”—his version of McKibben’s muscles, developed in the 1950s to simulate muscles with pneumatics. The muscles were attached to bones at all eight joints (hips, knees, ankles, toes), which provided 12 degrees of freedom.
The robot’s headless body housed control valves, electronics, and computer communications. It was 168 cm long and 46 cm wide and weighed 38 kg. The team was able to make the robot reliably stand up and balance itself; it can regain its center if pushed lightly. But traveling was a challenge.
Rich Walker joined the team at a young age and began writing software to make the robot stand. He was particularly interested in using neural networks to solve measurement problems, although he encountered many hardware obstacles, including the unreliability of sensors and valves, and the general fragility of the robot. Over time, Walker and his team developed a standard library of routines to control the robot. Walker wrote a detailed description of Shadow Walker in 1999, which is available on David Buckley’s website.
1st International Robot Olympics
By the time the Shadow Group began developing the Shadow Walker, academic and industrial engineers had been working with robotics for several decades. The world’s first industrial robot, the Unimate, debuted in 1961, and in 1967 Donald Michie and others began building a series of Freddy robots to investigate machine intelligence. The IEEE created its first dedicated robotics organization in 1984 when it established the IEEE Robotics and Automation Council, which became the IEEE Robotics and Automation Society in 1987. Also in 1987, the non-profit International Federation of Robotics was founded to promote research, development, application, and cooperation in the field of robotics.
As Shadow Walker pushes the limits of the DIY humanoid robot, industrial humanoids are also gaining ground. In 1986, Honda began working on its test (E-series) and later prototype (P-series) humanoid robots, finally unveiling the P2 in 1996. It was the first humanoid capable of steady, independent walking. This work eventually led to the development of ASIMO.
Greenhill’s friend, roboticist David Buckley, consulted the medical literature to create a humanoid design for Shadow Walker.Richard Greenhill and David Buckley
In the late 1980s, the public was fascinated and horrified by the power of robots. Businesses see robots as a way to increase productivity, while workers worry that they will take their jobs. Children saw them as wonderful toys, while disabled people embraced them as tools of freedom. Military experts hoped that robots would fight wars without endangering human soldiers, while politicians wondered if robots could finally vote. Philosophers thought that robots could challenge our notions of intelligence (and stupidity), while theologians had trouble worrying about the human race in a future dominated by robots.
The Shadow Walker’s simplified anatomy consisted of only one bone in the lower leg and one broad toe on each foot.Science Museum Group
Peter Mowforth, founder of the Turing Institute in Glasgow, noted these different views of robots when announcing the 1st International Robot Olympics, to be held on 27 and 28 September 1990 and hosted by the Turing Institute and the University of Strathclyde. The Olympics will bring together the world’s best robots and showcase them live.
Mowforth himself thought that all the competing theories of robotics were overblown. Immersed in machine learning research and robotics development, he knew firsthand the limitations of the state of the art: Robots rarely worked as intended, broke easily, and were disrupted by seemingly trivial problems. He envisioned the Robot Olympics as a place to test what the latest generation of robots can and can’t do.
At the 1990 Robot Olympics, held in Glasgow, Shadow Walker wore pants to hide his “air muscles” from his competitors.Adam Hart-Davis/Science Source
The call for participation was very open. Instead of having fixed categories for the competition, the organizers chose to see who applied for the competition and group them based on their desired abilities. In addition to selecting winners in individual events, judges will select an overall Olympic champion based on quality of hardware, complexity of behavior, and novelty. Other awards were given to new competitors, technology that demonstrates commercial potential, and design. In the end, more than 50 robots were installed, from a combination of universities, industries, and hobbyist groups from Canada, France, India, Japan, Mexico, the Soviet Union, the United States, the United Kingdom, and Yugoslavia.
There was a lot of disappointment. Trolleyman, a wheeled robot similar to a golf cart, failed to power up while carrying the Olympic torch through the streets of Glasgow. The crowd in the arena tripped over the many robots that were trained on flat, smooth floors only. David Buckley later concluded that events were too difficult, and that the Olympics did not advance development.
Yes, there were winners. In an unexpected triumph of long-time technology, a full-time 19th-century Japanese archer from the Museum of Automata in York, England, won gold in the javelin, beating opponents more than 100 years his junior. The overall Olympic champion was Yamabico, Shoji Suzuki of the University of Tsukuba, Japan, who won bronze in the obstacle course and gold in the wall track, but was disqualified from the speaking section for not speaking English.
The Shadow team had high hopes for the Shadow Walker. Unfortunately, however, it failed to take action, and the biped race was won by the Cardiff University Biped. Shadow Walker now resides in the collections of the Science Museum in London.
Legacy of the Shadow Walker
In 1997, a paying customer demand for a robotic leg forced the Shadow Group to go public and become a registered company. Shadow Robot is now Britain’s oldest robotics company. Rich Walker, who had left the Shadow Group to get a BA in mathematics and a diploma in computer science at the University of Cambridge, joined Shadow Robot in 1999 as technical director. Today he is the director of the company.
Shadow Robot focuses more on strong robotic hands than robotic walking. But the focus on hands is also a legacy of the Shadow Group. Walker recalls that the Shadow Group’s first humanoid hand in the late 1990s was impressive in its ability to pick up a pint of beer (a smooth-sided, thin-walled glass). Today, Shadow Robot’s hands are testbeds for dexterity. No more air muscles, instead actuators move each finger with precision. The classic model consists of 20 motors, which allow abducting and tilting movements with 24 degrees of freedom.
The Shadow Walker user wore a data suit that recorded his movements and allowed the robot to copy them.Richard Greenhill
In a recent blog post, Sejal Parsotomo, chief marketing officer at Shadow Robot, wrote that while humanoid robots are good for public relations, creativity is the key to success: A robot that can enter your factory may be impressive, but a robot that can reliably manipulate objects is revolutionary.
In its struggle to take more than a few steps, Shadow Walker demonstrated the inherent difficulty robots had in mastering even low-level skills. In August 2025, Beijing will host the World Robotics Games. Competing in sports such as gymnastics, soccer, and track and field events, as well as other “useful” tasks such as cleaning hotels and sorting medicine, these robots may have surrounded competitors in the first Robot Olympics 35 years earlier. However, much work is still needed to enable robots to navigate the human-made environment. Despite incredible progress, we are still nowhere near useful humanoid robots.
Part of a an ongoing series looking at historical artifacts that embrace the limitless power of technology.
An abridged version of this article appears in the June 2026 issue as “Learning to Walk.”
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