A team of researchers at the University of Tokyo developed humanoid robots that are closely based on human anatomy. Other humanoids are made from rigid parts that limit their movement, but these new robots, called Kengoro and Kenshiro, have musculoskeletal systems with joints and tendon-like parts that bend and flex in a more realistic way.

They also have a sensory nervous system in the form of embedded sensors, plus a brain-like ability to use information (existing data) to perform actions without requiring explicit instructions from a human. The robots can do pushups, crunches, chin ups, calf raises and back extensions, and just like us, they sweat during their workout. True to their mission of recreating the human body, the researchers even designed an artificial perspiration system to release heat from the motors.

In a research paper published in the journal Science Robotics, the researchers wrote, "A limitation of conventional humanoids is that they have been designed on the basis of the theories of conventional engineering, mechanics, electronics, and informatics. They are also primarily intended for engineering-oriented applications, such as task achievement in daily life, personal assistance, or disaster response."

In contrast, they designed Kengoro and Kenshiro based on the human body's systems, with an end goal of providing a platform for future scientific research. The new humanoids could be very useful for any scientific research that involves the human body in motion. They are like detailed, realistic crash test dummies. In fact, crash testing is one potential application. Today's crash test dummies passively respond to motion in simulated car accidents, but an actual human being is more complicated. When faced with a sudden unexpected crash, we might clench our teeth, grip the steering wheel, and tense our muscles. A more detailed crash test dummy could help make safety testing more accurate.

Another potential area of research is athletics. Since the robots can move like humans, they could be used to study the best way to swing a bat or the ideal finger grip for throwing the fastest pitch. They could also help us understand how to prevent and treat sports-related injuries. The robots will be used to develop better artificial limbs, to grow human tissue grafs, and the researchers have even suggested a completely artificial body.

The researchers used human statistical data to build artificial body parts with perfectly humanlike proportions. They designed actuators that mimic the connections between muscles and tendons in human bodies, which allow for greater degrees of freedom at the joints and therefore more fluid motion than typical robots.