Robotic dog being worked on by a researcher. This robot is modelled on a greyhound. Instead of traditional electric motors, it uses pneumatic muscle actuator (PMA) technology. PMAs are soft tubes that can be contracted pneumatically to produce force. They have high power-to-weight ratios. They are also efficient and precisely controllable. The properties of PMAs are similar to those of natural muscles. This robot is part of a project to explore the potential of the technology. The field of engineering inspired by living things is called biomimetics. Photographed at the University of Salford, UK.