Signature Robot, a cooperative haptic robot, has been developed to demonstrate surgical robots can have a reduced operational footprint whilst maintaining sufficient accuracy and haptic capabilities. This novel platform allows low and even impedance motion across 3 degrees of freedom, namely rotation about pitch and yaw, and axial motion along a linear axis. It can achieve a rotational range of 120° along pitch and yaw, whilst linear motion can extend by up to 100mm, thus providing a sufficient workspace for unicondylar knee arthroplasty.

Kinematic calibration confirmed an average positional accuracy of 0.82 mm. Viscoelastic constraints could output forces up to 18 N and the robot could apply these directional forces anywhere within its 4700 cm³ working volume.