Prof. Vimalesh Muralidharan

Globally, my research focuses on designing robots that can safely interact with human beings. This feature inherently requires their moving elements to be light and compliant. Among the several approaches to designing such systems, I am motivated by nature/biology, e.g., the limbs of human beings. Although existing anthropomorphic robots appear to be inspired by human arms, they differ considerably in their joint design and actuation scheme. While robotic arms are constructed with revolute/prismatic joints actuated by heavy motors, natural arms have rolling contacts between bones driven by antagonistically arranged muscles. The former design restricts the motion capabilities and makes the moving structure heavy, thereby causing a fundamental difficulty in designing for lightness.

In our research group, we explore new types of joints, e.g., four-bar mechanisms, whose kinematics is equivalent to pure rolling between curves, and actuate them with antagonistic cables driven by motors fixed at the base. This new design paradigm takes us one step closer to biological systems and appears more promising for realizing our goal. We believe that it can demonstrate human-like features such as variable stiffness, safe contacts, and energy efficiency, which are very difficult for conventional robots to achieve.