In this paper we study controlled synchronization of interconnected robotic systems with dynamic uncertainty. It is first demonstrated that a previously developed algorithm for robust tracking  renders the closed loop system semi-passive. For the special case of two identical agents and in the absence of communication delays, the proposed control law ensures state synchronization for a large coupling gain. In the general case of heterogeneous agents communicating on balanced graphs, the control law guarantees ultimate boundedness of the synchro- nization and the tracking errors both in the delayed and the delay free case. Numerical examples are presented to verify the efficacy of the proposed control algorithms.