Abstract-In this paper, sliding mode control is applied on Multi Input / Multi Output (MIMO) nonlinear systems. A novel approach is proposed that allows chattering reduction on control input, while keeping high tracking performance of the controller in steady state regime. This approach consists of designing a nonlinear reaching law by using an exponential function that dynamically adapts to the variations of the controlled system. Experimental study was focused on a MIMO modular robot arm. Experimental results are presented to show the effectiveness of the proposed approach, regarding especially the chattering reduction on control input in steady state regime.