This paper addresses the design of a robotic hand by proposing the integration of a palm, which can adapt its shape. This feature has been specifically proposed to enhance the grasping adaptability for the envelope grasping of objects having different size and shape. The design process is proposed by addressing the kinematic analysis and synthesis of the proposed finger and palm mechanism to fit objects with maximum size ranging from 50 to 100 mm. A dynamic analysis is carried out as based on Lagrange formulation. A prototype is rapid prototyped and preliminarily tested in order to validate the feasibility and effectiveness of the proposed design.