In this paper, we propose a new type of haptic interface, named active link mechanism. This device realizes Physical Man-machine Interaction (PMI) between machines and persons. Two prototypes were developed to demonstrate the potential of the active link mechanisms. Developed interface devices are an active tetrahedron and an active icosahedron. Nine-DOF micro spherical joints and pressure control pneumatic cylinders were developed to realize the active tetrahedron, while fifteen-DOF micro spherical joints and intelligent pneumatic cylinders were developed for the active icosahedron. The tetrahedron successfully realizes "virtual touch"; the operators feel actions, forces, and shapes of the virtual objects in PC and also move and deform them. Real time PMI is realized by building the developed devices into MSC.VisualNastran4D. MSC.Visual-Nastran4D is a mechanism analysis software, which can make motion analysis in real time. The active icosahedron also realized dynamic interaction with virtual objects in PC, showing the potential of the devices as a haptic interface.