In this paper, we discuss the mechanism of detachment of thin pre-stressed films from a flat smooth rigid substrate. Indeed, we develop an analytical solution in closed form which shows how the critical value of the pull-off force strongly depends on the press-stress P0 . In detail, the critical pull-off force needed to detachment is shown to be higher for pre- stressed tapes. Furthermore, we notice that, when a high pre- stress is present, tapes may behave in different manner and spontaneously detach from the rigid substrate.

This paper presents a new mechanical architecturefor elbow powered myoelectric prostheses. New requirements for active prostheses are energetic autonomy, low production cost and human like behavior. On the scientific panorama very few examples of parallel device are available. We show an alternative device, with a simple mechanical hardware, to simulate the movements and the dynamic of human elbow. We investigated on wires used like tendons in mechanical elbow prostheses. The wire transmission architecture allows two linear actuators to control the motion of the forearm along two degrees of freedom in an enhanced work volume. The device, indeed, is designed to provide in the same mechanism flexion/extension and pronation/supination movement, which are usually decoupled in elbow and wrist mechanisms in usual commercial devices.