Development of an SMA driven articulation and autofocus mechanism for endoscope applications

In recent years, continuum robots are found more and more in industrial and medical applications, therefore the research interest in this field is continuously increasing. Conventional solutions have the disadvantage of bulky driving units placed at the base of the robot. These affect the weight, size, and mobility of the total system, even if this solution allows preserving the lightweight nature of the active part. This paper presents a novel shape memory alloy (SMA) wire-based concept of a fully integrated continuum robotic endoscope. The usage of these unconventional actuators, integrated within the flexible structure results in a compact and lightweight overall robotic structure. The mechanical design and assembly are presented. In addition, to complete a functional endoscope, the development of an SMA driven autofocus camera system is presented. In follow up projects, the autofocus will be integrable within the tip of the robot to allow an adjusting of the camera focus.