This paper describes the development of an active clamping mechanism to be integrated into a swallowable pill for the diagnosis of the gastrointestinal (GI) tract. The clamping system allows to stop the pill in desired sites of the GI tract for long monitoring purposes. After discussing the major technical constraints, the design of the clamping system, based on FEA (Finite Element Analysis), is illustrated as well as its fabrication process. The clamping unit is actuated exploiting Shape Memory Alloys (SMA), in wires and spring configuration, and it is driven by a dedicated electrical interface. A fine tuning has been performed in order to limit the power consumption. Then a working prototype is fabricated and preliminarily tested, pointing out a capability of the grasping system over 40 g.

This paper presents the design and development of a microrobot which aims to replicate the locomotion principle of earthworms. The undulatory locomotion of living earthworms has been investigated deeply from the biological point of view, but attempts at replication of earthworm models in real size are limited. The authors have designed an artificial earthworm with four modules which can be driven independently according to defined undulatory patterns with a typical frequency of 0.5 Hz. Each module is actuated by one or more SMA springs whose configuration has been designed in order to limit wiring problems and optimize working frequency. The robot is covered by a shaped silicone material which can be used as a platform to insert tiny legs for obtaining differential friction conditions. Preliminary tests demonstrate that the earthworm prototypes can move with a speed of 0.22 mm/s, thus approximating the behavior of biological earthworms.

This paper illustrates the analysis of locomotion in the gastrointestinal tract obtainable by a legged capsule for diagnostic and therapeutic purposes. A preliminary simulation of the legged locomotion onto slippery and deformable substrates has been performed and -simultaneously - mechanisms for on board actuation of the legs have been developed and tested. Moreover, an engineering translation of medical needs in endoscopy is presented, with some ad hoc solutions for improving diagnostic capabilities.

This paper illustrates a mechanism specifically designed for locomotion in the wet, collapsible and tortuous human gastrointestinal (GI) tract (the colon in particular). Previous works performed in the authors' laboratory were devoted to the fabrication of semi-autonomous inchworm locomotion devices for navigation in the colon; in this paper a further analysis of limitations and problems of these devices has been performed. The main limitation consists of the poor efficiency of these devices to negotiate acute bends (due to what the authors termed as the "accordion effect") and, in general, to advance in the scarcely supported colon tissue. Thus a different approach to locomotion has been developed based on "sliding clampers". This locomotion principle has been implemented in a minirobot system and has demonstrated (both theoretically and experimentally) to be effective in reducing the "accordion effect".

In this paper the authors illustrate the development of a semi-autonomous robot for colonoscopy. In particular they focus on two problems: the generation of an effective and reliable advancement in the colon, and the possibility to steer the robot in order to overcome acute intestinal bends. Both problems are present also during traditional colonoscopy, but they can be solved with an external pushing action produced by the endoscopist. The main feature of this work is the attempt to replicate the effects of external forces (generated by the medical doctors) by using just internal actions (generated by the robotic devices). The robotic solutions and the mechanisms illustrated in this paper could be in principle integrated in an "all inside" device, with electrical wires and service tubes, but without structural cables or rigid tails which are currently used for the advancement and orientation of traditional colonoscopes.