Positive pressure induced channeled suction cups

Abstract

Leaking in water pipe is a critical issue in Middle Eastern countries such as Kuwait where water is scarce. In-pipe robots can be dispatched to discover the network and inspect the inner surface of the pipe. This thesis describes the design and characterization of suction pads for in-pipe robots. The suction cups are made of hyperelastic materials that contain air channels inside. Instead of using conventional suction technique that is prone to leaking and loosing adhesion force, the suction cup is actuated by compressed air or liquid, which deforms the geometry of the cup to achieve suction. In order to verify the geometry changes during actuation, a uniaxial tension test was done on the elastic material used to acquire the material properties and the suction cup designs were then simulated using FEA in ABAQUS. Next, prototypes were designed in SolidWorks and fabricated using soft lithography techniques. To measure the suction force, pressure measurements were taken both inside the prototype channels and underneath the suction cup. Results show that a Positive Pressure Actuated Suction-cup (PPAS) of diameter forty millimeters can achieve suction force up to 68 N. As more air is inserted into PPAS, the suction force also increases. The concept has proved to be a feasible solution for pipe inspection robot.