Shoe soles for the gripping robot: Searching for polymer-based materials maximising friction

The development of light-weight climbing robots capable of operating in various environments is a growing area in robotics. That is why there is a strong need for new tribologically-optimised materials at their gripping devices that may lead to the enhancement of the attachment force while reducing energy expenditure. Since insects are equipped with a set of very efficient attachment systems, enabling them to grip a variety of substrates, they may provide approaches for the innovation of climbing robots’ grippers. The goal of our study was a broad screening of polymeric materials to find out those with similar structure and functional principles to biological examples known from insect smooth attachment systems. Friction, adhesion and stiffness measurements were carried out. Rubber foamy materials covered with thin polymeric films and sandwich-like materials provided excellent compliant properties and the best performance in experiments (friction coefficients up to 3.2).