  Growing robots based on the eversion principle are known for their ability to
extend rapidly, from within, along their longitudinal axis, and, in doing so,
reach deep into hitherto inaccessible, remote spaces. Despite many advantages,
eversion robots also present significant challenges, one of which is
maintaining sensory payload at the tip without restricting the eversion
process. A variety of tip mechanisms has been proposed by the robotics
community, among them rounded caps of relatively complex construction that are
not always compatible with functional hardware, such as sensors or navigation
pouches, integrated with the main eversion structure. Moreover, many tip
designs incorporate rigid materials, reducing the robot's flexibility and
consequent ability to navigate through narrow openings. Here, we address these
shortcomings and propose a design to overcome them: a soft, entirely fabric
based, cylindrical cap that can easily be slipped onto the tip of eversion
robots. Having created a series of caps of different sizes and materials, an
experimental study was conducted to evaluate our new design in terms of four
key aspects: eversion robot made from multiple layers of everting material,
solid objects protruding from the eversion robot, squeezability, and
navigability. In all scenarios, we can show that our soft, flexible cap is
robust in its ability to maintain its position and is capable of transporting
payloads such as a camera across long distances.
