Enhancements of Loading Capacity and Moving Ability by Microstructures for Wireless Soft Robot Boats

Because of its promising applications in various fields such as in vivo drug treatment, in-pipe inspection, and so forth, there is an increasing interest on wireless soft robot boats taking advantages of their shape adaptability. The loading capacity and mobility, however, are always fundamental challenges to restrict their applications. In this study, a graphene-based soft robot boat, which could be programmable-driven by a remote near-infrared light, is proposed. Different microstructures underneath the boat are carefully designed and employed to improve both the loading capacity and the moving ability. It reveals that, compared to that without microstructures, the soft robot boat with square pillar arrays (120-160 μm of period, duty cycle, and aspect ratio at active Wenzel/Cassie transition point) could enhance the loading capacity by 12.75% and the moving velocity by 16.70%. For the robot boat with grating structures, a strong driving anisotropy is revealed, with an enhancement of 2.24% for the loading capacity and 34.65% for the driving response along the grating lines. A boat prototype with a self-weight of 6.05 g is finally developed and can achieve continuous navigation in a closed narrow space for in situ monitoring, which may find applications in the inspection of other narrow terrains (e.g., blood vessels).