Early Developments of a Novel Smart Actuator Inspired by Nature

Current research at Imperial College focuses on the development of a novel neurosurgical probe for Minimally Invasive Surgery (MIS), which can be used to target deep lesions in the brain by exploiting the unique design of certain ovipositing wasps. While conventional neurosurgical instruments are rigid and can only be used to achieve straight-line trajectories, the biomimetic design will enable curved paths connecting any entry point to any target within the brain to be followed autonomously. This paper reports on the successful outcome of an early feasibility study, where two of the key concepts behind the novel actuator design are investigated: a biologically inspired robotic actuator was developed to demonstrate effective soft tissue traversal (i.e. motion along the surface of a soft tissue) by reciprocating custom-built anisotropic surface textures, without the need to apply an external force to push the tissue along the surface. Then, custom-designed rigid probes with bio-inspired surface topographies were fabricated and tested on cadaveric porcine brain with the aim to characterize the insertion and extraction forces due to friction and tribological interaction with biological tissue.