Smooth and slipless walking mechanism inspired by the open–close cycle of a beetle claw

Abstract

This study investigated the function of the beetle’s claw for its smooth and slipless walking and designed an artificial claw open–close cycle mechanism to mimic the beetle’s walking. First, the effects of claw opening and closing on beetles’ ability to attach to surfaces were examined. A beetle does not have an attachment pad, and only its claws work to grip the ground; its claw opens and closes and attaches with two sharp hooks. With their claws, beetles can smoothly walk, neither slipping on nor having their claws stuck in the surface. How do they perform smooth walking with sharp claws? In this study, we observed that beetles close their claws when they raise and swung their legs forward, while they open their claws when they lowered their legs to the ground. We then conducted non-destructive tests: their claws were forced open or closed. There was a significant difference in the trajectories of forced-closed claws compared to intact claws and forced-open claws. When their claws were forced-closed, this caused slippage in walking. On the other hand, when a claw was forced-open and its rotation was also inhibited, the claw stuck heavily in the surface, and the beetle could not walk. Based on these findings, we designed an artificial claw to open and close in the same cyclic manner as in the case of natural beetles. The performance of the artificial claw was consistent with the conclusions drawn from natural beetles: the locomotive robot with the artificial claw smoothly moved without slippage. Through these observations, non-destructive tests and performance of the bio-inspired artificial claws, this study confirmed the function of the open–close cycle of beetle claws and demonstrated and successfully adopted it for a locomotive robot.

Biohybrid robots: recent progress, challenges, and perspectives

“…The locomotion of these augmented animals can then be externally controlled, spanning three modes of locomotion: walking/running, flying, and swimming. Notably, these capabilities have been demonstrated in jellyfish (figure 4(A)) [139,140], clams (figure 4(B)) [141], turtles (figure 4(C)) [142,143], and insects, including locusts (figure 4(D)) [27,144], beetles (figure 4(E)) [28,[145][146][147][148][149][150][151][152][153][154][155][156][157][158], cockroaches (figure 4(F)) [159][160][161][162][163][164][165], and moths [166][167][168][169][170].…”

Cyborg Insects: Bug or a Feature?

“…Those solutions were mainly based on direct or indirect electrical stimuli. Other different types of actuators have been proposed based on: (i) thermal stimulus considering different species of beetles [39], (ii) optrodes to control the flight of dragonfly based on flexible waveguide arrays [40], (iii) biochemical molecules for muscle relaxation by a specific type of liposome [41] , (iv) plasmonic nanotattoos [42], (v) artificial claw open-close cycle mechanism [43], and (vi) explosive chemical vapors [44].. Actuation in cyborg insects poses ethical questions that have been systematically indicating in [45]. Different domains are identified and the effects of the media coverage is mapped, trying to indicate different types of application with their moral judgment.…”

Gripping performance in the stick insect Sungaya inexpectata in dependence on the pretarsal architecture

“…Functional morphology of their extremities and associated structures (Cruse 1976;Gorb 1996Gorb , 2001Gorb , 2005Federle et al 2001), as well as their locomotion control mechanisms (Koditschek et al 2004;Ijspeert 2008) are well studied and also contributed to bionics engineering (biomimetics) and modern robotics, in particular soft robotics (Kim et al 2013;Li et al 2016;Shintake et al 2018). Examples include a biomimetic robot based on both insect leg configuration (hexapodic) as well as their neuronal control mechanism (Bal 2021), hexapods based on soft robotic dielectric elastomer actuation (DEA) (Nguyen et al 2018) and a robot with a beetle claw inspired locomotion system using open and closed claw states for smooth and slipless walking (Shima et al 2020). Climbing robots such as one based on insect claws and tarsal spines (Liu et al 2019) have also been developed.…”