Glowing Sucker Octopus (Stauroteuthis syrtensis)‐Inspired Soft Robotic Gripper for Underwater Self‐Adaptive Grasping and Sensing

Abstract

A soft gripper inspired by the glowing sucker octopus (Stauroteuthis syrtensis)’ highly evolved grasping capability enabled by the umbrella‐shaped dorsal and ventral membrane between each arm is presented here, comprising of a 3D‐printed linkage mechanism used to actuate a modular mold silicone‐casting soft suction disc to deform. The soft gripper grasp can lift objects using the suction generated by the pump in the soft disc. Moreover, the protruded funnel‐shaped end of the deformed suctorial mouth can adapt to smooth and rough surfaces. Furthermore, when the gripper contacts the submerged target objects in a turbid environment, local suctorial mouth arrays on the suction disc are locked, causing the variable flow inside them, which can be detected as a tactile perception signal to the target objects instead of visual perception. Aided by the 3D‐printed linkage mechanism, the soft gripper can grasp objects of different shapes and dimensions, including flat objects, objects beyond the grasping range, irregular objects, scattered objects, and a moving turtle. The results report the soft gripper's versatility and demonstrate the vast application potentials of self‐adaptive grasping and sensing in various environments, including but are not limited to underwater, which is always a key challenge of grasping technology.

Soft Microdenticles on Artificial Octopus Sucker Enable Extraordinary Adaptability and Wet Adhesion on Diverse Nonflat Surfaces

“…The microdenticle of the octopus can enhance interfacial interactions with the surfaces of various objects, [ 9b,c ] and the hierarchical structure in AOS‐sm shows a similar effect. The hierarchical structure of AOS‐sm is implemented using a relatively soft material ( E ≈ 10 kPa) [ 12a ] that shows suitable adaptability to various surfaces. In addition, numerous microdenticles enhance the interactions with irregular interfaces through suction and capillary effects.…”

“…The AOS cup (diameter 3.2 cm and height 2 cm) with soft microdenticles was fabricated through a series of facile replica molding processes. According to previously reported methods, the two base molds were sealed together, silicone precursor Dragon Skin 10 ( E ≈ 300 kPa) was deposited, [ 12a ] and then the top mold was attached to form a void dome ( Figure 2 a ). After curing the AOS‐sm body and disassembling from the molds, the microdenticles were replicated by thinly coating the surface of the AOS with an even softer silicone precursor, Ecoflex10 ( E ≈ 10 kPa), [ 12a ] and then applying the AOS to a polyurethane‐acrylate (PUA)‐based mold with the reverse architecture of the microdenticles (Figure 2b and Figure S1 , Supporting Information).…”

“…According to previously reported methods, the two base molds were sealed together, silicone precursor Dragon Skin 10 ( E ≈ 300 kPa) was deposited, [ 12a ] and then the top mold was attached to form a void dome ( Figure 2 a ). After curing the AOS‐sm body and disassembling from the molds, the microdenticles were replicated by thinly coating the surface of the AOS with an even softer silicone precursor, Ecoflex10 ( E ≈ 10 kPa), [ 12a ] and then applying the AOS to a polyurethane‐acrylate (PUA)‐based mold with the reverse architecture of the microdenticles (Figure 2b and Figure S1 , Supporting Information). After curing in an oven at 60 °C for 1 h and disassembling from the PUA mold, the AOS‐sm was combined with a rigid, specially designed 3D‐printed structure that can apply pneumatic pressure, thus allowing the AOS‐sm to adhere to various objects with high adaptability.…”

“…To date, various octopus‐inspired soft devices with switchable attachment capabilities have been reported. [ 7 , 12 ] However, the actuation mechanisms of such soft adhesive devices (e.g., magnetic or electro/photoactive mechanisms and vacuum chuck systems) are impractical for use in aqueous environments and difficult to integrate into soft machines and actuators that perform complex functions. A recently developed controllable adhesive device simulates the attachment ability of an octopus sucker by inducing the actuation of a soft dome structure.…”

“…A recently developed controllable adhesive device simulates the attachment ability of an octopus sucker by inducing the actuation of a soft dome structure. [ 12a ] Nevertheless, owing to the absence of a hierarchical micro/nanoscale architecture at the contact interface, this system cannot achieve switchable adhesion to rough, irregular, or soft surfaces.…”