Elastic Energy Storage Enabled Magnetically Actuated, Octopus‐Inspired Smart Adhesive

Abstract

Octopus suckers offer remarkable adhesion performance against nonporous surfaces and have inspired extensive research to develop artificial adhesives. However, most of existing octopus‐inspired adhesives are either passive without an actuation strategy or active but not energy efficient. Here, a novel design of a magnetically actuated, energy‐efficient smart adhesive with rapidly tunable, great switchable, and highly reversible adhesion strength inspired by the elastic energy storage mechanism in octopus suckers is reported. The smart adhesive features two cavities separated by an elastic membrane with the upper cavity filled with magnetic particles while the lower one empty. The deformation of the elastic membrane can be actively controlled by an external magnetic field to change the cavity volume, thus generating a cavity‐pressure‐induced adhesion. Systematically experimental and theoretical studies reveal the fundamental aspects of design and operation of the smart adhesive and give insights into the underlying adhesion mechanisms. Demonstrations of this smart adhesive in transfer printing and manipulation of various surfaces in both dry and wet environments illustrate the potential for deterministic assembly and industrial or robotic manipulation.

A Smart Patch with On‐Demand Detachable Adhesion for Bioelectronics

“…Subsequent work found that the reversible adhesion can be realized by imitating ratchet-like attachment mechanism of climbing plants. [18] Recently, smart adhesives inspired by natural animals have been developed, such as the magnetically actuated elastic energy storage adhesives inspired by octopus suckers, [19] the gecko inspired wedged surface utilized for dry adhesion, [20] tree frog inspired hierarchical structure, and insect inspired fibrillar pads for enhanced wet adhesion [21,22] and mussel inspired tissue adhesive hydrogel for sensors. [23] Despite extensive studies on artificial adhesives, they often need to introduce nondegradable cross-linking agent along with complex and time-consuming manufacturing process.…”

Interfacial Liquid Film Transfer Printing of Versatile Flexible Electronic Devices with High Yield Ratio

“…[ 41 ] In this process, the device is transferred by adjusting the interface strength. [ 42,43 ] To increase the transfer printing yield rate, different materials and structures have been used, such as stamps with reversible boundary tips, [ 44 ] temperature‐response microstructures, [ 45 ] magnetically actuated microstructures [ 46 ] gecko feet‐like microstructures, [ 47 ] and stamps made of water response hydrogels. [ 48 ] For a better contact mode, Corbett et al.…”

Hydraulically Coupled Dielectric Elastomer Actuators for a Bioinspired Suction Cup

“…Dexterous cephalopods with soft arms and distributed suction cups provide bionic solutions since they can adsorb and release wet and dry objects in different sizes and shapes with ease [1][2][3][4]. In recent years, many researchers have been devoted to designing and fabricating novel bio-inspired suction cups [5][6][7][8][9][10][11][12][13][14][15][16]. Nguyen et al [5] fabricated an adhesive pad covered by a distributed passive suction cups array, which showed a three-times higher suction force than the theoretical limit, available for both dry and wet surfaces.…”

“…To grasp objects of irregular shapes and in confined environments, Mazzolai et al [9] designed and fabricated a soft arm mimicking octopuses' tentacles, which consists of an elastic arm made by polydimethylsiloxane and a pneumatically actuated suction cup array. Besides the conventional passive and fluid actuated suction cups, some researchers attempted to employ new actuation mechanisms [11,[15][16][17]. Lee et al [11] fabricated micro suction cups, of which the inner chamber is covered by temperature-sensitive hydrogel, Polymers 2021, 13, 3481 2 of 12 changing the chamber volume under different temperatures and reversely switching the adhesive force.…”

“…Hu [15] introduced a shape-memory-alloy spring to control the suction cup chamber volume, which could be adjusted by the heating or cooling of an electric coil. Wang et al [16] employed magnetically sensitive materials to change the volume of a suction cup chamber, which achieved a fast-response adhesion and high energy efficiency, within a comparably compact size.…”