Smart Adhesives via Magnetic Actuation

Abstract

Smart adhesives possess a wide range of applications owing to their reversibly and repeatedly switchable adhesion in transfer technology. Despite recent advances, it still remains a technical and scientific challenge to achieve strategies for rapidly tunable adhesion in a noncontact manner. In this study, a smart adhesive to achieve dynamically tunable adhesion is developed. Specifically, a mushroom‐shaped adhesive with a magnetized tip is actuated to reversibly and rapidly transform the morphology via magnetic actuation. The smart adhesive has two working modes, namely, selective pickup mode and pick‐and‐place mode. In the selective pickup mode, the external magnetic field is applied and the tip undergoes bending deformation. Changes in tip morphology allow for a reversible switch of the adhesion between “turn on” and “turn off.” In the pick‐and‐place mode, the external magnetic field is applied when the target object needs to be released. Upward bending deformation of the micro‐beam, a part of the tip, creates an initial crack at the edge of the adhesion interface. The propagation of the edge crack modulates the adhesion from strong to weak and the target object is instantly released. The proposed smart adhesive may be of interest for practical applications demanding highly precise and swiftly controlled movements.

Tunable Dry Adhesion of Soft Hollow Pillars through Sidewall Buckling under Low Pressure

“…The ability to modulate adhesion at interfaces is important for biological functions such as gecko's climbing on a vertical wall and industrial applications such as microtransfer printing. [1][2][3][4] This need has motivated the design of switchable adhesive systems with adhesion strength that can be controlled on demand by various stimuli, including mechanical forces, [5][6][7][8][9] magnetic field, [10][11][12][13][14][15] electric current, [16][17][18][19] pneumatics, [20,21] light, [22,23] and temperature. [24] In particular, gecko-inspired dry adhesive In this work, we introduce a class of soft hollow pillars (SHPs) containing a cylindrical sidewall sealed by a bottom contact membrane with highly tunable dry adhesion under low pressure (Figure 1).…”

Multi-responsive and programmable actuators made with nacre-inspired graphene oxide-bacterial cellulose film

“…[1][2][3][4][5] The physical stimuli can be electric, [6][7][8] light, 9 heat, 10 pressure, 11 and magnetism. 12 The chemical stimuli can be pH, 13 water vapor, 14,15 and other solvent vapor. 16 There are two main assembly methods for actuators.…”

All polymer‐based transparent composites for electrothermal actuator and supercapacitor

“…Actuating materials, a class of materials that can convert different types of energy into mechanical energy, have received extensive attention in recent years 1–3 . As a type of smart device, actuators can quickly respond to external stimuli such as humidity, 4 heat, 5 light, 6 magnetic field, 7 and chemicals 8 . Inspired by these unique properties, various types of actuators based on polymers, carbon‐based materials, and hydrogels have been designed and constructed to be applied in the fields of environment perception, target transportation, and bionic robotics 9–13 .…”