Improving controllable adhesion on both rough and smooth surfaces with a hybrid electrostatic/gecko-like adhesive

Abstract

This paper describes a novel, controllable adhesive that combines the benefits of electrostatic adhesives with gecko-like directional dry adhesives. When working in combination, the two technologies create a positive feedback cycle whose adhesion, depending on the surface type, is often greater than the sum of its parts. The directional dry adhesive brings the electrostatic adhesive closer to the surface, increasing its effect. Similarly, the electrostatic adhesion helps engage more of the directional dry adhesive fibrillar structures, particularly on rough surfaces. This paper presents the new hybrid adhesive's manufacturing process and compares its performance to three other adhesive technologies manufactured using a similar process: reinforced PDMS, electrostatic and directional dry adhesion. Tests were performed on a set of ceramic tiles with varying roughness to quantify its effect on shear adhesive force. The relative effectiveness of the hybrid adhesive increases as the surface roughness is increased. Experimental data are also presented for different substrate materials to demonstrate the enhanced performance achieved with the hybrid adhesive. Results show that the hybrid adhesive provides up to 5.1Â greater adhesion than the electrostatic adhesive or directional dry adhesive technologies alone.

Morphological studies of the toe pads of the rock frog,Staurois parvus(family: Ranidae) and their relevance to the development of new biomimetically inspired reversible adhesives

“…More generally, studies on bioinspired adhesive materials are increasingly combining materials with very different properties in the development of new hybrid adhesive surfaces (e.g. [52,53]). In respect of the frog adhesion research, possible applications include improved design in wet weather tyres [35,54,55], non-slip footwear, plasters for surgery able to adhere to tissue, holding devices for surgery and the assembly of functional elements in miniature electronic devices (microelectromechanical systems).…”

Switchable Adhesives for Multifunctional Interfaces

“…[162,170] This approach has been particularly effective in robotic systems. [163,174] Hybrid approaches utilize a combination of interfacial and electrostatic forces have the advantage in that the substrate adheres after the electric potential is removed. [163,174] Hybrid approaches utilize a combination of interfacial and electrostatic forces have the advantage in that the substrate adheres after the electric potential is removed.…”

“…[171][172][173] Electroadhesion can also be used in a hybrid manner where typical elastomer adhesion and electrostatic forces can be combined. [163,174] Hybrid approaches utilize a combination of interfacial and electrostatic forces have the advantage in that the substrate adheres after the electric potential is removed. [169] This can be useful for climbing robotics that can peel to release, but does present limitations for rapid switching.…”

High strength reversible adhesive closures

“…Recent research has focused on bio‐inspired adhesives, such as those possessed by the gecko, because they demonstrate an ability to achieve high binding strength with easy release and are extensively reusable . Fibril‐based adhesives have been developed from a wide range of materials including elastomers, polyolefins, and carbon nanotubes, and while these materials can sustain high stresses, they often cannot scale to support large loads . There have been some limited attempts to use these materials as adhesive closures .…”

“…[7][8][9][10][11] Fibril-based adhesives have been developed from a wide range of materials including elastomers, polyolefins, and carbon nanotubes, and while these materials can sustain high stresses, they often cannot scale to support large loads. [12][13][14][15][16][17][18][19][20] There have been some limited attempts to use these materials as adhesive closures. [21][22][23][24][25][26] Despite superficially appearing similar to hook-and-loop closures, fibril-based adhesive closures achieve reversible loading conditions primarily due to Van der Waals interactions, not physical interlocking.…”