Toughening and asymmetry in peeling of heterogeneous adhesives

Shuman Xia (1) , Laurent Ponson (2) , Guruswami Ravichandran (3) , Kaushik Bhattacharya (3)

1 Woodruff School of Mechanical Engineering
2 DALEMBERT - Institut Jean Le Rond d'Alembert
3 EAS - Division of Engineering and Applied Science [Pasadena]

The effective adhesive properties of heterogeneous thin films are characterized through a combined experi- mental and theoretical investigation. By bridging scales, we show how variations of elastic or adhesive proper- ties at the microscale can significantly affect the effective peeling behavior of the adhesive at the macroscale. Our study reveals three elementary mechanisms in heterogeneous systems involving front propagation: (i) patterning the elastic bending stiffness of the film produces fluctuations of the driving force resulting in dramatically en- hanced resistance to peeling; (ii) optimized arrangements of pinning sites with large adhesion energy are shown to control the effective system resistance, allowing the design of highly anisotropic and asymmetric adhesives; (iii) heterogeneities of both types result in front motion instabilities producing sudden energy releases that in- crease the overall adhesion energy. These findings open potentially new avenues for the design of thin films with improved adhesion properties, and motivate new investigation of other phenomena involving front propagation.

Mots clés: Peeling; front propagation; heterogeneities; toughening

Domaines: Mécanique des solides [physics.class-ph]; Mécanique des solides [physics.class-ph]

Shuman Xia, Laurent Ponson, Guruswami Ravichandran, Kaushik Bhattacharya. Toughening and asymmetry in peeling of heterogeneous adhesives. Physical Review Letters, 2012, pp.1. ⟨hal-00679584⟩