Adhesives for "debonding-on-demand": Triggered release mechanisms and typical applications

Pressure sensitive adhesives (PSAs) are utilized for temporary applications since bonding and debonding are determined by the adhesive-substrate interface and the mechanical and rheological properties of the PSA. Moreover, a wide variety of basic materials allows for proper adjustment of the adhesive properties (tack, peel adhesion, cohesion). Where the adjustment of the adhesive's chemical composition is not efficient enough to provide easy and clean removability in the end of the application, release functions can be incorporated into the adhesive system. The adhesive strength is reduced upon the action of external triggers such as UV-irradiation, heat, the use of electric currents or magnetic fields. Thereby, debonding may follow various mechanisms, including phase changes, chemical reactions, crosslinking and volumetric expansion. Furthermore, electrostatic attraction, polarization, shape memory effects and mechanical adhesion can be employed. This review summarizes the most important properties of PSAs and provides an overview of well-proven as well as new approaches for "debonding-on-demand" adhesive systems. In addition, the article describes proposed and already implemented applications of the presented adhesive systems in the microelectronic industry, the automotive sector and the healthcare field.