Switchable adhesives, meaning the targeted switching off of adhesion, also known as "Debonding on Demand" (DoD), have been a long-cherished goal in the adhesive industry. The advantages of reversible bonding are clear: repair and recycling would be drastically simplified. This applies to complex technical constructions, such as replacing a smartphone display, as well as simpler joining parts for automobiles or packaging. Multiple reversibility and the associated self-healing of an adhesive bond can be seen as the ultimate goal, but even one-time switchability would provide significant added value for the majority of technical applications.
Unfortunately, there is an obvious conflict of interest. Adhesion must not fail during use in order to ensure, for example, stability against mechanical forces, chemical resistance, tolerance to temperature and humidity fluctuations, etc., but it should be easily detachable in repair or recycling cases. Despite numerous technological efforts, HENKEL and its competitors have not yet succeeded in combining the demanding criteria of a structural adhesive with satisfactory switchability for targeted debonding. A structural adhesive can be considered a "high-performance adhesive," as it is typically used for heavily stressed components. HENKEL is willing to take new paths, utilize biogenic resources, bring together competencies and scientists from various disciplines, and establish close, long-term cooperation with academia. The convergence of biotechnology, polymer chemistry, and engineering is explicitly seen as an opportunity to develop new biobased solutions. The work will focus on different material classes, with particular attention to electrochemical DoD.
