Dual Adaptation of a Flexible Shape Memory Polymer Adhesive.

A shape memory polymer (SMP) adhesive forms a conformal and hermetic contact with a target surface at the soft, rubbery state and provides a high-strength dry adhesion at the rigid, glassy state. In particular, recent SMP adhesive studies show SMP's ability to adhere to various rough and even underwater yet rigid surfaces. However, achieving and retaining the strong adhesion on flexible target surfaces such as common fabrics has not been reported since a flexible target surface would easily be peeled off from an SMP adhesive, which is too rigid to accommodate the target surface flexing. Here, we introduce the dual adaptation of an SMP adhesive composed of a thin SMP layer and a backing fabric, which involves the shape adaptation to make a strong adhesive contact and the flexure adaptation to tolerate a target surface flexing. To discover the criteria for optimizing both shape and flexure adaptations, we present the theoretical rationale as well as the computational and experimental studies in this work. Based on the findings here, we design a thin SMP adhesive and demonstrate its dry and underwater adhesive performances on common clothes to highlight its potential applications.