Molecular Rationale for the Design of Instantaneous, Strain-Tolerant Polymeric Adhesive in a Stretchable Underwater Human–Machine Interface

Strain-tolerant
reversible adhesion under harsh mechanical deformation
is important for realizing long-lasting polymeric adhesives. Despite
recent advances, cohesive failure within adhesives remains a critical
problem that must be solved to achieve adhesion that is robust against
humidity, heat, and mechanical stress. Here, we report a molecular
rationale for designing an instantaneous polymeric adhesive with high
strain tolerance (termed as iPASTE) even in a stretchable human–machine
interface. The iPASTE consists of two biocompatible and eco-friendly
polymers, linearly oligomerized green tea extracts, and poly­(ethylene
glycol) for densely assembled networks via dynamic
and reversible hydrogen bonds. Other than the typical approach containing
nanoclay or branched adhesive precursors, the linear configuration
and conformation of such polymer chains within iPASTE lead to strong
and moisture-resistant cohesion/adhesion. Based on the strain-tolerant
adhesion of iPASTE, it was demonstrated that a subaqueous interactive
human–machine interface integrated with a robot arm and a gold
nanomembrane strain-sensitive electronic skin can precisely capture
a slithery artificial fish by using finger gesture recognition.