Metal-ion-tunable adhesive elastomers for mounting the multilayer elastic circuit

Multilayer elastic printed circuit boards (E-PCBs) have emerged as advanced configurations for integrating electronic components on elastomer substrates. However, weak inter-layer adhesion in elastic substrates can result in deformation-induced cracks and delamination in real-world applications. In this study, we present a novel approach to address this challenge by developing supramolecular sandwiched elastomers with high-adhesion skin and mechanically strong cores. This is achieved by precisely regulating the coordination bonds between different metal ions and the ethylenediamine groups within the aminated polydimethylsiloxane. The resulting sandwiched elastomer exhibits strong adhesion between layers (adhesion strength of 0.80 MPa), breaking strength of 0.81 MPa, Young’s modulus of 0.49 MPa, and maximum strain exceeding 500%. Leveraging these properties, the multilayered configuration of E-PCBs can be efficiently and securely assembled using the designed sandwiched elastomers through a simple layer-mounting method. This study offers a promising avenue for the simple and effective fabrication of mechanically stable multilayer flexible devices, eliminating the need for additional adhesive layers and complex structural constructions.