Designing pores to suppressing crack generation at interface between serpentine interconnects and elastomers for highly-durable stretchable electronics

Serpentine interconnects enable rigid materials to have high stretchability. They are considered to be very effective architectures to enable stretchable electronics. Therefore, research has primarily focused on exploring serpentine-based designs to enhance the stretchability of the interconnect itself. However, in practical applications, the interfacial cracks caused by repetitive stretching becomes a critical issue if serpentine interconnects are encapsulated within a polymer matrix. Here, we introduce geometrically engineered pores in a polymer matrix to suppress interfacial cracks under stretching. The serpentine interconnects with optimized pores in a polymer matrix improved mechanical stability (strain at failure, fatigue life) and electrical stability compared with those without pores. Furthermore, these strategies enabled the demonstration of a stretchable light-emitting diodes (LED) array and an electrical heater.