Laser-induced selective metallization of conductive patterns on silicone via copper carbonate hydroxide coating

Flexible electronics demand stretchable, high-performance interconnects for wearable and implantable applications. However, conventional methods such as direct-ink writing or doped-activator metallization face challenges including thermal degradation risks from high-temperature sintering, complex multi-step chemical procedures with toxic precursors. Here, we introduce an updated laser-induced selective metallization (LISM) for fabricating stretchable copper electrodes directly on a commercial polysiloxane rubber. This approach employs a spray-coated copper carbonate hydroxide activator, followed by near-infrared laser activating. Laser irradiation leads to the reduction of copper ions, along with the formation of amorphous carbon domains and micro-nanoscale surface structures. Electroless copper plating (ECP) and electroplating (EP) are subsequently performed to form continuous, low-resistivity serpentine traces. Comprehensive characterization verifies the successful reduction of copper and the robust integration of the electrode into the substrate. Mechanical testing shows that the structure maintains its electrical performance under repeated cyclic deformation. Functional demonstrations including electrocardiogram (ECG) patch, LED arrays, and wireless antennas showcase practical applicability of the proposed approach. Additionally, LISM operates at ambient temperature without toxic precursors and it minimizes chemical consumption and provides exceptional durability. This method advances next-generation electronics requiring both mechanical flexibility and electrical reliability. (Figure presented.)