Electroactive Carbon Regulated Electrodeposition Process of Copper and the Application in Liquid Metals Patterning for Flexible Electronics

The rapid progress and development of flexible electronic devices have made the traditional metal film preparation and patterning technologies increasingly insufficient to meet the processing requirements of various device forms. This study presents a method for fabricating liquid metal-based flexible circuits via controlled copper ion electrodeposition using nanocarbon black/graphene composite coatings. By systematically adjusting the ratio of nanocarbon black to graphene alongside electroplating voltage and time, we investigated the influence of active carbon coating composition on copper ion deposition kinetics and morphology. The deposition process was characterized in detail using in situ microscopy, an electrochemical workstation, scanning electron microscopy, X-ray diffraction, and contact angle measurements. Results demonstrate that the synergistic combination of graphene's superior electron transport properties with nanocarbon black's nucleation site functionality enables region-selective deposition with uniform nucleation density. The optimized composite coating achieved well-controlled patterned electrodeposition with enhanced selectivity and morphology uniformity. Finally, polymer-assisted transfer successfully produced functional EGaIn@Cu@PDMS flexible circuits, and the performance was validated in stretchable electronic devices. This work provides fundamental insights into interface-engineered electrodeposition while demonstrating a practical route for manufacturing flexible hybrid metal-polymer electronics.