University at Buffalo SUNY,
Keywords: printed electronics, high temperature, conformal
Summary:Each year, more than 60% of Cu is used in electrical applications due to its excellent electronic, thermal and mechanical properties. Here, we report printed Cu features (> 106 S/m) on dielectric substrates for flexible conformal electronics. The direct writing together with solvent exchange enables room-temperature printing of highly conductive Cu conductors without curing. We demonstrate radio-frequency antennas through all-printed Cu features on flexible ceramic material, in which we achieve a reflection coefficient of - 60 dB at the resonant frequency of 2.5 GHz. The stability of printed features is improved by Cu/Ni alloying which effectively protects it from oxidation. In addition, all high-temperature electronics printed onto flexible ceramics also exhibit high sensitivity (0.05% °C−1) and accuracy (15 °C) for temperature sensing between 25°C and 500°C, satisfying the real-time high-temperature monitoring. Our findings show that room temperature Cu conductors printed onto flexible dielectric substrates offer an opportunity to develop conformal high-temperature electronics, showing hybrid printability, conductivity without thermal treatment, as well as water-dispersibility, printable Cu ink provides new routes for manufacturing large-scale flexible hybrid electronics.