Copper Nanoplates for Printing Flexible High-Temperature Conductors

Abstract

Copper has attracted immense interest in advanced electronics attributed to its abundance and high electrical and thermal characteristics. However, the ease of oxidation when subjected to heat and humidity drastically limits its material reliability under extreme environments. Here, we utilize copper nanoplates as a building block to achieve a thermally stable (upwards of 1300 °C), antioxidation, and anticorrosion-printed conductor, with the capability of additively manufacturing on Corning flexible Alumina Ribbon Ceramic. We elucidate the printed copper nanoplates with a low sheet resistance of 4 mΩ/sq/mil by means of a surfacecoordinated formate that inculcates high oxidation and corrosion resistance on a molecular level. In addition, an in situ copper− graphene conversion leads to a hybridized conductor displaying stability at elevated temperatures up to 1300 °C with high ampacity. Further mechanistic studies reveal high-temperature stability from in situ graphene conversion for copper and graphene interfaces, and preferential stacking of copper nanoplates, distinctly suited for emerging high-temperature flexible electronics.

Conformal Cu–CuNi Thermocouple Using Particle-Free Ink Materials

“…This was seen to a significantly lesser extent for CuNi, where the conductivity values were around 100 kS/m at all temperatures. The increased conductivity that is observed for Cu MOD can be explained with better percolation at increasing temperatures . However, the conductivity of CuNi was potentially affected due to the presence of the Ni phase.…”

“…As the other end of the thermocouple (the nonjunction end) is open, a contact electromotive force is produced, which is proportional to the temperature difference between the junction and nonjunction ends of the thermocouple. A transition to thin and compact thermocouples requires the use of printable inks with relatively lower energy needs . However, most printable metallic inks are prone to oxidation during storage and manufacturing. − A potential printable ink that addresses these challenges is the metal–organic decomposition (MOD) inks.…”

Copper inks for printed electronics: a review

“…Although the synthesis of copper particles with a smaller radius can effectively reduce the temperature required for sintering, 88,89 it will also make the particles agglomerate and precipitate in the solvent, 56 resulting in nozzle blockage during the printing process. At present, the mainstream solution to increase the interaction between molecules and cover the copper particles to form a protective layer is to add capping agents of organic substances, such as polyvinylpyrrolidone (PVP), 54,56,[90][91][92] oleic acid, 93 thiol, 94,95 oleamine, 96 cellulose 97,98 and acid. 76,99 The capping agents can be effectively desorbed during the subsequent sintering process, as shown in Fig.…”

“…Based on the excellent effect of formate, Sheng et al used iodine ions to control copper growth to obtain 2D morphological Cu nanoplates with (111) surface as the base. 97 The Cu nanoplates immersed in formate solution formed a dense passivation layer covered by formate on the Cu (111) surface after 12 h treatment at 120 °C. The passivated Cu-FA showed good stability at 350 °C and the resistance increased by only 10% after one day of immersion in 0.1 M NaOH solution (Fig.…”

Functionalized Gold Nanoparticles with a Cohesion Enhancer for Robust Flexible Electrodes

“…There is a strong demand for conductive inks to enable the additive manufacturing of a new generation of functional electronics, including printed and flexible electronics, wearable and healthcare electronics, and consumer electronics. − Various types of conductive inks have been developed, including those containing metals (e.g., silver, , gold, − copper, , and so forth), carbon allotropes (e.g., graphene, , CNT, , and so forth), and conductive polymers (e.g., PEDOT:PSS). , Of particular interest are conductive inks based on metal nanoparticles (NPs), which can be sintered at a lower temperature compared to that of the corresponding bulk metal due to the high surface area to volume ratio, and they exhibit relatively high electrical conductivities …”