Functionalized Gold Nanoparticles with a Cohesion Enhancer for Robust Flexible Electrodes

The development of conductive inks is required to enable additive manufacturing of electronic components and devices. A gold nanoparticle (AuNP) ink is of particular interest due to its high electrical conductivity, chemical stability, and biocompatibility. However, a printed AuNP film suffers from thermally induced microcracks and pores that lead to the poor integrity of a printed electronic component and electrical failure under external mechanical deformation, hence limiting its application for flexible electronics. Here, we employ a multifunctional thiol as a cohesion enhancer in the AuNP ink to prevent the formation of microcracks and pores by mediating the cohesion of AuNPs via strong interaction between the thiol groups and the gold surface. The inkjet-printed AuNP electrode exhibits an electrical conductivity of 3.0 x 10(6) S/m and stable electrical properties under repeated cycles (>1000) of mechanical deformation even for a single printed layer and in a salt-rich phosphate-buffered saline solution, offering exciting potential for applications in flexible and 3D electronics as well as in bioelectronics and healthcare devices.

Automated summary

To address the issue of microcracks and pores in printed gold nanoparticle films that lead to poor integrity and electrical failure, researchers have used a multifunctional thiol as a cohesion enhancer in the ink, preventing the formation of cracks and pores and improving the cohesion of the gold nanoparticles. The printed gold nanoparticle electrode exhibits stable electrical properties and conductivity even under mechanical deformation and in a salt-rich solution, showing potential for applications in flexible electronics, 3D electronics, bioelectronics, and healthcare devices.