Laser-Based Fabrication of Carbon Nanotube–Silver Composites With Enhanced Fatigue Performance Onto a Flexible Substrate

Abstract

Flexible electronic devices involve electronic circuits fabricated onto a flexible (e.g., polymer) substrate, and they have many important applications. However, during their use, they often need to go through repeated deformations (such as bending). This may generate cracks in metallic components that often exist in a flexible electronic device and could obviously affect the device durability and reliability. Carbon nanotubes (CNTs) have a potential to enhance the metal fatigue properties. However, the previous work on the fabrication of CNT–metal composites onto a flexible substrate has been limited. This paper reports the research work on a novel laser-based approach to fabricate CNT–metal composites onto a flexible substrate, where mixtures containing CNTs and metal (silver) nanoparticles (NPs) are deposited onto the substrate through a dispensing device and then laser-sintered into CNT–metal composites. Under the studied conditions and for the tested samples, it has been found that overall the addition of CNTs has significantly enhanced the bending fatigue properties of the laser-sintered material without degrading the material electrical conductivity (which has actually been slightly increased). The laser-based approach has several potential advantages, such as the local, precise, and flexible production of CNT–metal composite patterns with small or little thermal effects to the flexible substrate and other surrounding regions, and without using a mask or vacuum. Future work is certainly still needed on this novel fabrication process.