Pulsed light sintering of silver nanoparticles for large deformation of printed stretchable electronics

Abstract

Growth of printed electronics has increased the interest in the nanoparticle inks. Research on flexible electronics has expanded not only due to inherent benefits of producing flexible products but also for its high-throughput manufacturability, such as roll-to-toll (R2R) process. Conventional sintering methods cause microcracks and voids in the sintered nanoink film, which lead to subpar performance, and are not suitable for the high-throughput R2R production. Furthermore, these methods are incompatible with many polymer substrates used in flexible electronics due to their low thermal budget. In this study, we present an alternative method utilizing an intense pulsed light (IPL) with a xenon flash lamp to sinter silver nanoink on a polymer substrate. The IPL method is capable of selectively sintering the silver nanoink in milliseconds without damaging the polymer substrates. The silver nanoink was stencil printed on a polydimethylsiloxane (PDMS) specimen. Samples were prepared using five different sintering conditions and tested under uniaxial strain. Three IPL sintering conditions were compared against a non-sintered (NS) and an oven-sintered (OS) conditions. The IPL-sintered samples show a significant improvement in tensile test over NS and OS samples. Samples sintered at 20 J/cm 2 of flash energy density and 10 ms of duration were stretched up to 27% strain before losing electrical conductivity. Scanning electron microscopy (SEM) confirms these results showing a reduction in porosity of the sintered nanoink as compared to NS and OS samples.

Flexible and Stretchable Bioelectronics

“…Printing of conductive liquid is mostly followed by the sintering process to create a conductive path. Sintering can be undertaken in several ways—self-sintering [ 108 ], mechanical [ 60 ], thermal [ 109 ], chemical [ 110 ], or using pulsed light [ 111 ] or a focused laser beam [ 105 , 112 ]. In addition to the robustness, flexibility, and stretchability of the device, printing also improves the repeatability and scalability of liquid metal processing and provides the capability of achieving electronics with complex patterns without compromising the electrical conductivity of the devices [ 60 ].…”

Nanomaterials for IoT Sensing Platforms and Point-of-Care Applications in South Korea

“…Subsequently, the GO sheets were reduced upon ultrafast optical irradiation by using IPL to form RGO (IPL-RGO) (Figure 5a). IPL irradiation is a facile method for generating heat in milliseconds without damaging the substrate [76]. After IPL irradiation, the electrical conductivity of the RGO sheets significantly increased as compared to that of the GO sheets.…”

Flashlight-Induced Strong Self-Adhesive Surface on a Nanowire-Impregnated Transparent Conductive Film

“…The flashlight annealing (FLA) process has received considerable attention as an advanced thermal process in the field of flexible and printed electronics because it allows electronic functional layers to be sintered, densified, and crystallized within a subsecond time range and simultaneously minimizes the thermal effect on the underlying heat-sensitive polymer substrate. In addition, this process is easy to implement over a large area and compatible with the roll-to-roll processes. − Consequently, various attempts have been made to utilize the FLA process for sintering metal nanoparticles (NPs) ,− or welding nanowires (NWs), ,,− curing oxide- or chalcogenide-based semiconductors, − and perovskite crystallization − for various electronic applications, such as displays, solar cells, and lightings.…”