Enhanced spontaneous self-charging through scalable template-free surface engineering at building block fiber scale for wearable electronics

Fiber/textile-based wearable electronics have been commercialized in recent years with high-tech functions, handy size, and light weight. Most of these wearable devices, however, can be re-charged only through an external electric connection. This feature has raised concerns for the implementation of wearable devices in advanced applications where standalone devices are needed. In spite of necessity of a self-charging capability, there have been limitations to implement the self-charging feature in wearable devices directly built on a bulk textile, falling into the dependence on the external energy source. In contrast, constructing wearables from their building block fibers that is a bottom-up device fabrication process provides an ideal solution to enable various functions, particularly the self-charging capability, for the advanced applications, such as bio-medical devices. To date, however, the bottom-up approach has faced several challenges due to its incompatibility with conventional methods and limited scalability at the building block scale. We introduce a viable route to achieve the self-charging capability of the building block fibers through a template-free scalable method. The fiber-based hybrid energy device, consisting of a supercapacitor and a triboelectric layer, exhibits enhanced electrochemical and spontaneous self-charging behaviors, attributed to dual effects of high plasma energy on both functional layers.