Fully printed planar moisture-enabled electric generator arrays for scalable function integration

Ubiquitous moisture is of particular attraction for sustainable power generation. However, rigorous assembly procedures limit the efficient large-scale integration for moisture-enabled electric generators (MEGs). Herein, we develop fully printed planar MEG (PMEG) arrays using modulated polycation and polyanion inks, which maximize access to moisture and make it free of strict assembly and device packaging. Thus, a PMEG unit (only 0.3 cm 2 ) generates an open-circuit voltage of up to 1.1 V, along with a power density of 2.6 μW cm −2 . A small piece of sheet with 200 PMEG units offers a maximum voltage of 200 V and a current of 1.3 mA. A standard power module is constructed to meet the on-demand power supply requirements of compact electronics. Furthermore, scalable and customizable PMEG arrays can be compatibly integrated with flexible circuits, as demonstrated by a fully printed self-powered functional system including PMEG arrays and energy-storage and electrochromic devices.