Surface Non-Equilibrium State Induced by Unipolar Charge Collection for Constructing Constant Current Power Generation

The construction of stable and continuous output triboelectric nanogenerators (SC-TENGs) is of importance for the efficient utilization of ambient energy. Although structural optimization and material innovations have facilitated the diversified development of SC-TENGs, these devices based on the single-principle design still have limitations in energy harvesting efficiency. Here, a dual-channel SC-TENG is realized through the unipolar charge collection and the resulting surface non-equilibrium state. First, the air breakdown between the side electrode and the tribo-surface results in a constant current output. Second, the unipolar charge loss on the dielectric surface forms an unbalanced bias voltage, further polarizing the tribo-material and generating an induced constant current output. Based on the output consistency of bias polarization, the previously complex bottom electrode is replaced with a single electrode, greatly simplifying the manufacturing process. Besides, this structural significantly releases charge, resulting in a 325% increase in total charge output. This work unveils a novel mechanism for achieving constant current output through the construction of surface non-equilibrium states, paving a new pathway for SC-TENGs in high-efficiency energy conversion and multifunctional integrated applications.