Abstract

We propose a moisture absorption and evaporation-enabled electricity generator (MAEG) inspired by the transpiration process of trees. The absorption layer of the MAEG is composed of a PSS@PVA hydrogel and a cotton fabric impregnated with lithium chloride (cotton@LiCl) to improve moisture absorption. The evaporation layer of the MAEG comprises a unidirectional moisture conduction Janus nanofiber membrane (UMCJ) that enhances water transportation and evaporation. Under ambient conditions, a single MAEG generates an open-circuit voltage (Voc) of 0.74 V and a short-circuit current (Isc) of 621.64 μA, maintaining a Voc of 0.75 V and an Isc of 61.54 μA after 50 days. The output performance of the MAEG exhibits minimal variation when bent from 0 to 180o. A maximum power density of 18.72 μW/cm2 is achieved with an external of 910 Ω. The scalability of the MAEG is impressive, with a series connection of 70 MAEGs yielding a Voc of 48.80 V, while a parallel connection of 70 units achieves an Isc of 45.77 mA. Notably, a series connection of three MAEGs can power an LED for over 5 days. Additionally, an array of 5x20, totaling 100 MAEGs, can directly charge a mobile phone without rectifier circuits or capacitors.