Epidermal electronics are extensively used in human-machine interfaces and wearable sensors. However, managing sweat and gas permeability at the skin-device interface to ensure comfort and prevent skin damage during prolonged use remains a key challenge. Inspired by the fog collection mechanism of cactus spines and trichomes, this work develops a biomimetic, flexible epidermal electronic device with high gas permeability and unidirectional water transport capability. The device exhibits excellent flexibility (Young's modulus: 0.02 MPa), breathability (electrode: 3551.63 g day