The study presents a durable Janus membrane with on-demand mode switching capabilities, fabricated using femtosecond laser microfabrication. The membrane features hydrophilic micropores and microgrooves (PG channels) that enable unidirectional water flow through the stretching Janus mode. In the protection mode, the PG channels close to resist external abrasion and impact, preserving the membrane's functionality under harsh conditions. The membrane demonstrates exceptional durability, maintaining water unidirectional penetration after 2000 cycles of mechanical abrasion and 10 days of air exposure. The protection mode enhances the membrane's robustness, allowing it to function as a fog collector in arid environments. The mode switching strategy significantly improves the mechanical durability of Janus membranes, opening new possibilities for applications such as multiphase separation, fog harvesting, and wearable health monitoring.The study presents a durable Janus membrane with on-demand mode switching capabilities, fabricated using femtosecond laser microfabrication. The membrane features hydrophilic micropores and microgrooves (PG channels) that enable unidirectional water flow through the stretching Janus mode. In the protection mode, the PG channels close to resist external abrasion and impact, preserving the membrane's functionality under harsh conditions. The membrane demonstrates exceptional durability, maintaining water unidirectional penetration after 2000 cycles of mechanical abrasion and 10 days of air exposure. The protection mode enhances the membrane's robustness, allowing it to function as a fog collector in arid environments. The mode switching strategy significantly improves the mechanical durability of Janus membranes, opening new possibilities for applications such as multiphase separation, fog harvesting, and wearable health monitoring.