The article presents the development of ultrathin and lightweight organic solar cells with high flexibility. The researchers demonstrate polymer-based photovoltaic devices on plastic foil substrates less than 2 μm thick, achieving power conversion efficiencies comparable to those of glass-based counterparts. These solar cells can withstand extreme mechanical deformation and have an unprecedented specific weight of 10 W g−1. The devices are fabricated using standard processing methods, making them suitable for applications such as electronic skin, textiles, and surface-conforming foils. The ultrathin nature of these solar cells, over ten times thinner and lighter than any other solar cell to date, makes them ideal for portable power solutions in various applications, including weather balloons, unmanned aircraft, and robotics. The study also highlights the mechanical resilience of the devices, showing that they can survive quasi-linear compression to below 70% of their original area and cyclic compression and stretching over 20 full cycles with minimal performance degradation.The article presents the development of ultrathin and lightweight organic solar cells with high flexibility. The researchers demonstrate polymer-based photovoltaic devices on plastic foil substrates less than 2 μm thick, achieving power conversion efficiencies comparable to those of glass-based counterparts. These solar cells can withstand extreme mechanical deformation and have an unprecedented specific weight of 10 W g−1. The devices are fabricated using standard processing methods, making them suitable for applications such as electronic skin, textiles, and surface-conforming foils. The ultrathin nature of these solar cells, over ten times thinner and lighter than any other solar cell to date, makes them ideal for portable power solutions in various applications, including weather balloons, unmanned aircraft, and robotics. The study also highlights the mechanical resilience of the devices, showing that they can survive quasi-linear compression to below 70% of their original area and cyclic compression and stretching over 20 full cycles with minimal performance degradation.