The paper presents a novel approach to enhance the stretchability of polymer semiconductors without compromising their charge transport mobility. The researchers developed a concept based on the nanoconfinement effect, where a conjugated polymer is phase-separated with a compatible elastomer (termed CONPHINE) to create a nanoscale semiconducting polymer network. This method significantly reduces the plastic modulus of the conjugated polymer, improving its stretchability while maintaining high mobility. The fabricated semiconducting film can be stretched up to 100% strain without affecting its mobility, achieving a record-high mobility of 1.32 cm²/Vs at 100% strain. The fully stretchable transistors exhibit high bi-axial stretchability and are demonstrated as a skin-like finger-wearable driver for an LED. The nanoconfinement approach is versatile and can be applied to various high-mobility conjugated polymers, making it a promising method for fabricating high-performance stretchable semiconductors.The paper presents a novel approach to enhance the stretchability of polymer semiconductors without compromising their charge transport mobility. The researchers developed a concept based on the nanoconfinement effect, where a conjugated polymer is phase-separated with a compatible elastomer (termed CONPHINE) to create a nanoscale semiconducting polymer network. This method significantly reduces the plastic modulus of the conjugated polymer, improving its stretchability while maintaining high mobility. The fabricated semiconducting film can be stretched up to 100% strain without affecting its mobility, achieving a record-high mobility of 1.32 cm²/Vs at 100% strain. The fully stretchable transistors exhibit high bi-axial stretchability and are demonstrated as a skin-like finger-wearable driver for an LED. The nanoconfinement approach is versatile and can be applied to various high-mobility conjugated polymers, making it a promising method for fabricating high-performance stretchable semiconductors.