The interfacial design of the electronic skins (E-skins), which are increasingly crucial in areas like exercise monitoring, healthcare, etc., has a great impact on wearability and functions. The adhesion between E-skin and human skin serves as the foundation for various functionalities. In addition to robust adhesion strength, detaching-on-demand, and waterproof abilities are also important for long-time wearing and comfort detachment after use. Here, self-adhesive, detach-on-demand, and waterproof hydrophobic E-skins (PBIA) by copolymerization of acrylates with conductive ionic liquid and adhesive components as the strain sensor and triboelectric nanogenerator (TENG) is developed. The strong van der Waals self-adhesion (shear adhesion of ≈574 kPa, peeling adhesion of ≈110 N m−1), and waterproof abilities under immersing, flushing, and penetrating situations enable the E-skin to realize stable and long-time monitoring for body motions in both the resistance sensing and TENG modes. Meanwhile, the easy detach-on-demand ability of van der Waals adhesion (574 to 35 kPa and 110 to 7 N m−1) guarantees the easy and comfortable detachment of PBIA after use, avoiding pain or injury to the skin. The adhesion strategy of PBIA can be expanded to other kinds of E-skins and accelerate the pace of practical applications of E-skins.