Ultrathin Cellulose Ionogel Devices Through Solvent‐Induced Peeling

Abstract Ultrathin devices represent a significant advancement in materials science and technology, playing a crucial role in wearable electronics, smart healthcare, and human‐computer interaction. However, achieving mechanical durability, interface stability, and performance trade‐offs remains challenging. Herein, the study reports a scalable layer‐by‐layer exfoliation strategy for the rapid and patterned fabrication of ultrathin cellulose ionogel devices, employing a solvent‐induced assembly of cellulose molecules and active substances. The resulting freestanding devices, with a thickness of 12.46 µm—approximately one‐ninth the thickness of human hair, exhibited desirable mechanical tensile strength (6.5 MPa), high pressure sensitivity (75.82 kPa ⁻¹ ), low impedance characteristics (5.83 Ω at 1 kHz), and outstanding interfacial stability, as evidenced by the ability to endure 500 cycles of tape stripping. Furthermore, due to effective self‐healing and controllable induced peeling characteristics, the study is able to conduct the patterned fabrication of various ultrathin devices without the limitation of active materials. This peeling strategy based on sustainable resources offers a valuable solution for designing and optimizing ultrathin electronic devices without requiring substantial time or cumbersome processing.