Stretchable Serpentine Electrodes with High Fidelity Fabricated Using Orientation‐Controlled Surface Energy‐Directed Assembly

Abstract Stretchable serpentine electrodes have garnered significant attention in diverse fields such as embodied artificial intelligence, electronic skin, free‐form displays, stretchable integrated circuits, etc. However, current micro/nano fabrication processes often struggle with compatibility issues on stretchable substrates or face challenges related to scalability, fidelity, and resolution. Here, the study has developed an orientation‐controlled surface energy‐directed assembly (SEDA) process for fabricating high‐fidelity, high‐resolution serpentine electrodes with a linewidth of 600 nm. This process involves pulling out the serpentine patterns from nanomaterial suspensions in alignment with their axial orientation, ensuring that enclosed hydrophobic regions between the hydrophilic patterns and the three‐phase contact line (TPCL) do not form. Consequently, the TPCL can freely recede, facilitating high selectivity in assembly. In addition to orientation, the length‐to‐spacing ( L/S ) ratio of the serpentine pattern and the pulling speed also play crucial roles in determining the pattern fidelity. Specifically, at slow pulling speeds and low L/S ratios, the lateral receding time of the TPCL is shorter than its longitudinal receding time, leading to excellent assembly selectivity. To demonstrate the versatility of the orientation‐controlled SEDA process, serpentine electrodes are assembled from various nanomaterials, including silver nanoparticles, silver nanowires, carbon nanotubes, and liquid metal, on diverse substrates such as silicon, paper, polydimethylsiloxane, and thermoplastic polyurethane. The stretchable serpentine electrodes exhibit distinct strain‐resistive performance, and have been applied in various fields, including mechanical strain‐gated transistors, speech recognition micromotion sensors, interconnect circuits for light‐emitting diode displays, and human‐machine interaction gloves.