A Scalable Double-Sided Wet Etching Strategy for Large-Area Mushroom-Shaped Bionic Adhesives.

Mushroom-shaped tip architectures play a central role in enhancing the performance of bionic adhesives by amplifying adhesion strength through optimized stress distribution and increased interfacial contact. However, current approaches for fabricating molds of complex adhesive structures are often constrained by high cost, limited repeatability, and limited ability to fabricate complex 3D geometries. These challenges highlight a critical need for high-strength 3D metal molds that support the scalable manufacturing of mushroom-shaped adhesive architectures. Here, this work introduces a scalable manufacturing route using coordinated double-sided non-simultaneous wet etching. This approach enables precise morphological control and large‑area fabrication of mushroom‑shaped microstructures in a one-step subtractive process within tens of minutes. By regulating the etching time and mask dimensions, key geometrical parameters, including the necking position and taper angle, can be accurately and reproducibly tuned. The replicated Adhesive structures exhibit high adhesion strength of up to 17.37  N cm