Porcupine-Quill-Inspired Shape-Morphing Biointerfaces Disassemble Biofilms

Mature biofilms are difficult to eradicate because the extracellular polymeric substance (EPS) matrix shields embedded bacteria from chemical and mechanical attack. Here, we report a porcupine-spine-inspired photo-responsive dynamic offensive bio-interface that dismantles mature biofilms through electrically actuated mechanical penetration and light-driven oxidative stress. A high-aspect-ratio nano-dagger array undergoes reversible nanoscale deformation (∼110 nm) under an alternating electric field, while a photo-responsive heterostructure generates a surface photovoltage (∼364 mV) that enhances reactive oxygen species production. Mechanical penetration continuously disrupts the biofilm-surface interface, exposing bacteria within the EPS matrix to oxidative attack. This synergistic mechanism enables nearly complete biofilm eradication under complete immersion in bacterial suspensions of 10⁹ CFU mL^-1, outperforming representative state-of-the-art systems while maintaining stable antibiofilm activity for at least 10 days without chemical biocides. This work establishes a dynamic offensive strategy for durable self-cleaning and antifouling interfaces.