Geometrically and Micromechanically Optimized Sprayable Short Fibers for Precision Pesticide Delivery.

Pesticides are crucial for global food security, but improving their efficient use to reduce environmental losses remains a key challenge for sustainable agriculture. One promising solution is enhancing pesticide adhesion to hydrophobic waxy leaf surface. Inspired by the dynamics of pinball machines, it is developed sprayable short-fiber carriers composed of biodegradable poly(3-hydroxybutyrate-4-hydroxybutyrate) using electrospinning technique and aminolysis. These suitable high-aspect-ratio fibers effectively anchored within gaps between rice leaf papillae, achieving 3.19-fold (Wilhelmy) and 1.47-fold (40°-spray) higher retention than spherical particles, along with 2.59-fold (fluorescence) and 1.43-fold (pesticide) improvements in anti-runoff performance. Finite element analysis showed that the fiber carrier enhanced contact area and frequency with papillae and achieved uniform strain distribution. The sprayable short-fiber suspension exhibited good stability, controlled release, antifungal activity against Botrytis cinerea and Rhizoctonia solani, and biosafety for zebrafish. Especially under simulated rain conditions, the antifungal efficacy against R. solani was significantly higher than that of a commercial suspension. By integrating geometric and micromechanical advantages, this innovative carrier advances precision pesticide delivery, addressing adhesion inefficiencies while reducing environmental losses to support sustainable crop protection.