The Exoskeleton Barrier: Composition, Hydrophobicity, and Pathways for Penetration by Bio-Based Surfactants

Abstract
The insect exoskeleton represents one of the most remarkable natural engineering achievements, combining lightweight strength, structural rigidity, and exceptional hydrophobicity. Composed primarily of chitin, structural proteins, and an external lipid-rich wax layer, this multifunctional barrier protects the organism from physical injury, microbial invasion, and dehydration. Its molecular organization makes it extraordinarily resistant to water penetration and chemical disruption. In recent years, the rise of bio-based surfactants such as JC 9620 has introduced a sustainable pathway to modify these surfaces through physical–chemical rather than biochemical mechanisms. Biosurfactants act at interfaces—reducing surface tension, promoting micro-wetting, and enabling limited permeability across hydrophobic barriers. This review explores the molecular architecture of insect cuticles, the hydrophobic mechanisms that maintain their impermeability, and the potential of biosurfactants to temporarily alter these properties, resulting in moisture imbalance and behavioral dispersal. Analytical tools such as SEM, FTIR, and AFM are discussed as methods to visualize and quantify the interactions at the nano-to-micro scale. Understanding these mechanisms supports the design of environmentally responsible, non-toxic technologies for insect surface control, sanitation, and environmental hygiene.

Keywords: Insect cuticle, biosurfactant, JC 9620, hydrophobicity, surface tension, chitin, dehydration, dispersal, eco-compatible chemistry, surface modification