INIDS2-1671
Wrinkle-Induced Marangoni Flow Enables Dynamic Homogenization of Inorganic UV Filters in Sunscreen Films
Topic
IDS2. Frontiers in Cosmetic Science and Technology (Sponsored by COSMAX)
When and Where
Sep 29, 2026
11:40 - 12:05
Room 102
Session Chairs
Hyosung AN
Presenter(s)
Jun Dong Park (Sookmyung Women's University)
Co-Author(s)
Abstract
Uniform deposition of inorganic UV-filter particles on the skin is critical for maximizing photoprotective performance while minimizing visible whitening. However, the skin's intrinsic microtopography hinders even coverage by trapping UV-filter particles within surface furrows, which reduces spatial uniformity and causes a white cast. Here, we present a sunscreen design strategy that addresses these wrinkle-induced limitations through dynamic homogenization driven by skin-wrinkle-induced Marangoni flow. Specifically, two solvents with different volatilities and surface tensions were combined to generate a surface-tension gradient arising from curvature-dependent differences in evaporation rate between skin ridges and furrows. This gradient induced interfacial flow that extracted UV-filter particles trapped within furrows and redistributed them more uniformly across the skin surface. Microscopic analyses using confocal and optical microscopy on skin-mimetic substrates confirmed significantly improved uniformity of particle deposition. This enhanced spatial homogeneity simultaneously led to improved UV-blocking performance and suppressed white cast. By exploiting, rather than circumventing, the wrinkle structure of skin as a functional driver of interfacial transport, this work provides a new design principle for inorganic sunscreens that integrates improved photoprotection with enhanced cosmetic acceptability.
