Skin-True Silicone Test Surfaces with Pinning-Engineered Chemistry and Topography

Overview

The offering is a family of silicone/PDMS test surfaces, or coupons, engineered to behave like human skin when interacting with complex aqueous fluids. Conventional silicone materials tend to shed fluids because of their low surface energy; these coupons address that by controlling contact-line pinning and wetting hysteresis at the surface. The result is a platform for reliably reproducing skin-like spreading, smearing, transfer, and friction behavior in controlled laboratory and product-development settings.

Potential applications include evaluation of skincare, cosmetic, and rinse-off formulations; consumer product testing; and other contexts where a durable, tunable skin surrogate is needed to assess fluid behavior or mechanical interaction. The surfaces are designed to provide repeatable metrics that can support formulation and product-development decisions.

Technical specifications

The design combines three surface-engineering approaches:

• Liquid-phase oxide infiltration of pre-extracted PDMS to create hydrophilic polymer-oxide hybrids, providing oxide-like interfacial behavior without polymer degradation or blooming.
• Patterned or gradient chemistries that control the density and location of pinning sites.
• Lithography-free laser micro/nanotexturing that tunes real contact area, targeting a coefficient of friction (COF) in the 0.4–0.6 range.

The design process is supported by a validated wetting model, open-source simulations, and physics-informed neural networks (PINNs) that predict static angles, hysteresis bounds, and durability behavior.

Characterization and validation:

• Topography metrics per ISO 25178, including Sq, Sdr, and Vvc.
• Surface chemistry via XPS, EDS, SEM/TEM, and ellipsometry.
• Advancing/receding contact angles and wetting hysteresis via force tensiometry.
• Performance metrics include initial and residual wetted area, roll-off, smear/transfer, and COF.
• Durability assessed through 5,000 rubs, 50 washes, and accelerated plus real-time aging up to six months.

Technology readiness level

The surfaces are at an early, active research and validation stage. The program is structured to progress from baseline characterization and design exploration through fabrication of 20–30 candidate designs, screening against pinning and friction targets, and durability optimization over a 12-month timeline. Deliverables include optimized coupons, validated fabrication and test protocols, and a documented scale-up path via molding. Because performance is application-dependent, users should expect to validate the surfaces against their own target fluids and protocols.