Durable skin-mimetic silicone surface for controlled wetting, transfer, and friction

Overview

Silicone materials such as PDMS naturally repel water-containing fluids and have low, non-skin-like friction, making it difficult for fluids to spread, pin, smear, or transfer in the way silicone can be used in contact with skin. This proposal describes a durable skin-mimetic silicone surface that combines two design levers to overcome these limitations: a controlled microtexture and a thin, covalently grafted hydrophilic polymer layer.

The grafted polymer chemistry tunes the surface polarity and its contact-angle hysteresis, enabling wetting, spreading, pinning, smearing, and transfer rather than the roll-off and dewetting usually seen with ordinary silicone. The microtexture adds a separate and independent parameter for controlling fluid retention and friction, allowing the surface to be adjusted toward a target coefficient of friction of 0.4–0.6, which is more characteristic of skin.

Because the hydrophilic chemistry is covalently attached, it is designed to prevent the polymer and finish from washing out, and the surface is intended to stay performance-oriented through repeated rubbing, cleaning, and storage.

Technical Specifications

The surface is being developed as a PDMS-based material with the following key features:

• Two tunable parameters: controlled microtexture and covalent graft composition/density.
• A hydrophilic polymer layer that tailors surface polarity, spreading, pinning, and transfer behavior.
• Surface texture tuned toward fluid retention and friction using 3D roughness parameters including Sq, Sdr, and Vvc.
• Target coefficient of friction of 0.4–0.6.
• Covalent attachment for resistance to leaching, rubbing, washing, and aged storage.
• Validation and characterization of wetting, hysteresis, roll-off, transfer, friction, and surface topography.

Technology Readiness Level

This is an early-stage research technology at the design and hypothesis-condition phase. Planned validation includes Phase 1 fabrication of a PDMS coupon design matrix with untreated controls; Phase 2 screening of advancing and receding contact angles, hysteresis, residual fluid area, tilt/roll-off, smear/transfer, and coefficient of friction; and Phase 3 durability testing under accelerated storage, repeated movement/rubbing, and standardized washing/cleaning.

At this stage, the surface has not yet been commercialized. It is presented as a development-ready research solution for parties interested in co-developing this skin-mimetic silicone technology and advancing it toward real-world product integration.