Osmocapillary Adhesion: A Universal, Reversible, and Stimuli-Responsive Solution for Adhesion on Liquid-Contaminated and Low-Surface-Energy Substrates with Tunable Washability

This technology utilizes the osmocapillary effect in a swollen polymer network to generate adhesion. When the solvent is doped with surfactant, this technology enhances adhesion on surfaces contaminated with liquids such as water and silicone grease, as well as on low-surface-energy substrates such as Teflon and silicone. When a hydrophilic solvent is used, the adhesive is readily washable, allowing simple and quick label removal.

Description

The technology centers on an adhesive composition comprising a crosslinked polymer network swollen with a solvent to form a gel. Unlike traditional pressure-sensitive adhesives (PSAs) that rely on the polymer itself to wet a surface, this approach uses the solvent—often enhanced by the addition of a surfactant—to wet the substrate. Once wetting occurs, osmotic pressure within the liquid-filled interfacial gap acts to pull the gel and the substrate together, generating strong, reversible adhesion. The core innovation lies in the ability to use the liquid solvent to facilitate adhesion. A solvent modified by surfactant can simultaneously remove hydrophilic and hydrophobic interfacial contamination and wet both hydrophilic and hydrophobic substrates. If the solvent itself is hydrophilic, the adhesive can be easily removed by water. The interfacial solvent bridge is also fully reversible, allowing repeated adhesion even on highly contaminated substrates.

Applications

- Specialty Tapes and Films: High-performance adhesives for contaminated environments and low-surface-energy plastics.
- Washable labeling: Labeling on plastic containers that can be washed off before recycling.
- Medical and Wearable Devices: Adhesives capable of sticking to skin despite the presence of natural surface contaminants like sweat or oils.
- Electronics Manufacturing: Secure bonding for components on surfaces that are traditionally difficult to wet or contaminated with processing oils.
- Smart/Reversible Adhesives: Applications requiring switchable adhesion triggered by environmental changes such as temperature or humidity.
- Extreme Environment Adhesives: Versatile bonding solutions for environments where surface energy and contamination are persistent challenges.

Advantages

- Universal Adhesion: Provides robust bonding to diverse, low-surface-energy substrates (e.g., fluoropolymers) and surfaces with contaminants (e.g., oil, sweat).
- Highly Tunable: Allows for easy adjustment of wetting properties by modifying the solvent or surfactant without needing to change the base polymer synthesis.
- Stimuli-Responsive: The adhesion can be made switchable or responsive to external stimuli, such as temperature, humidity, or mechanical preload.
- Reversible: Consistent adhesion performance can be repeatedly achieved even on highly contaminated substrates.
- Versatile Design: Bulk properties can be optimized for enhanced energy dissipation, allowing for tailored adhesion energy (Γ).

Invention Readiness

The technology has been developed and validated at the laboratory scale using representative models, such as polyacrylamide-water systems. Experimental data have demonstrated that surfactant-assisted osmocapillary adhesion can achieve robust, substrate-independent strength that outperforms conventional PSAs on specific surfaces. Studies have also verified the ability to tune adhesion energy by modifying crosslinker-to-monomer ratios and entanglement density. Further studies are needed to optimize formulations for specific large-scale industrial applications and to conduct long-term durability and stability testing under real-world conditions.

IP Status

Patent Pending

Related Publication(s)

Shao, Z., Ji, R., & Liu, Q. (2026). Tree-frog-inspired osmocapillary adhesive reversibly bonds to diverse substrates. Extreme Mechanics Letters, 84, 102467. https://doi.org/10.1016/j.eml.2026.102467

Shao, Z., & Liu, Q. (2023). Osmocapillary adhesion: Reversible and strong adhesion between any hydrogel. Extreme Mechanics Letters, 61, 101996. https://doi.org/10.1016/j.eml.2023.101996