Selective Infiltration in Polymer Hybrid Thin Films as a Gas-Encapsulation Layer for Stretchable Electronics

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Chemistry

Background:

• Developing effective gas barrier films is crucial for protecting sensitive materials in electronic devices.
• Traditional barrier films often face challenges with flexibility and long-term stability.
• Atomic Layer Infiltration (ALI) offers a novel approach to creating high-performance hybrid materials.

Purpose of the Study:

• To investigate the gas barrier properties of Al2O3-polymer hybrid layers created via ALI.
• To explore the relationship between infiltration depth and water vapor transmission rate (WVTR).
• To develop a stretchable gas-encapsulation film for advanced electronic applications.

Main Methods:

• Utilized the atomic layer infiltration (ALI) method to fill polymer free volumes with Al2O3.
• Prepared Al2O3-polymer hybrid thin layers using polyethylene terephthalate (PET), polyimide, and Nylon 6.
• Conducted Ca dot corrosion tests to evaluate WVTR.
• Demonstrated selective infiltration and developed a novel encapsulation strategy for stretchable films.

Main Results:

• Achieved extremely low WVTR values (<10^-6 g m^-2 day^-1) for Al2O3-PET, Al2O3-polyimide, and Al2O3-Nylon 6 hybrid films.
• Observed selective Al2O3 infiltration in PET over perfluoroalkoxy alkane (PFA), attributed to functional group anchoring.
• Developed a stretchable gas-encapsulation film with ultra-low WVTR (<10^-7 g m^-2 day^-1) even under stretching.

Conclusions:

• Al2O3-polymer hybrid films created by ALI exhibit excellent gas barrier properties.
• Selective infiltration is a key factor in optimizing hybrid film performance.
• These materials represent a highly promising hermetic sealing solution for stretchable, flexible, and foldable electronics.