Soft elasticity enabled adhesion enhancement of liquid crystal elastomers on rough surfaces

• 成果类型: Article
• 署名作者: Annapooranan, Raja; Yeerella, Ram Hemanth; Chambers, Robert J.; Li, Chenghai; Cai, Shengqiang
• 署名单位: University of California System; University of California San Diego; University of California System; University of California San Diego
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13424
• DOI: 10.1073/pnas.2412635121
• 发表日期: 2024-10-22
• 关键词: polydomain-monodomain transition; viscoelastic properties; contact mechanics; main-chain; tack; energy; time

摘要

The fabrication of pressure- sensitive adhesives (PSA) using liquid crystal elastomers (LCE) that are tolerant to substrate roughness is explored in this work. Traditional soft adhesives are designed by maintaining a balance between their cohesive strength and compliance. However, rough surfaces can significantly affect the adhesion strength of PSAs. Lowering the stiffness of the adhesive by reducing the cross- linking density or using additives can improve contact on rough surfaces. But this also decreases the cohesive strength and affects the overall performance of the adhesive. Additive- free LCE- based adhesives are shown to overcome these challenges due to their unique properties. Soft elasticity of LCE and low cross- link density contribute to their high compliance, while moderate cross- linking provides finite strength. The effect of contact time and substrate roughness on the adhesive performance is evaluated using probe- tack, indentation, lap shear, and static loading experiments. The unique combination of properties offered by LCE can lead to the development of roughness- tolerant adhesives, thereby broadening the application scope of PSAs.