仿生黏附材料的黏附性能评价及初步应用探索

Adhesion Property and Primary Application Exploration of Bio-inspired Adhesive

针对空间微重力条件下固体间稳定黏附的技术需求,基于范德华力黏附作用机制的仿生黏附材料有望在空间环境中展现稳定黏附性能。通过模板法和化学气相沉积法制备出具有仿壁虎刚毛纤维阵列结构的聚乙烯基硅氧烷(PVS)高分子聚合物及垂直定向排列碳纳米管阵列(VACNT)仿生黏附材料,再由扫描电子显微镜、黏附-脱附行为测试平台对仿生黏附材料的微观结构及黏附行为进行了测试,并对种子、粮食颗粒及常用零部件的黏附固定效果进行了初步考察。结果表明,仿生黏附材料具有微纳米级刚毛结构。PVS具有稳定的可重复黏附特性,其法向黏附性能优于切向黏附性能,与蘑菇状顶端在黏附中发挥主要作用有关。而VACNT具有稳定的切向可重复黏附特性,其切向黏附性能优于法向黏附性能,是由VACNT黏附主要依靠侧面接触决定。VACNT和PVS对不同品种的生菜种子和粮食颗粒均能产生有效黏附固定,PVS还能够对空间站常用到的零部件进行稳定固定。

Bio-inspired adhesive technology based on Van der Waals forces can be used to realize stable adhesion in the space microgravity environment. In this study, two different kinds of bio- in-spired adhesives （carbon nanotube array （VACNT） and polyvinylsiloxane （PVS）） with gecko hairs-mimetic structure were prepared by template method and chemical vapor deposition method. The structure and adhesion behavior of bioinspired adhesive were examined with SEM and the multi-functional material adhesion test platform. In addition, the fixation abilities to lettuce seeds,grain particles and the small tools were also evaluated. The results showed that both bio-inspired adhesives had micro-nano scale gecko-mimic array structure. The normal adhesion strength of PVS was higher than the shear adhesion strength due to the mushroom-tips effect during adhesion, whereas both of them was repeatable and stable. The shear adhesion strength of VACNT was higher and more stable than the normal adhesion strength, which was affected by the side-wall contact of carbon nanotubes.Both VACNT and PVS adhesive could effectively fix the lettuce seeds and grain particles, and PVS combined with gloves could fix the small components and pick up the small tools very well in the ground environment.