Preparation and properties of polyurethane/silicone materials for biomimetic gecko setae

摘要

In the biomimetic design of gecko setae, it is necessary to select materials with appropriate adhesive properties and to understand the effects of materials on normal and tangential adhesive forces. To meet the adhesion performance requirements of the biomimetic gecko robot foot, in this study, performance-improved polyurethane/silicone polymer materials were designed and synthesized, and the normal adhesion and tangential adhesion were measured using an adhesive friction comprehensive tester. The results show that normal adhesion increased with an increase in load when the normal load is small; when the normal load exceeds a critical value, the increase in normal adhesion slows and adhesion saturates. Under the condition of an adhesive state, the tangential adhesive force was larger for a smaller negative normal force, and a relatively large tangential adhesive force could be generated with a very small negative normal force. The elastic modulus of the synthetic polyurethane/silicone material varied with varying ratios of components, and it increased with increasing urethane content. Polyurethane/silicone material with about 30% polyurethane provided greater adhesion than other materials with different contents of polyurethane. The results provide a basis for the choice of biomimetic materials of the biomimetic gecko robot foot.