Glaser Niels C, Langowski Julian K A
Department of BioMechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
Experimental Zoology Group, Department of Animal Sciences, Wageningen University and Research, De Elst 1, 6708 WD Wageningen, The Netherlands.
R Soc Open Sci. 2023 Mar 8;10(3):221263. doi: 10.1098/rsos.221263. eCollection 2023 Mar.
Biomimetic adhesives with a stiff fibre-reinforced base layer generate strong attachment, even without bioinspired micropatterning of the contact surface. However, current fibre-reinforced adhesive designs are still less versatile with respect to substrate variability than their biological counterparts. In this study, we enhance the comformability of a fibre-reinforced adhesive on curved substrates by adding bioinspired soft backings. We designed and fabricated soft backing variations (polyurethane foams and silicone hydroskeletons) with varying compressive stiffnesses that mimic the soft viscoelastic structures in the adhesive appendages of tree frogs, geckos and other animals. The backings were mounted on a smooth silicone layer enforced with a polyester mesh, and we experimentally investigated the contact area and friction performance of these adhesives on a curved substrate. The results show that the contact area and friction created by a fibre-reinforced adhesive with a soft backing in contact with a non-flat substrate scale inversely with backing stiffness. The integration of stiff fibre-reinforcement with a compressible backing represents an important step in bringing bioinspired adhesives out of the laboratory and into the real world, for example in soft robotic grippers. Moreover, our findings stimulate further research into the role of soft tissues in biological adhesive systems.
具有坚硬纤维增强基层的仿生粘合剂即使在接触表面没有仿生微图案的情况下也能产生强大的附着力。然而，目前的纤维增强粘合剂设计在适应不同基材方面仍不如其生物同类产品灵活。在本研究中，我们通过添加仿生软衬来提高纤维增强粘合剂在弯曲基材上的贴合性。我们设计并制造了具有不同压缩刚度的软衬变体（聚氨酯泡沫和硅酮水骨架），以模仿树蛙、壁虎和其他动物粘性附肢中的软粘弹性结构。这些衬垫安装在由聚酯网加强的光滑硅酮层上，我们通过实验研究了这些粘合剂在弯曲基材上的接触面积和摩擦性能。结果表明，带有软衬的纤维增强粘合剂与非平面基材接触时产生的接触面积和摩擦力与衬垫刚度成反比。将坚硬的纤维增强材料与可压缩衬垫相结合，是使仿生粘合剂走出实验室并应用于现实世界（例如软机器人夹具）的重要一步。此外，我们的研究结果激发了对软组织在生物粘合剂系统中作用的进一步研究。
