EAPSI: New insights into the effects of chemical composition and surface structure on spider silk adhesion and prey retention

附着力是施工和修复中的重要考虑因素。为了在地球上几乎所有的环境中生存，生物进化出了不同的黏合剂。在化学粘附中，化学键的形成和电子的共享在表面之间产生吸引力。例如，蜘蛛利用一种粘性的聚集体胶将猎物困在它们的网中。本项目将测试集料胶的粘合强度如何根据表面粗糙度、亲水性和化学成分而变化。在与东京大学的Tadashi Miyashita博士的合作下，他是之前唯一研究过Cytarachne蜘蛛丝的研究人员，这项研究将确定哪些表面特征作为进化压力，导致最佳的胶水粘附。对胶滴的化学成分进行鉴定。通过研究蜘蛛，它可以导致利用和模仿集料胶的化学化合物，导致基材特定的合成粘合剂产品。聚合丝由糖蛋白核心和盐的水滴组成。盐和糖蛋白的结合作用在丝线和猎物之间形成了一种纽带。Cyrtarachne属的蜘蛛是专门捕食飞蛾的圆织蜘蛛，只在亚洲发现，在日本更常见。这些蜘蛛已经进化到利用缩小的蛛网捕食飞蛾，蛛网上有异常大而粘稠的胶滴。成功捕获猎物主要依赖于胶水和外骨骼之间持久的粘附。不同的表面结构和化学成分可能会与糖蛋白和吸水盐发生不同的反应，从而导致cytarachne骨料胶的性能不足或过高。附着力测试将采用拉脱法进行。将获得关于它们含有什么化学物质以及它们何时最强的信息。NSF EAPSI奖是与日本科学促进会合作资助的。

Adhesion is an important consideration in construction and repair. Organisms have evolved different adhesives for survival in nearly every environment on earth. In chemical adhesion the formation of chemical bonds and sharing of electrons create attractive forces between surfaces. For example, spiders utilize a sticky aggregate glue to keep their prey ensnared in their webs. This project will test how adhesion strength of aggregate glue varies based on surface roughness, hydrophilicity, and chemical composition. In collaboration with Dr. Tadashi Miyashita at the Unversity of Tokyo - the only researcher to have previously studied the silk of the spider Cytarachne - the research will be determined which surface characteristics have served as evolutionary pressures, leading to optimal glue adhesion. Identification of the chemical composition of glue droplets will be conducted. By studying spiders, it can lead to the utilization and mimicking of aggregate glue chemical compounds leading to substrate specific synthetic adhesive products.Aggregate silk is composed of a glycoprotein core and an aqueous droplet of salts. The combination of salts and the glycoproteins act together to form a bond between the silk threads and prey. Spiders from the genus Cyrtarachne are specialized moth-hunting orb-weavers, only found within Asia and more commonly in Japan. These spiders have evolved to prey on moths by utilizing reduced orb webs with unusually large, viscous droplets of glue. Successful prey capture relies primarily on the prolonged adhesion between the glue and exoskeleton. Varying surface structures and chemical compositions may react with glycoproteins and hydroscopic salts differently resulting in scenarios in which Cyrtarachne aggregate glue under or over performs. Adhesion tests will be conducted by the pull-off method. Information will be gained on what chemicals they contain, and when they are strongest. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.