Biomaterials For Small Tools

非技术性：该奖项由材料研究部的生物材料计划授予俄勒冈大学尤金分校，旨在研究小型生物为应对整体工具以及超微结构和分子尺度上的缩放规则而进化的机械和材料适应性。当农民的收割工具变得迟钝时，可以磨利或更换。然而，这些选项对许多动物来说是不可用的。他们必须依赖那些每次使用都注定会变得效率低下的工具。对于蜘蛛和昆虫这样的小动物来说，这尤其有问题，它们依靠工具的锋利来克服与其大小相关的力量限制。许多小动物的牙齿、下巴、爪子和刀片中含有高达25%的锌、铁、铜、锰、碘和溴，这种奇怪的材料可能是进化出来的，通过减少磨损和骨折来应对这一挑战。本项目将研究这些材料的性能，并详细调查它们的组成。从这些在小生物体中进化的材料中可以学到新的理解，以应对与小规模机械相互作用相关的独特挑战。此外，类似材料还可应用于医疗器械(如手术刀和微型“机器人”)、原子力显微镜尖端等锋利工具，或其他需要坚硬但耐冲击材料的应用。该项目将为研究教育提供巨大的机会，因为它是如此跨学科，结合了材料科学、生物学、化学和物理的方法。这项研究将与这一跨学科领域的研究生和本科生的教学和培训相结合。技术：更锋利的工具使较小的动物(以及小型、力量有限的机器)能够切割和穿透与它们更大、更结实的同类动物相同的材料。蚊子和狮子都刺穿同一个皮肤，树懒和切叶蚂蚁必须都割同样的叶子。但随着工具半径变小，打破工具所需的能量变得比用工具刺穿薄膜所需的能量更小、更快，从而增加了破裂的可能性。提出者将研究在小型生物体中进化的机械和材料适应，以应对整个工具、超微结构和分子尺度上的这种缩放规则。拟议的活动将：1)第一次测试用于小动物机械结构的几种重元素生物材料(HeBS)的机械性能；2)测试一种新的标度规则，该规则表明较小的动物需要更多的抗骨折工具；3)开始测试新的假设，即重原子可以被用来降低分子共振频率，从而抑制冲击产生的高频振动；4)测试水结合的变化与HeBS中硬度和抗断性的平衡相关的假设；5)测试机械性能平衡的预测，特别是HeBS，基于它们在生物工具中的位置；以及6)检验特定的锌结合假说。该奖项的研究人员将使用他们已经开发或将开发的工具来测量小样本的机械性能，以及先进的化学技术，如原子探针断层扫描。该项目将提供这些尖端技术方面的研究培训，并获得跨学科研究方面的专门知识。代表不足和非传统的学生将积极招募和指导，并将通过当地社区大学的实习计划提供参与这项研究的机会。研究生和本科生将在根据本项目成果开发的课程中接受研究培训。

Nontechnical: This award by the Biomaterials Program in the Division of Materials Research to University of Oregon Eugene is to study the mechanical and material adaptations that have evolved in small organisms to cope with the scaling rule on the whole-tool, and at ultrastructural and molecular scales. When a farmer's harvesting tools get dull, they can be sharpened or replaced. However, these options are not available to many animals. They must rely on tools that are doomed to become less efficient with each use. This is especially problematic for small animals like spiders and insects that rely on the sharpness of their tools to overcome the force limitations associated with their size. It may be that the strange materials, containing up to 25% of zinc, iron, copper, manganese, iodine and bromine that are found in the teeth, jaws, claws and blades of many small animals have evolved to meet this challenge by reducing wear and fracture. This project will study the properties of these materials, with a detailed investigation of their composition. New understanding may be learned from these materials that have evolved in small organisms to meet their distinctive challenges associated with small-scale mechanical interactions. Furthermore, similar materials may find application in sharp tools such as medical devices (e.g. scalpels and miniature "robots"), atomic force microscopy tips, or in other applications that require hard but impact resistant materials. The project will provide great opportunities for research education because it is so interdisciplinary, combining methods from material science, biology, chemistry and physics. This research will be integrated with teaching and training graduate and undergraduate students in this interdisciplinary area.Technical: Sharper tools enable smaller animals (and small, force-limited machines) to cut and puncture the same materials as their larger and stronger counterparts. A mosquito and a lion both puncture the same skin, a sloth and a leaf cutter ant must both cut the same leaves. But as the tool radius gets smaller, the energy required to fracture the tool gets smaller and faster than the energy required to puncture the membrane with the tool, making fracture increasingly likely. The proposers will study the mechanical and material adaptations that have evolved in small organisms to cope with this scaling rule on the whole-tool, ultrastructural, and molecular scales. The proposed activity will: 1) test, for the first time, the mechanical properties of several Heavy Element Biomaterials (HEBs) used in mechanical structure in small animals; 2) test a novel scaling rule suggesting that smaller animals need more fracture resistant tools; 3) begin to test the novel hypothesis that heavy atoms can be used to lower molecular resonant frequencies and thereby damp the high frequency vibrations from impact; 4) test the hypothesis that variations in water binding are correlated with the balances of hardness and fracture resistance in HEBs; 5) test predictions of the balance of mechanical properties in particular HEBs, based on their locations in biological tools; and 6) test a specific zinc binding hypothesis. The researchers of this award will use tools that they have developed or will be developing for measuring mechanical properties of small specimens, as well as advanced chemical techniques such as Atom Probe Tomography. This project will provide research training in these cutting edge technologies as well as gain expertise in interdisciplinary research. Underrepresented and nontraditional students will actively recruited and mentored, and will provide opportunities to participate in this research through an internship program with a local community college. Graduate and undergraduate students will receive research training in a course developed from the outcome of this project.