The Role of Multi-Scale Porosity on Termite Mound Behavior

白蚁丘提供了一个很好的例子，自然建造的栖息地是有效和有弹性的。土堆建造是通过有效利用当地材料实现的，而不需要在开发人造材料时经常使用的热击处理循环。土丘也是自然界的结构和机械系统相结合的模型，仅通过结构的形式来提供通风和温度调节。对白蚁丘建造和功能所涉及的自然过程的了解可以适用于与建造人工结构相关的工程应用，这些人造结构需要零或最小的能量输入。此外，作为白蚁的微型3D打印土堆，这项工作可以为3D打印的人体结构提供新的范例。该跨学科项目将带来材料和结构形式的进步，这些材料和结构形式受到白蚁施工方法的启发，用于需要显著减少能源的结构，并且比传统建筑更可持续。研究成果将推动美国走向更大的能源独立和安全。新材料和新系统的技术转让将促进制造业发展，增强国民经济发展。该项目的总体目标是利用当地可获得的材料，为可持续的生物灵感建筑系统和生物胶结材料提供新的工艺信息。这将通过确定白蚁土丘的热和机械特性作为系统，以及生物胶结土壤的化学、热和机械特性，使用结构和材料的多尺度孔隙率作为关键参数来实现。白蚁丘复杂的纳米到巨型结构将使用一套先进技术进行分析。白蚁丘从宏观到超大规模的孔隙结构的3D模型将通过摄影测量绘制其外部地图，并通过对内部隧道结构的铸造模具切片进行成像来开发。采用氮气吸附、压汞孔隙率测定仪和高分辨率X射线微计算机断层扫描技术，对生物胶结材料的纳米到中观尺度的孔结构进行了测量。考虑到白蚁土丘的动态平衡，包括孔隙度，提供了材料特性在土丘通风、热和结构特征中的重要性的信息。通过研究白蚁通过结构拓扑和独特材料的协同作用来调节系统的能力，可以作为工程设计师高效和适应性地使用当地材料的起点。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Termite mounds provide an excellent example of naturally-built habitats that are efficient and resilient. Mound construction is achieved through efficient use of local materials without the need for a heat-beat-treat cycle often employed in the development of man-made materials. The mounds are also nature's model for combined structural and mechanical systems providing ventilation and temperature regulation solely through the form of the structure. An understanding of the natural processes involved in termite mound construction and function can be adapted to inform engineering applications related to the construction of man-made structures that require zero or minimal energy inputs. Also, as termites micro-3D-print mounds, this work can inform new paradigms in 3D-printed human structures. The transdisciplinary project will lead to advances in materials and structural forms that are informed by the construction methods of termites for structures that require significantly less energy and are more sustainable than traditional construction. Research outcomes will move the U.S. toward greater energy independence and security. Technology transfer of new materials and systems will grow manufacturing and strengthen national economic development. The overall goal of the project is to inform new processes for sustainable bio-inspired building systems and bio-cemented materials using locally available materials. This will be accomplished by identifying the thermal and mechanical properties of termite mounds as systems and the chemical, thermal and mechanical properties of the bio-cemented soil using the multi-scale porosity of the structure and material as the key parameter. The complex nano-to-mega-scale structure of the termite mounds will be analyzed using a suite of advanced techniques. 3D models of the macro-to-mega-scale pore structure of termite mounds will be developed by photogrammetric mapping their exterior and by imaging slices of cast molds of the interior tunnel structure. The nano-to-meso-scale pore structure of harvested bio-cemented material will be measured using nitrogen adsorption, mercury intrusion porosimetry, and high-resolution X-ray micro-computed tomography. Including porosity in consideration of homeostasis of termite mounds provides information on the importance of material properties in mound ventilation, thermal and structural characteristics. Studying the ability of termites to regulate systems through the synergy of the structural topology and unique materials can be a starting point for engineering designers to use local materials efficiently and adaptively.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.