I-Corps: Auxetic Structures for Practical Applications

这个I-Corps项目的更广泛的影响/商业潜力在于为开发适用于广泛应用的增塑剂复合材料提供了一个框架（增塑剂材料在长度上拉伸时，在宽度方向上变厚，在纵向上压缩时变薄）。这个项目有可能成为研究、设计和制造增塑剂材料的关键。商业潜力跨越几个不同的行业，在这些行业中，人们寻求提高抗冲击性、抗压痕性、能量和吸声性能以及同碎屑曲率。最大的商业影响将是在需要这些性能组合的应用中，包括个人防护设备，以及汽车和航空航天领域的结构、噪音和振动应用。这个I-Corps项目的重点是开发负泊松比（即auxetic）复合材料，用于广泛的商业应用。该技术是由许多具有吸引力的机械性能的增氧材料的动机。理论上，负泊松比的材料比正泊松比的材料具有更高的硬度、抗冲击性、断裂韧性、吸声性能和剪切模量。此外，塑性材料在弯曲时表现出共裂曲率，这意味着它们可以弯曲成双重弯曲形状，从而消除了制造弯曲或圆顶形状零件所需的一些加工。由于目前大多数可用的增塑剂材料和结构都是多孔且刚度低的，因此实际的结构应用在很大程度上仍然难以捉摸。这个项目代表了一条直接的途径，即利用增氧材料的优势进行商业应用。该方法的独特之处在于使用折纸图案，这些折纸图案在折叠时表现出auxetic行为，从而为设计和开发一类新的负泊松比结构提供信息。这些结构可以通过折叠和/或增材制造来实现，根据具体应用选择材料和长度尺度。

The broader impact/commercial potential of this I-Corps project lies in the contribution of a framework for the development of auxetic composites that are suitable for a broad range of applications (an auxetic material, when stretched along its length, becomes thicker in width-wise directions and it becomes thinner when compressed lengthwise). This project has the potential to be pivotal in the way that auxetic materials are studied, designed and fabricated. The commercial potential spans several different industries where improved impact resistance, indentation resistance, energy and sound absorption properties, and synclastic curvature are sought. The greatest commercial impacts will be in applications requiring a combination of these properties, including personal protective equipment, and structural and noise and vibration applications in the automotive and aerospace sectors.This I-Corps project is centered on the development of negative Poisson's ratio (i.e. auxetic) composites for a wide range of commercial applications. The technology is motivated by the many attractive mechanical properties of auxetic materials. In theory, a negative Poisson's ratio material has improved hardness, impact resistance, fracture toughness, sound absorbing properties, and shear modulus over one with a positive Poissons ratio. In addition, auxetic materials exhibit synclastic curvature when bent, which means that they can be bent into a doubly curved shape, thus eliminating some of the machining necessary to fabricate curved or dome-shaped parts. Since most currently available auxetic materials and structures are porous and have low stiffness, practical structural applications remain largely elusive. This project represents a direct route to structures that exploit the benefits of auxetic materials for commercial applications. The uniqueness of the approach lies in the use of origami patterns which exhibit auxetic behavior when folded to inform the design and development of a new class of negative Poisson's ratio structures. Those structures can be realized through folding and/or additive manufacturing, with the material and length scale selection based on the specific application.