來源：
https://encyclopedia.thefreedictionary.com/auxetics
Auxetics are structures or materials that have a negative Poisson's ratio. When stretched, they become thicker perpendicular to the applied force. This occurs due to their particular internal structure and the way this deforms when the sample is uniaxially loaded. Auxetics can be single molecules, crystals, or a particular structure of macroscopic matter. Such materials and structures are expected to have mechanical properties such as high energy absorption and fracture resistance. Auxetics may be useful in applications such as body armor,[2] packing material, knee and elbow pads, robust shock absorbing material, and sponge mops.
輔助材料是具有負泊松比的結構或材料。拉伸時，在垂直於施加的力的方向上，它們變厚。這是由於它們特殊的內部結構和樣品單軸加載時的變形方式造成的。輔助物質可以是單分子、晶體或宏觀物質的特定結構。這種材料和結構有望具有高能量吸收和抗斷裂等力學性能。Auxetics可用於防彈衣、[2]包裝材料、護膝和護肘、堅固的減震材料和海綿拖把等應用。
The term auxetic derives from the Greek word αὐξητικός (auxetikos) which means "that which tends to increase" and has its root in the word αὔξησις, or auxesis, meaning "increase" (noun). This terminology was coined by Professor Ken Evans of the University of Exeter.[3]
auxetic一詞源於希臘語單詞αὐξητικός（auxetikos），意思是「傾向於增加的東西」，它的詞根是αὐξησις，或auxesis，意思是「增加」（名詞）。這個術語是由埃克塞特大學的肯·埃文斯教授發明的[3]。
The earliest published example of a synthetic auxetic material was in Science in 1987, entitled "Foam structures with a Negative Poisson's Ratio" [4] by R.S. Lakes from the University of Iowa. The use of the word auxetic to refer to this property probably began in 1991.[5]
最早發表的合成輔助材料的例子是1987年在《科學》雜誌上發表的，由愛荷華大學的R.s.Lakes撰寫，題為「具有負泊松比的泡沫結構」[4]。auxetic一詞用於指代這一領域可能始於1991年[5]。
Designs of composites with inverted hexagonal periodicity cell (auxetic hexagon), possessing negative Poisson ratios, were published in 1985.[6][7][8][9][10][11]
具有負泊松比的倒六邊形周期胞（auxetic hexagon）複合材料的設計於1985年發表。[6][7][8][9][10][11]
Typically, auxetic materials have low density, which is what allows the hinge-like areas of the auxetic microstructures to flex.[12]
通常，auxetic材料具有低密度，這使得auxetic微結構的鉸鏈狀區域能夠彎曲[12]。
At the macroscale, auxetic behaviour can be illustrated with an inelastic string wound around an elastic cord. When the ends of the structure are pulled apart, the inelastic string straightens while the elastic cord stretches and winds around it, increasing the structure's effective volume. Auxetic behaviour at the macroscale can also be employed for the development of products with enhanced characteristics such as superior footware based on the auxetic rotating triangles structures developed by Grima and Evans,[13][14] which is meant to enable an athlete’s natural motion and develop strength during running or training.
在宏觀尺度上，輔助行為（auxetic behaviour）可以用纏繞在彈性繩上的非彈性弦來說明。當結構的端部被拉開時，非彈性弦變直，而彈性繩在其周圍拉伸和纏繞，增加了結構的有效體積。宏觀尺度上的輔助行為也可用於開發具有增強特性的產品，例如基於Grima和Evans開發的輔助旋轉三角形結構的高級鞋具，[13][14]，其目的是使運動員在跑步或訓練期間能夠自然運動並發展力量。
https://encyclopedia.thefreedictionary.com/auxetics
"Hook's law". The Economist. 1 December 2012. Retrieved 1 March 2013.
Quinion, Michael (1996-11-09), Auxetic, retrieved 2009-01-02.
Lakes, R.S. (1987-02-27), "Foam structures with a negative Poisson's ratio", Science, 235 (4792): 1038–40, Bibcode:1987Sci...235.1038L, doi:10.1126/science.235.4792.1038, PMID 17782252.
Evans, Ken (1991), "Auxetic polymers: a new range of materials", Endeavour, 15: 170–174, doi:10.1016/0160-9327(91)90123-S.
Kolpakov, A.G. "Determination of the average characteristics of elastic frameworks". Journal of Applied Mathematics and Mechanics. 49 (6): 739–745. Bibcode:1985JApMM..49..739K. doi:10.1016/0021-8928(85)90011-5.
^ Almgren, R.F. (1985). "An isotropic three-dimensional structure with Poisson's ratio=-1". J. Elasticity. 15: 427–430. doi:10.1007/bf00042531.
Theocaris, P.S.; Stavroulakis, G.E.; Panagiotopoulos, P.D. (1997). "Negative Poisson's ratio in composites with star-shaped inclusions: a numerical homogenization approach .". Archive of Applied Mechanics. 67 (4): 274–286. Bibcode:1997AAM....67..274T. doi:10.1007/s004190050117.
Theocaris, P.S.; Stavroulakis, G.E. "The homogenization method for the study of variation of Poisson's ratio in fiber composites". Archive of Applied Mechanics. 69 (3-4): 281–295.
Stavroulakis, G.E. "Auxetic behaviour: Appearance and engineering applications". Physica Status Solidi (b). 242 (3): 710–720. Bibcode:2005PSSBR.242..710S. doi:10.1002/pssb.200460388.
Kaminakis, N.T.; Stavroulakis, G.E. "Topology optimization for compliant mechanisms, using evolutionary-hybrid algorithms and application to the design of auxetic materials". Composites Part B: Engineering. 43 (6): 2655–2668. doi:10.1016/j.compositesb.2012.03.018.
A stretch of the imagination - 7 June 1997 - New Scientist Space
Grima, JN; Evans, KE (2000). "Auxetic behavior from rotating squares". Journal of Materials Science Letters. 19: 1563–1565.
Grima, JN; Evans, KE (2006). "Auxetic behavior from rotating triangles". Journal of Materials Science. 41: 3193–3196.