The current emphasis of crystal engineering, which has evolved over the past three decades through crystal packing analysis and identification of crystal design strategies, has shifted from structure to properties, i.e., design of molecular solids with targeted combination of properties. Amongst the panoply of chemical, physical, and biological properties that these materials exhibit, a comprehensive understanding of the mechanical properties is perhaps the most challenging as it involves connecting molecular level structural features to macroscopic mechanical behavior. However, the adoption of the nanoindentation technique, with which it is possible to measure—both quantitatively and accurately—the mechanical response of even small single crystals, in crystal engineering, has paved the way for substantial progress in the recent past. In this review, we summarize some recent results with an emphasis as to how one can design and control properties of molecular solids such as elastic modulus and hardness. This review closes with an enumeration of the key challenges that lie ahead. Such studies show a big scope for studying mechanical properties of organic crystals as a function of crystal structure, and in turn to understand their structure-property relationship for designing future smart materials. This emerging research field has prospects and a potential to play an important role in the future development of crystal engineering.

晶体工程的当前重点在过去的三十年中，通过晶体堆积分析和确定晶体设计策略而发展起来的，已经从结构转变为性能，即具有目标性能组合的分子固体设计。在这些材料所展现的化学，物理和生物学特性中，对机械性能的全面理解可能是最具挑战性的，因为它涉及将分子水平的结构特征与宏观机械行为联系起来。但是，采用纳米压痕技术可以定量地，精确地测量甚至小的单晶的机械响应，在晶体工程中，这为近来的实质性进展铺平了道路。在这篇评论中，我们总结了一些最近的结果，重点放在如何设计和控制分子固体的特性（如弹性模量和硬度）上。总结结束时，我们将对即将面临的主要挑战进行枚举。这些研究为研究有机晶体的机械性能随晶体结构的变化提供了广阔的空间，进而了解了它们在设计未来智能材料时的结构性质关系。这个新兴的研究领域具有前景，并有潜力在晶体工程的未来发展中发挥重要作用。这些研究为研究有机晶体的机械性能随晶体结构的变化提供了广阔的空间，进而了解了它们在设计未来智能材料时的结构性质关系。这个新兴的研究领域具有前景，并有潜力在晶体工程的未来发展中发挥重要作用。这些研究为研究有机晶体的机械性能随晶体结构的变化提供了广阔的空间，进而了解了它们在设计未来智能材料时的结构性质关系。这个新兴的研究领域具有前景，并有潜力在晶体工程的未来发展中发挥重要作用。