Mechanical metamaterials have introduced a paradigm shift in materials development by offering property control through geometrical design at the micro/mesoscale. The ensuing design flexibility has opened up avenues to leverage geometrical nonlinearities in the microstructure design to allow for realizing uncharacteristic global functionalities beyond the scope of traditional materials. In this work, we report on a class of programmable stiffness metastructures designed by patterning locally bistable dome units in structural element geometries. The global response characteristics of our metastructures reversibly switch between a plate-like response and a shell-like response as the bistable domes are switched locally between their two stable states. This allows for up to an order of magnitude variation in the global stiffness. Furthermore, we demonstrate the ability of our metastructures to enable in-situ property programmability in the presence of boundary conditions, thus paving the way for successful integration into larger structures. Uniquely, our architecture allows for multi-directional linear and nonlinear response programmability, while operating under different loading environments. As such, the presented designs can potentially serve as blueprint models to realize a new class of load-carrying, robust, programmable systems for soft robotics and morphing aerospace structures.

机械超材料通过在微观/中尺度上的几何设计提供属性控制，从而在材料开发中引入了范式转变。随之而来的设计灵活性为在微结构设计中利用几何非线性开辟了途径，以实现超出传统材料范围的非特征性全局功能。在这项工作中，我们报告了一类可编程的刚度元结构，这些结构是通过在结构单元几何中对局部双稳态圆顶单元进行构图而设计的。由于双稳态圆顶在其两个稳定状态之间局部切换，因此我们的元结构的整体响应特性可逆地在板状响应和壳状响应之间切换。这允许整体刚度的变化达到一个数量级。此外，我们展示了我们的元结构在存在边界条件的情况下实现原位属性可编程性的能力，从而为成功集成到更大的结构中铺平了道路。独特的是，我们的架构允许在不同的负载环境下运行时进行多向线性和非线性响应可编程性。这样，所提出的设计可以潜在地用作蓝图模型，以实现用于软机器人和变形航空航天结构的一类新型的承载，鲁棒，可编程系统。在不同的加载环境下运行时。这样，所提出的设计可以潜在地用作蓝图模型，以实现用于软机器人和变形航空航天结构的一类新型的承载，鲁棒，可编程系统。在不同的加载环境下运行时。这样，所提出的设计可以潜在地用作蓝图模型，以实现用于软机器人和变形航空航天结构的一类新型的承载，鲁棒，可编程系统。