Piezoelectric microsystems are of use in areas such as mechanical sensing, energy conversion and robotics. The systems typically have a planar structure, but transforming them into complex three-dimensional (3D) frameworks could enhance and extend their various modes of operation. Here, we report a controlled, nonlinear buckling process to convert lithographically defined two-dimensional patterns of electrodes and thin films of piezoelectric polymers into sophisticated 3D piezoelectric microsystems. To illustrate the engineering versatility of the approach, we create more than twenty different 3D geometries. With these structures, we then demonstrate applications in energy harvesting with tailored mechanical properties and root-mean-square voltages ranging from 2 mV to 790 mV, in multifunctional sensors for robotic prosthetic interfaces with improved responsivity (for example, anisotropic responses and sensitivity of 60 mV N⁻¹ for normal force), and in bio-integrated devices with in vivo operational capabilities. The 3D geometries, especially those with ultralow stiffnesses or asymmetric layouts, yield unique mechanical attributes and levels of functionality that would be difficult or impossible to achieve with conventional two-dimensional designs.

压电微系统可用于机械感测，能量转换和机器人技术等领域。这些系统通常具有平面结构，但是将其转换为复杂的三维（3D）框架可以增强和扩展其各种操作模式。在这里，我们报告了一种受控的非线性屈曲过程，可将光刻定义的二维图案的电极和压电聚合物薄膜转换为复杂的3D压电微系统。为了说明该方法的工程通用性，我们创建了二十多种不同的3D几何形状。然后，借助这些结构，我们将展示量身定制的机械性能和均方根电压范围从2 mV至790 mV的能量收集应用，^-1（法向力），并且在具有体内操作能力的生物集成设备中使用。3D几何形状，尤其是具有超低刚度或不对称布局的3D几何形状，具有独特的机械属性和功能级别，而传统的二维设计则很难或无法实现。