Linear Stiffness Tuning in MEMS Devices via Prestress Introduced by TiN Thin Films
Linear Stiffness Tuning in MEMS Devices via Prestress Introduced by TiN Thin Films
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DOI：
10.1021/acsaenm.3c00034
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发表时间：
2023-03
期刊：
影响因子：
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通讯作者：
Chao Zhuang;K. Minami;Kota Shiba;Genki Yoshikawa
中科院分区：
文献类型：
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作者：
Chao Zhuang;K. Minami;Kota Shiba;Genki Yoshikawa
刚度调整对于微/纳米级器件实现双稳性等高级功能至关重要，双稳性可以实现高效的能量收集、大运动驱动和可编程的机械性能。薄膜施加预应力是控制刚度的有效方法之一；但由于传统薄膜材料的可控性较差，在实际应用中很少使用。在这里，我们展示了通过在氮化钛（TiN）薄膜中使用预应力对微机电系统（MEMS）传感器进行鲁棒刚度调谐。受益于原子强化效应，TiN具有线性可控的预应力，可直接在机械装置中获得零刚度和负刚度，从而实现多种功能，包括在零刚度附近显著增强的灵敏度和当刚度变为负时的双稳态断裂行为。所展示的技术可以成为操纵机械行为的强大工具，并促进微/纳米级器件的特殊传感和驱动功能。
Stiffness tuning is crucial for micro/nanoscale devices to achieve advanced functionalities such as bistability, which enables efficient energy harvesting, large motion actuation, and programmable mechanical properties. Prestress implemented by thin films is one of the effective approaches for stiffness control; however, it is rarely used in practice because of the poor controllability in traditional thin film materials. Here, we demonstrate robust stiffness tuning on a microelectromechanical system (MEMS) sensor by using prestress in titanium nitride (TiN) thin films. Benefiting from the atomic peening effect, TiN exhibits linearly controllable prestress, which provides direct access to zero and negative stiffness in the mechanical device, resulting in multiple functionalities, including significantly enhanced sensitivity near zero-stiffness and bistable snapping behavior as stiffness becomes negative. The demonstrated technique can be a powerful tool to manipulate mechanical behaviors and facilitate exceptional sensing and actuating functionalities for micro/nanoscale devices.