Firoozy Peyman, Seifnejad Haghighi Milad, Kanygin Mikhail, Ferguson Philip, Bahreyni Behraad
School of Mechatronic Systems Engineering, Simon Fraser University, Surrey, BC, V3T 0A3, Canada.
Department of Mechanical Engineering, University of Manitoba, Winnipeg, MB, R3T 5V6, Canada.
Microsyst Nanoeng. 2025 Oct 24;11(1):196. doi: 10.1038/s41378-025-01066-3.
The small dimensions of microfabricated devices present challenges in applications such as inertial sensing, where a larger proofmass is necessary for enhanced sensitivity. An effective approach to addressing the limitations of linear sensing is to use nonlinear mechanisms that adapt the device's response according to different operating conditions. This paper introduces a new nonlinear spring mechanism for use in microsensors that harnesses the buckling phenomenon to achieve stiffness softening. The proposed mechanism utilizes a micro-arm to apply an eccentric axial load to an inclined beam, causing it to buckle in a controlled manner under a specified load. Once buckled, linear springs dominate the response of the system. We demonstrate that this method results in a smaller bias displacement compared to previously reported techniques based on snap-through behaviour, leading to potential reductions in device size and improvements in operational range. The behaviour is analytically modelled and verified through simulations. A prototype device was designed and microfabricated to experimentally validate the design principles. Compared to pre-curved nonlinear springs, the proposed design results in an 11-fold reduction in bias force, a 100-fold reduction in bias displacement, and a reduction in mechanical stiffness by a factor of 520. These results were verified through experiments conducted on a microfabricated accelerometer with an on-chip optical interferometer. Test results reveal an extended linear range of better than , a bias force of 0.3 , and a bias displacement of 10 , measured with an integrated optical interferometer with a displacement noise floor of 40 at 2 and sensitivity of .
微纳制造设备的小尺寸在诸如惯性传感等应用中带来了挑战，在惯性传感中，为了提高灵敏度需要更大的质量块。解决线性传感局限性的一种有效方法是使用非线性机制，该机制可根据不同的操作条件调整设备的响应。本文介绍了一种用于微传感器的新型非线性弹簧机制，该机制利用屈曲现象实现刚度软化。所提出的机制利用微臂向倾斜梁施加偏心轴向载荷，使其在指定载荷下以可控方式屈曲。一旦屈曲，线性弹簧将主导系统的响应。我们证明，与先前报道的基于快速通过行为的技术相比，该方法导致的偏置位移更小，从而有可能减小设备尺寸并扩大工作范围。通过模拟对该行为进行了分析建模和验证。设计并微纳制造了一个原型设备，以通过实验验证设计原理。与预弯曲的非线性弹簧相比，所提出的设计使偏置力降低了11倍，偏置位移降低了100倍，机械刚度降低了520倍。通过在带有片上光学干涉仪的微纳制造加速度计上进行的实验验证了这些结果。测试结果显示，线性范围扩展到优于 ，偏置力为0.3 ，偏置位移为10 ，这是使用集成光学干涉仪在2 时测量的，位移本底噪声为40 ，灵敏度为 。
