GA, UNITED STATES, February 20, 2026 /EINPresswire.com/ — Achieving both high sensitivity and a wide dynamic range remains a central challenge in microelectromechanical accelerometers. This study presents a newly engineered nonlinear stiffness-softening mechanism that enables micro-electro-mechanical systems (MEMS) accelerometers to operate with dramatically reduced bias force and displacement while maintaining exceptional sensitivity. By integrating an inclined beam that buckles under a preset load and transitions into a softening regime, the design significantly enhances low-frequency responsiveness. A microfabricated prototype with on-chip optical interferometry confirms that this mechanism yields stable post-buckling behavior, extended linearity, and low noise performance. The results highlight a promising strategy for advancing precision sensing in compact, low-power devices.
Conventional enables micro-electro-mechanical systems (MEMS) accelerometers face a trade-off: increasing sensitivity typically requires reducing stiffness or enlarging proofmasses, both of which limit dynamic range and raise fabrication complexity. Nonlinear anti-spring or buckling-beam structures can soften stiffness, but existing designs often demand large bias displacements or exhibit abrupt snap-through behavior, constraining practical applications. Additionally, precision inertial sensing—such as gravimetry, geophysics, structural monitoring, and navigation—requires low noise, low power, broad range, and miniaturization. Traditional linear springs struggle to simultaneously deliver these performance metrics. Due to these challenges, there is a pressing need to explore new stiffness-softening mechanisms that balance sensitivity with range and device compactness.
Researchers at Simon Fraser University and the University of Manitoba have unveiled a nonlinear spring mechanism for MEMS accelerometers, published in Microsystems & Nanoengineering in 2025. The study demonstrates how an inclined beam, loaded eccentrically through a micro-arm, can buckle in a controlled manner to achieve stable stiffness softening. A microfabricated prototype equipped with an on-chip optical interferometer verifies the resulting high sensitivity, reduced bias displacement, and expanded dynamic range. This work introduces a practical strategy for next-generation precision microsensors.
The authors designed a nonlinear MEMS spring structure that uses an inclined beam subjected to an eccentric axial load. Before buckling, the beam behaves like a stiff spring; once the critical force is exceeded, it undergoes controlled buckling and transitions into a low-stiffness, high-sensitivity regime. Finite-element simulations and analytical modeling revealed how beam angle and micro-arm length tune bias force, buckling onset, and stiffness characteristics. Optimal parameters (θ = 60°, d = 300 μm) were selected to achieve substantial stiffness softening without abrupt instability.
A MEMS prototype integrating two nonlinear springs and two linear springs was fabricated on an SOI wafer. An on-chip optical interferometer measured proofmass motion with a displacement noise floor of 40 pm/√Hz. Experiments showed an extended linear operating range exceeding 150 mg, a bias displacement of only 10 μm, and a bias force of 0.3 mN—an order-of-magnitude improvement over traditional pre-curved anti-spring designs. The device also demonstrated a sensitivity of 194°/mg and achieved post-buckling stability dominated by linear springs. These results confirm that the proposed mechanism overcomes long-standing constraints in MEMS stiffness softening by minimizing displacement, suppressing snap-through, and enabling compact form factors (11 × 11 mm²).
“Our results show that an inclined-beam buckling mechanism can reliably deliver stiffness softening with exceptionally low bias displacement,” the research team explained. “By eliminating abrupt snap-through transitions and maintaining stability after buckling, this approach opens the door to ultra-sensitive MEMS sensors that no longer require bulky structures or large proofmass movements. The prototype demonstrates that high precision and large dynamic range can coexist in a compact platform, marking a significant advancement for next-generation inertial sensing technologies.”
This nonlinear spring mechanism offers broad potential for precision sensing applications, including gravimetry, seismic monitoring, spacecraft instrumentation, and low-frequency vibration detection. The dramatically reduced bias displacement enables capacitive or optical readout schemes in smaller form factors, while the extended linear range supports accurate measurement under varying inertial loads. Its compatibility with standard MEMS fabrication suggests strong scalability for commercial devices. Future implementations combining capacitive feedback and integrated temperature monitoring could further enhance stability, making the approach suitable for long-term field deployment and miniaturized multi-axis sensing modules.
References
DOI
10.1038/s41378-025-01066-3
Original Source URL
https://doi.org/10.1038/s41378-025-01066-3
Funding information
This research was financially supported by the Canadian Space Agency (CSA).
Lucy Wang
BioDesign Research
email us here
Legal Disclaimer:
EIN Presswire provides this news content “as is” without warranty of any kind. We do not accept any responsibility or liability
for the accuracy, content, images, videos, licenses, completeness, legality, or reliability of the information contained in this
article. If you have any complaints or copyright issues related to this article, kindly contact the author above.
