In a major leap forward for microelectromechanical systems (MEMS) technology, researchers have unveiled a novel miniaturized accelerometer that can boost sensitivity, reducing noise and bias instability while maintaining compact chip size. The innovation centers around a novel anti-spring mechanism featuring pre-shaped curved beams, which enables stiffness softening without requiring large bias forces or displacements. This design not only enhances performance but also maintains a compact form factor, making it highly suitable for applications ranging from earthquake detection to structural health monitoring.
Microelectromechanical systems (MEMS) accelerometers play a critical role in high-precision applications such as gravity measurement, structural health monitoring, and inertial navigation. However, improving their resolution has long been a challenge due to limitations in noise floor and sensitivity. Conventional approaches often rely on bulky proof mass and complex structures. The need for a more compact and high-sensitive accelerometer that overcomes these constraints has driven researchers to explore novel design strategies.
Now, a team from ShanghaiTech University and the Shanghai Institute of Microsystem and Information Technology has addressed this challenge with a novel design. Their research (DOI: 10.1038/s41378-024-00826-x) , published in Microsystems & Nanoengineering on March 5, 2025, introduces a MEMS accelerometer featuring an advanced anti-spring mechanism. By employing two pre-shaped curved beams, this mechanism enables stiffness softening with reduced bias force and displacement—achieving a 10.4% increase in sensitivity while reducing the noise floor and bias instability.
The core of this innovation is the anti-spring mechanism, which consists of two clamped-clamped pre-shaped curved beams arranged in parallel. Unlike existing designs that require large proof mass to enhance sensitivity, this approach achieves the same effect by significantly reducing the required bias force and bias displacement for achieving quasi-zero stiffness. The required bias force and displacement are reduced by an order of magnitude compared to conventional approach. The research team validated their concept through both theoretical modeling and finite element method (FEM) simulations. A fabricated prototype, with a core chip size of just 4.2 mm × 4.9 mm, demonstrated a 10.4% increase in sensitivity of 51.1 mV/g, a 10.5% reduction in noise floor of 21.3 μg/√Hz—providing a feasible pathway for enhancing the performance and miniaturization of MEMS accelerometers.
"This novel anti-spring mechanism marks a significant advancement in MEMS accelerometer technology," said Dr. Fang Chen, one of the lead researchers. "By enabling stiffness softening with minimal bias force, we have not only enhanced sensitivity but also achieved a more compact and integrable design. This breakthrough opens new doors for high-precision sensing in a variety of fields."
The impact of this research extends across multiple industries, particularly in applications requiring precise acceleration measurements. The compact and high-performance design makes this accelerometer ideal for building high-density, low-cost, and high-precision acceleration measurement system and network. Future research will focus on refining bias tuning structures and optimizing interface circuits to further improving the MEMS accelerometer performance.
