A Normal-Stressed Electromagnetic-Driven Stiffness-Tunable Nanopositioner

High-bandwidth and long-range nanoprecision motion is crucially required by many advanced instruments and robotic systems, which rely on the nanopositioners. However, traditional nanopositioners suffer from their fixed stiffness and can only obtain fixed performance, leading to narrow applications. Here, a novel nanopositioner called normal-stressed electromagnetic-driven stiffness-tunable nanopositioner (EDSTN) is presented, which consists of three parts: A normal-stressed electromagnetic actuator to generate the actuation force, a high-stiffness compliant mechanism for guiding the fast precision motion, and a tunable negative stiffness electromagnetic spring to control the overall effective stiffness. The EDSTN realizes a stiffness tuning ratio of 3.24x, enabling an in situ, fast, and continuous performance tuning to meet the changing requirements. It holds promising prospects in constructing highly flexible precision devices, and the implementation of atomic force microscopy measurements on different samples validates its effectiveness. This work provides a new direction to develop versatile nanopositioners.