Material and Structural Innovations for High-Performance Flexible Triaxial Force Sensors: A Review

Abstract

The growing demand for precise force measurement in healthcare, robotics, and human-machine interaction systems has driven the development of flexible triaxial force sensors, as traditional rigid force sensors demonstrate significant limitations in adaptability, sensitivity, and multi-directional force decoupling capabilities. Recent material and structural innovations have simplified multi-directional force decoupling and improved key parameters: Sensitivity (237.48% N⁻¹), measurement range (±70 N), long-term stability (performance decay rate <4.2% and hysteresis rate <3.6% under 60,000 cycles of loading) and response time (0.8 ms). This review systematically summarizes research progress in flexible triaxial force sensors and their application potential across multiple domains, with a focused examination of recent breakthroughs in performance optimization strategies and multi-directional force decoupling methods. First, the sensors are categorized according to operational principles, accompanied by in-depth analyses of enhancement approaches for key parameters such as sensitivity. Subsequently, multi-directional force decoupling techniques based on machine learning and its optimization algorithms are summarized. Furthermore, innovative applications in healthcare, robotics, and human-machine interaction are explored. Finally, the necessity of flexible triaxial force sensors in future emerging technologies and the challenges in its development are discussed. Through a comprehensive review and analysis of recent research breakthroughs, this work provides valuable insights to advance future investigations on flexible triaxial force sensors.