Stretchable Tri-Axis Sensor for Tires: Investigating Pressure, RPM, Camber, Slip, and Deformation Effects

Abstract Accurate monitoring of tire parameters is crucial for improving vehicle safety, efficiency, and predictive maintenance. This study presents the development and evaluation of a stretchable tri-axis sensor designed for tires. The sensor consists of four distinct layers, including ionic liquid-based pressure-sensitive regions for normal, lateral, and longitudinal axis sensing, with multi-walled carbon nanotube (MWCNT) electrodes to ensure reliable electrical response. The fabrication process combines screen printing and molding techniques. Both static and dynamic experiments were conducted to assess the sensor’s performance. Static experiments confirmed that normal axis loading minimally affects lateral and longitudinal taxels, while tangential forces cause predictable voltage drops in the normal taxel due to electrode displacement. In dynamic testing, the sensor was integrated into the inner liner of a miniature pneumatic tire and evaluated the sensor performance under varying deformations (2 mm, 4 mm, and 6 mm), rotational speeds (21 RPM, 42 RPM, and 63 RPM), air pressures (10 psi, 25 psi, and 40 psi), camber angles (+ 6°, + 3°, and 0°), and slip angles(+ 9°, + 6°, and + 3°). Results demonstrated that the sensor successfully captured tire contact patch variations and multi-axis force interactions, though mechanical crosstalk, strain-rate dependency, and directional sensitivity limitations were identified. The proposed sensor presents a promising solution for tire health monitoring, intelligent tire systems, waste reduction and next-generation automotive applications.