Strain Redistribution Effect Based Composite Structured Sensor for Decouplable Tactile-Strain Double-Mode Perception

Abstract

A key challenge in electronic skin with dual haptic-stretch sensing is the interference between force-sensitive modes. Existing solutions require complex integration processes or mathematical decoupling models. Effectively decoupling stretch and pressure response in flexible force-sensitive sensors remains a critical task. Herein, a strain redistribution effect (SRE) of composite structural mainframe fulfills the decouple double-mode force-sensitive perception by the aid of a lightweight algorithm. The CAD-assisted design enables the dual-mode sensing structure to be configured as a three-layer stacked composite. Utilizing differential Young's modulus distribution, the strain redistribution effect is achieved across the structured frame. Tensile deformation and tactile pressure are measured via resistance from the strain amplification region and capacitance from the strain suppression region, respectively. Digital Image Correlation (DIC) confirms a 53% deformation in the amplification region under 10% tensile strain, demonstrating a fivefold amplification effect. A lightweight random forest algorithm effectively decouples resistance-capacitance signals, achieving R² values of 0.99 and 0.75 for tensile deformation, and 0.99 and 0.78 for tactile pressure, respectively. This study leverages the strain redistribution effect of the composite structural frame to provide a novel structured integration scheme for the dual-mode decoupled force-sensitive sensing unit, which is expected to be a significant development path.