Fast‐Response, Low‐Hysteresis, Anti‐Creep Soft Capacitive Strain Sensor Based on Oxidized Liquid Metals and Modified Elastomer

ABSTRACT The dynamic measurement capabilities of soft strain sensors are crucial for accurately monitoring dynamic strain in human motion and soft robotics. The accuracy of dynamic measurements is governed by response speed, hysteresis, and creep. However, the existing soft strain sensors suffer from the modulus mismatch of electrode and elastomer as well as the inherent viscoelasticity of the elastomer, resulting in low accuracy in dynamic measurements. This paper presents a fast‐response, low‐hysteresis, anti‐creep soft capacitive strain sensor (SCSS) based on oxidized liquid metals (oLMs) and modified elastomer, which can achieve accurate real‐time dynamic measurement. The SCSS comprises liquid metal interdigital electrodes (LMIEs) encapsulated within a modified elastomer reinforced with nano‐silica (SiO 2 ) particles. LMIEs are fabricated using oLM, which exhibits low surface tension and excellent fluidity. This approach eliminates the modulus mismatch between the electrode and elastomer, thereby reducing hysteresis. Meanwhile, crosslinking control and nano‐SiO 2 addition produce an elastomer with high elastic recovery properties and optimal chain segment mobility, mitigating intrinsic viscoelasticity. The SCSS demonstrates fast‐response (response time ≈ 0.12 s, response speed ≈ 7.82 pF/s), low‐hysteresis, and anti‐creep properties, achieving a gauge factor (GF) of 0.438 and a measurement range of 0%–80%. Furthermore, the tensile force sensitivity is 2.9 × 10 7 times greater than normal force sensitivity, effectively suppressing interference from normal forces and enabling precise tensile strain measurement. The SCSS has applications in the field of wearable health monitoring, human‐machine interaction, and soft robotics.