A Crack‐Based One‐Dimensional Microspheres Array Enables Thermal–Mechanical Decoupled Dual‐Functional Sensing

ABSTRACT Strain sensors in soft‐material and flexible‐electronic systems face a fundamental challenge: isotropic thermal expansion can generate parasitic signals that obscure true mechanical deformation. This issue is particularly severe in crack‐based sensors, whose extreme morphological sensitivity causes thermally driven crack evolution to interfere with strain transduction. Inspired by the bead‐chain morphology of Nostoc , we introduce a crack‐based one‐dimensional microspheres array (COMA) that stabilizes crack geometry under isotropic expansion, enabling a predictable, monotonic thermal response from which true strain can be accurately extracted. Conductive polyaniline (PANI)@ polystyrene (PS) microspheres unidirectionally assembled into grooved elastomers form discrete, crack‐like junctions that convert ultralow mechanical deformation (≤0.5%) into pronounced electrical signals. The COMA sensor exhibits a stable thermal response of 75.2%°C ⁻¹ (20°C–60°C) and, when integrated with a multilayer perceptron model, classifies four operational states of a pouch cell with 97.0% accuracy. This bioinspired and structurally guided strategy establishes a general approach for constructing multimodal, thermomechanically stable, intelligent flexible sensors.