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

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.