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

Area of Science:

• Materials Science
• Flexible Electronics
• Bioinspired Engineering

Background:

• Strain sensors in soft-material and flexible electronics suffer from parasitic signals due to isotropic thermal expansion, particularly affecting crack-based designs.
• Thermally induced crack evolution in sensors can interfere with accurate mechanical deformation measurements.

Purpose of the Study:

• To develop a strain sensor that stabilizes crack geometry under isotropic thermal expansion.
• To enable accurate strain extraction by mitigating parasitic thermal signals in flexible sensors.

Main Methods:

• Introduced a crack-based one-dimensional microspheres array (COMA) inspired by Nostoc morphology.
• Utilized conductive polyaniline (PANI)@ polystyrene (PS) microspheres assembled into grooved elastomers to form discrete, crack-like junctions.
• Integrated the COMA sensor with a multilayer perceptron model for state classification.

Main Results:

• The COMA sensor demonstrated a stable thermal response of 75.2%°C⁻¹ between 20°C-60°C.
• The sensor effectively converts ultralow mechanical deformation (≤0.5%) into pronounced electrical signals.
• Achieved 97.0% accuracy in classifying four operational states of a pouch cell using the integrated model.

Conclusions:

• The bioinspired COMA strategy provides a general approach for creating thermomechanically stable, intelligent flexible sensors.
• This method enhances the reliability and accuracy of strain transduction in flexible electronic systems.
• The developed sensors show potential for multimodal sensing applications in various electronic devices.