Hierarchical Structural-Interfacial Engineering with Dynamic Soft-Hard Cross-Linking Enables Full-Range,...

Area of Science:

• Materials Science
• Nanotechnology
• Sensor Technology

Background:

• Flexible piezoresistive sensors are inspired by human tactile perception but face challenges in achieving high sensitivity, wide pressure range, and mechanical robustness simultaneously.
• Existing sensor designs struggle to balance these critical performance metrics, limiting their application scope.

Purpose of the Study:

• To develop a novel hierarchical stress-regulation strategy for designing advanced flexible piezoresistive sensors.
• To overcome the limitations of current sensors by integrating multiscale surface microstructures and a dynamically cross-linked sensing network.

Main Methods:

• A hierarchical stress-regulation strategy was employed, integrating multiscale surface microstructures with a dynamically cross-linked MXene/carboxymethyl cellulose/borax sensing network.
• Replicated microtopographies were used to induce progressive stress localization, while heterogeneous soft-hard cross-linking regulated nanoscale deformation.
• The coupled structural-interfacial regulation generated abundant stress-concentrated sites and stabilized conductive pathways.

Main Results:

• The developed sensor demonstrated ultrahigh sensitivity (774.48 kPa^-1) and a wide working pressure range (334.16 kPa).
• Fast response and recovery times (8.58/17.22 ms) were achieved, enabling reliable capture of both subtle physiological signals and large mechanical loads.
• The sensor supported applications such as gesture recognition and robotic control when integrated with real-time feedback and machine learning.

Conclusions:

• The hierarchical stress-regulation strategy provides a general framework for designing robust, full-range tactile sensors.
• This approach successfully addresses the long-standing challenge of simultaneously achieving high sensitivity, wide pressure range, and mechanical robustness in flexible piezoresistive sensors.
• The findings pave the way for next-generation tactile sensing technologies in various fields.