Stretchable and Self-Adhesive Humidity-Sensing Patch for Multiplexed Non-Contact Sensing.

Area of Science:

• Materials Science
• Electronics Engineering
• Wearable Technology

Background:

• Flexible humidity sensors often fail due to material slippage during mechanical deformation, leading to baseline drift.
• This failure mode limits the reliability of wearable electronic devices that rely on accurate humidity monitoring.

Purpose of the Study:

• To develop a stretchable, self-adhesive, and transparent humidity-sensing electronic patch with enhanced durability.
• To address the slippage issue in moisture-sensitive materials used in flexible sensors.

Main Methods:

• Fabrication of a humidity-sensing patch using liquid metal particle electrodes with a serpentine structure and a Ti3C2Tx MXene/carboxymethyl cellulose sensing layer.
• Integration onto a soft-hard heterostructure substrate to provide strain isolation.
• Testing of the patch's performance under various tensile strains and humidity levels.

Main Results:

• The patch demonstrated stable humidity sensing up to 100% tensile strain with autonomous skin adhesion.
• Achieved a maximum response of 1145.4% at 90% relative humidity (RH), fast response/recovery times (1.4/5.9 s), and high sensitivity (64.63%/% RH).
• Preserved sensing capabilities under deformation and showed scalability for multiplexed detection.

Conclusions:

• The developed electronic patch offers a robust solution for reliable humidity sensing in wearable applications.
• The strain-isolation strategy is extendable to other materials, enabling the creation of advanced stretchable electronic skin patches.
• Potential applications in healthcare and environmental monitoring were demonstrated.