Self-powered ultrasensitive and highly stretchable temperature-strain sensing composite yarns

Area of Science:

• Materials Science
• Wearable Electronics
• Nanotechnology

Background:

• The development of advanced wearable devices necessitates materials capable of performing multiple functions, including sensing, energy storage, and electrical conduction.
• Existing materials often struggle to maintain functionality under significant elastic deformation, limiting the integration and autonomy of wearable systems.

Purpose of the Study:

• To create a single, stretchable material that integrates strain sensing, temperature sensing, and thermoelectric power generation.
• To develop a yarn-based transducer using PEDOT:PSS coated Lycra® for advanced wearable applications.

Main Methods:

• Coating commercially available Lycra® yarns with PEDOT:PSS to create a trimodal, stretchable yarn.
• Extensive characterization of the yarn's mechanical, sensing, and thermoelectric properties.
• Integration of the yarn into a thermoelectric module for self-powering demonstration.

Main Results:

• Achieved ultrahigh and tunable strain sensitivity (gauge factor ~3.6 × 10^5 at 10-20% strain) with a high strain-at-break point (up to ~1000%).
• Demonstrated stable thermoelectric behavior (Seebeck coefficient of 15 μV K^-1) enabling temperature sensing and self-powering (~0.5 μW).
• The PEDOT:PSS-Lycra yarns exhibited trimodal functionality: strain sensing, temperature sensing, and thermoelectric power generation.

Conclusions:

• The developed PEDOT:PSS-Lycra yarn is a promising material for creating compact, functionally-integrated, and autonomous wearable systems.
• This material can be interfaced with microcontrollers for developing Internet-of-Things (IoT) devices with diverse form factors.
• The trimodal functionality eliminates the need for external power sources in certain wearable applications.