Three-dimensionally deformable, highly stretchable, permeable, durable and washable fabric circuit boards

Area of Science:

• Materials Science
• Textile Engineering
• Electronics Engineering

Background:

• Wearable electronics require flexible, durable, and washable circuit boards.
• Existing flexible circuits often lack sufficient mechanical robustness and longevity.

Purpose of the Study:

• To develop and characterize novel fabric circuit boards (FCBs) for advanced wearable applications.
• To evaluate the mechanical, electrical, and durability performance of knitted FCBs.

Main Methods:

• Computerized knitting technology used for fabrication under ambient dry conditions.
• Unidirectional tensile tests and 3D ball punch tests to assess strain tolerance.
• Fatigue testing and washing cycles to evaluate durability and reliability.

Main Results:

• Knitted FCBs demonstrate <1% resistance change at 300% strain (unidirectional) and 150% strain (3D).
• Achieved over 1,000,000 loading cycles at 20% strain and retained functionality after 30 washes.
• Exhibited superior performance compared to existing metal-coated films and organic materials.

Conclusions:

• The unique knitted structure effectively mitigates strain in conductive fibers, ensuring excellent mechanical and electrical properties.
• FCBs are highly suitable for next-to-skin electronic devices and smart apparel.
• Demonstrated potential for in situ measurement in smart protective gear during ballistic impacts.