High-Performance, Strain-Stable Electromagnetic Shielding Materials Enabled by Magnetic Elastic Fiber Networks...

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Wearable electronic devices require reliable electromagnetic interference (EMI) shielding in diverse electromagnetic environments.
• Achieving ultra-thinness, high shielding efficiency (SE), and dynamic stability simultaneously is a significant challenge for stretchable EMI shielding materials.

Purpose of the Study:

• To develop an ultrathin, elastic EMI shielding film with high shielding efficiency and excellent dynamic stability.
• To leverage the magnetoelectric synergy effect and a pinning-interlocking mechanism for enhanced performance.

Main Methods:

• Fabrication of an ultrathin elastic EMI shielding film (TPU/Fe-LM) using ferromagnetic elastic nanofiber networks and embedded liquid metal (LM).
• Characterization of EMI shielding performance across a broad frequency range (0.1 MHz to 40 GHz).
• Evaluation of material stability under tensile strain (up to 100%).

Main Results:

• The 85 µm thick film achieved an average EMI SE exceeding 70 dB.
• Shielding performance showed only a 2.59% variation under 100% tensile strain.
• Demonstrated a high EMI SE per unit thickness (SSE = 1225 dB mm⁻¹ @ 100% strain).

Conclusions:

• The developed TPU/Fe-LM film offers exceptional EMI shielding and strain stability, outperforming existing stretchable materials.
• The material shows significant potential for enhancing electromagnetic protection in wearable electronics.
• Integration into a stretchable capacitive strain sensor demonstrated a 50-fold enhancement in angle resolution for robotic motion monitoring.