Ultra-Stretchable Interconnects for High-Density Stretchable Electronics.

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Stretchable electronics (SE) are crucial for advanced medical diagnostics.
• Miniature SE devices require high-density, extremely stretchable interconnects.
• Standardized microfabrication processes are needed for SE interconnects.

Purpose of the Study:

• To develop CMOS-enabled, free-standing interconnect structures for high-density SE devices.
• To achieve extreme stretchability in microfabricated interconnects.
• To ensure compatibility with standard integrated circuit (IC) microfabrication.

Main Methods:

• Utilized complementary metal-oxide semiconductor (CMOS)-type microfabrication.
• Employed Flex-to-Rigid (F2R) post-processing to create free-standing interconnects.
• Exploited 3D kinematic freedom (buckling, torsion, bending) for stretchability.

Main Results:

• Achieved elastic stretchability over 2000% and ultimate stretchability over 3000%.
• Demonstrated <0.3% resistance change at maximum elastic stretch.
• Showcased >10 million cycles at 1000% stretch with <1% resistance change.

Conclusions:

• Introduced a generic technology for routine microfabrication of highly stretchable interconnects.
• This approach enables novel, highly stretchable miniature devices.
• The developed interconnects offer exceptional performance and reproducibility.