Scalable Manufacturing of Solderable and Stretchable Physiologic Sensing Systems

Area of Science:

• Materials Science
• Biomedical Engineering
• Microfabrication

Background:

• Developing advanced wearable sensors for continuous health monitoring is crucial.
• Existing systems often face challenges with integration, durability, and unobtrusiveness.

Purpose of the Study:

• To present methods for microfabricating solderable and stretchable sensing systems (S4s).
• To demonstrate scaled production of adhesive-integrated S4s for health monitoring applications.
• To showcase the versatility and modularity of S4s for various health sensing needs.

Main Methods:

• S4s fabrication using sputter-deposited nickel-vanadium and gold pads with copper interconnection for solderability.
• Utilizing a donor substrate with "PI islands" for selective adhesion and integration with large-area adhesives.
• Integrating S4s with strain gauges and optical circuits for health monitoring demonstrations.
• Testing Tegaderm-integrated S4 respiration sensors for robustness, stretchability, durability, and biocompatibility.

Main Results:

• Achieved excellent solderability of S4s through specific metal layers and interconnection.
• Demonstrated heterogeneous device integration with large-area adhesives via modified donor substrates.
• Successfully reflow-soldered commercial surface mount components onto S4s, highlighting modularity.
• Validated S4 respiration sensors for cyclic deformation, stretchability, durability, and multiday wear.

Conclusions:

• Adhesive-integrated S4s offer a versatile and modular platform for unobtrusive health monitoring.
• Compatibility with standard printed circuit board assembly processes facilitates scaled production.
• The developed S4s show significant potential for advanced wearable health monitoring systems.