Fatigue Testing of Wearable Sensing Technologies: Issues and Opportunities

Area of Science:

• Materials Science
• Biomedical Engineering
• Mechanical Engineering

Background:

• Wearable sensing technologies require robust fatigue testing standards, which are currently lacking.
• Existing fatigue tests often focus on proof-of-concept stretch sensors, using diverse materials like polymers, textiles, and nanomaterials.
• Variations in materials and testing methodologies complicate sensor comparisons and reliability assessments.

Purpose of the Study:

• To highlight the absence of standardized fatigue testing protocols for wearable sensors.
• To emphasize the need for consistent methodologies to enable direct comparison of different wearable sensor technologies.
• To advocate for the establishment of standards to facilitate the transition of wearable sensors from research to clinical application.

Main Methods:

• Review of existing fatigue testing approaches for wearable sensors, noting a focus on low-cycle fatigue (LCF).
• Identification of material variations (polymers, textiles, carbon nanotubes, graphene, conductive inks) influencing sensor fatigue behavior.
• Assessment of the limited availability of failure data and high-cycle fatigue (HCF) testing in current research.

Main Results:

• Significant lack of standardized fatigue testing procedures for wearable sensors.
• Predominance of LCF testing, with insufficient data on sensor failure or runout.
• Absence of comprehensive fatigue life predictions for wearable sensor technologies.

Conclusions:

• Standardized fatigue testing is essential for reliable comparison and development of wearable sensors.
• Further research incorporating HCF and failure data is needed for validating predictive models.
• Establishing standards will accelerate the clinical translation of advanced wearable sensing technologies.