An Ultrastable Ionic Chemiresistor Skin with an Intrinsically Stretchable Polymer Electrolyte

Area of Science:

• Materials Science
• Chemical Sensors
• Biomedical Engineering

Background:

• Volatile organic compounds (VOCs) in exhaled breath are potential biomarkers for diseases like lung cancer.
• Developing reliable and wearable biosensors for continuous monitoring remains a challenge.

Purpose of the Study:

• To design and characterize an ultrastable ionic chemiresistor skin (ICS) for sensitive VOC detection.
• To evaluate the ICS performance under various environmental and mechanical stress conditions.
• To explore the potential of ICS as a skin-attachable biosensor for early disease diagnosis.

Main Methods:

• Fabrication of an intrinsically stretchable thermoplastic polyurethane electrolyte film for VOC sensing.
• Hierarchical assembly and characterization of the polymer electrolyte film for uniformity and ion distribution.
• Systematic experimental and theoretical studies to understand sensing mechanisms and reliability.
• Testing ICS sensitivity and stability with representative VOCs found in human breath.

Main Results:

• The ICS exhibits a uniform, transparent, and intrinsically stretchable polymer electrolyte film.
• Even ion distribution within the polyurethane matrix ensures high device reliability.
• Highly sensitive and stable detection of VOCs like toluene, hexane, propanal, ethanol, and acetone.
• The sensor maintains full operability after prolonged storage, harsh environmental conditions (85% RH, 100 °C), and severe mechanical deformation (1 mm bending radius, 100% strain).

Conclusions:

• The developed ICS demonstrates exceptional stability and sensitivity for VOC detection.
• The ICS platform is robust against environmental and mechanical challenges, suitable for real-world applications.
• This technology offers a promising approach for human-adaptive, skin-attachable biosensors for daily monitoring and early disease diagnosis.