High-performance flexible dual strain-temperature sensor based on a sandwich-architecture hydrogel

Area of Science:

• Materials Science
• Biomedical Engineering
• Sensor Technology

Background:

• Developing multifunctional hydrogel sensors for skin-mimicking applications is challenging.
• Existing sensors often struggle to balance skin compatibility, mechanical/thermal sensitivity, and durability.
• High-performance sensors are crucial for wearable electronics and physiological monitoring.

Purpose of the Study:

• To construct a hydrogel sensor with synergistic mechanical and thermal dual-sensitivity.
• To achieve multifunctionalities, including high performance, durability, and skin compatibility.
• To explore its potential in physiological monitoring applications.

Main Methods:

• Fabrication of a sandwich architecture hydrogel sensor using a poly(acrylic acid)-polyacrylamide interpenetrating network.
• Incorporation of poly(N-isopropylacrylamide) for thermosensitivity and a PEDOT:PSS/graphene interlayer for enhanced conductivity.
• Evaluation of mechanical/thermal sensitivities, durability, and conductivity through performance tests.

Main Results:

• The hydrogel sensor demonstrated high mechanical sensitivity (gauge factor up to 25.76) and exceptional durability (>5000 cycles).
• It exhibited pronounced electrical conductivity and outstanding thermal sensitivity (temperature coefficient up to 8.33 pph °C⁻¹).
• The sensor successfully monitored electrical signals from human joint/torso movements and tracked body temperature fluctuations.

Conclusions:

• The developed hydrogel sensor offers a promising solution for skin-mimicking applications requiring dual mechanical and thermal sensing.
• Its high performance, durability, and sensitivity position it as a valuable tool for physiological inflammation monitoring and body temperature tracking.
• This work advances the development of multifunctional wearable sensors for health monitoring.