Advances and future perspectives in hydrogel-based sensing technologies: a comprehensive review

Area of Science:

• Materials Science
• Biomedical Engineering
• Sensor Technology

Background:

• Hydrogels are highly regarded for their water content, biocompatibility, and responsiveness, making them ideal for sensor applications.
• Hydrogel-based sensors are increasingly vital in environmental monitoring, healthcare diagnostics, and wearable technology.
• Existing reviews often focus narrowly on specific hydrogel types or applications, creating a need for a comprehensive synthesis.

Purpose of the Study:

• To provide a comprehensive review of recent advancements in conductive hydrogel sensors.
• To integrate material design, functionalization, and deployment in multifunctional platforms.
• To address a critical literature gap by offering a holistic perspective on conductive hydrogel sensors.

Main Methods:

• Synthesis of recent research on conductive hydrogel sensors.
• Analysis of material design strategies including conductive polymers, carbon nanofillers, and ionic conduction.
• Evaluation of hydrogel sensor applications in human motion detection, cancer monitoring, and UV sensing.

Main Results:

• Development of highly stretchable and conductive hydrogels.
• Demonstration of precise human motion detection and innovative cancer monitoring via non-invasive sweat analysis and intraoperative tumor tracking.
• Achieved sensitive UV monitoring using colorimetric and photoelectrochromic mechanisms for skin health and environmental applications.

Conclusions:

• Conductive hydrogel sensors show significant promise for personalized healthcare, environmental sensing, and soft robotics.
• Challenges such as mechanical fragility, sensitivity/specificity inconsistencies, and long-term stability need to be addressed.
• Future directions include 'smart' hydrogels responsive to multiple stimuli and integration with bioelectronics for advanced monitoring.