Smart Hydrogel Film Makes Gas Detection Safer for Health and Industry

Identifying the Issue

Existing sensors based on metal oxide semiconductors are limited by high temperature operation, response to different gases (poor selectivity) and non-flexible nature
In this aspect, hydrogels with their interesting physical and chemical properties have attracted in designing the flexible sensors

Objective of the Research

Study the hybrid hydrogels to design gas sensors and tune the properties to high selectivity, with enhanced response for wearable applications

Who should read this?

Research community working on gas sensors, hydrogels, flexible electronics.
Industrial safety experts, and pharmaceutical industry.

Solution

Room temperature operable, flexible hydrogels which are selective to particular target gas interactions. Investigate hybrid hydrogel networks films to enhance the selectivity and sensitivity.

Key Features and Benefits

hybrid hydrogel system formed by Laponite (a synthetic nanoclay) and Sodium Alginate (a natural polyelectrolyte) over the flexible polyethylene terephthalate (PET) substrates
Have shown enhanced response with high selectivity towards ammonia gas sensing
Ammonia interacts through ionization, thus forming NH⁴⁺, which causes releasing of Na⁺ ions in the hydrogel network. This differs from other gases and has resulted in high ammonia selectivity and an enhanced response
Robust performance under humidity, ensuring stability.
Suitable for wearable/health-related applications.

Impact

Achieved a low detection limit of 7 ppm, making it suitable for environmental and biomedical monitoring.
Rapid response (31 s) and recovery (84 s) at 1000 ppm.
The sensing mechanism based on ion-exchange interactions between Na⁺ in the hydrogel and NH₄⁺ which is unique to ammonia with these hybrid hydrogels.

Team