Deformable, transparent, high‐performance, room‐temperature oxygen sensors based on ion‐conductive, environment‐tolerant, and green organohydrogels

Abstract

We present green organohydrogel-based stretchable (up to 700% strain), transparent, and room-temperature O 2 sensors with impressive performance, including drying and freezing tolerances, high sensitivity, broad detection range (100 ppm-100%), long-term stability, low theoretical detection limit (0.585 ppm), linearity, and the capability to real-time monitor human respiration by directly attaching on human skin. A facile solvent replacement approach is employed to partially exchange water with natural and edible xylitol/sorbitol molecules, generating stable, green and tough organohydrogels. Compared with the pristine hydrogel counterpart, the organohydrogel-based O 2 sensors feature higher stability, prolonged life time (140 days) and the ability to work over a wide range of temperatures (À38 to 65 C). The O 2 sensing mechanism is elucidated by investigating the redox reactions occurred at the electrode-hydrogel interface. This work develops a facile strategy to fabricate stretchable, transparent, and high-performance O 2 sensor using stable and green organohydrogels as novel transducing materials for practical wearable applications. K E Y W O R D Santi-freezing and anti-drying hydrogel, conductive and green organohydrogel, redox reaction sensing mechanism, stretchable and room-temperature oxygen sensor, xylitol and sorbitol Yuanqing Lin and Zixuan Wu contributed equally to this work.

Self-Powered Respiratory Monitoring Strategy Based on Adaptive Dual-Network Thermogalvanic Hydrogels

“…The Se variation of the thermocouples of the two gels over 7 days immediately confirms that the PVA/GEL-GL gel is capable of long-term operation in comparison to PVA/GEL gels (Figure d). Although many high-performance wearable sensors based on desiccation- and freeze-resistant hydrogels have been reported, these hydrogels tend to be expensive and complex to prepare. − The preparation process of the PVA/GEL-GL hydrogel is simple, and it is more economical.…”

Recent Progress on Flexible Room-Temperature Gas Sensors Based on Metal Oxide Semiconductor

“…Hydrogel is a 3D network-structured polymeric material formed by chemical or physical cross-linking and swelling in abundant water [187,188]. Recently, novel ion-conductive hydrogel gas sensors have been proposed as one of the most promising flexible wearable sensors due to the tunable 1 3 sensing properties, RT operation, excellent stretchability, transparency, biocompatibility, and facile synthesis process [189][190][191].…”

Stretchable, self‐healable, and breathable biomimetic iontronics with superior humidity‐sensing performance for wireless respiration monitoring

“…Currently, extensive research is devoted to the realization of the basic tactile perception of the skin, including strain, temperature, and pressure 38–42 . Equally important, there are some vital external stimuli that human skin is not sensitive enough to, such as humidity and gas, and their monitoring is also of great significance to our real life 43–46 . Accurate humidity monitoring can not only promote the improvement of living comfort, but more importantly, it can be used for human physiological monitoring, such as respiratory rate (RR), respiration arrest, and skin wetness, thus providing clinical information for disease diagnosis, prevention, and rehabilitation.…”