(Nanowerk News) Researchers in China propose a facile and effective strategy for the preparation of self-healing and highly sensitive strain sensors based on metal-ligand coordination and hierarchical structure design for diverse human activity monitoring.
First, they developed a stretchable and autonomously self-healing elastomer cross-linked by metal-ligand coordination bonds. The as-prepared elastomer exhibited desirable self-healing ability in various harsh conditions.
Then, on the basis of this self-healing material, the researchers constructed electronic sensors with a hierarchical structure by assembling a self-healing substrate and a nanostructured conductive layer.
The fabricated sensors showed eminent electrical self-healing capacity, high sensitivity, and good stability, which could be used to capture both subtle physiological signals and large-scale body motions after the cutting/healing process.
The team evaluated the capability of their sensors in several ways: One was in speech recognition via monitoring the motions of the vocal muscle. When the tester pronounced “hi”, “hello”, and “how are you”, current signals of a self-healed sensor were recorded in real-time.
Another was in capturing subtle physiological activities, where the insulating side of a self-healed sensor was directly attached to the neck to monitor the muscle motions near the throat. When the tester coughed and swallowed, current changes of the self-healed sensor were recorded in real-time using an electrical analyzer.
The authors point out that, even after suffering harsh treatments – repeated bending and washing – the self-healed sensors could still detect tiny human activities.
These remarkable properties enable the prepared sensors to be promising in manufacturing smart electronic devices, such as wearable devices, electronic skin, and healthcare equipment.