Polyurethane-polypyrrole hybrid structural color films for dual-signal mechanics sensing.

The monitoring of mechanical indexes involved in body movement has attracted immense interest in the diagnosis of neurodegenerative diseases. Here, we present a hybrid flexible conductive structural color (SC) film with the capability of dual-signal mechanics screening. The film is constructed by oxidatively polymerizing pyrrole on the surface of an inverse opal polyurethane (IPU) membrane, which can be utilized to measure the mechanical indexes through resistance change. Owing to the inverse opal structure, the film shows visual structural color change when stretched and released according to the body movement. Additionally, the highly uniform ordered porous structure endows the conductive film with a lower coefficient of variance on relative resistance change. Benefiting from these features, we have demonstrated that such a flexible conductive SC film could monitor Parkinson's disease (PD) by detecting mechanical indexes simultaneously via dual signals. These features indicate the great value of the stretchable conductive SC films in mechanics sensing applications.