Flexible stimuli-responsive materials for smart personal protective equipment

Flexible stimuli-responsive materials are deformable, stretchable, light-weight, and desirable for smart personal protective equipment (PPE), and as the primarily functional components in the wearable system which spontaneously respond to surrounding variations. These materials enable the traditional PPE who provide passive protection to be smart with the abilities of sensing, actuating, surface changing and self-healing, which enhances the protection and reduces the unintentional occupation injuries. This article presents a critical review of the structure, properties, fundamental mechanisms and current development of flexible stimuli-responsive materials and their potential/present applications to smart PPE, covering strain, pressure, temperature, and gas sensors, biopotential electrodes, exosystems, switchable wetting surfaces and biosafety masks. Scientific and practical challenges along with critical issues and opportunities are also discussed.