A hydrophobic, self-powered, electromagnetic shielding PVDF-based wearable device for human body monitoring and protection.

With the rapid development of the electronics, information technology and wearable devices, the problems of the power crisis and electromagnetic radiation pollution are emerged. A piezoelectric wearable textile combining with electromagnetic shielding performance becomes a favorable solution. Herein, a multifunctional PVDF-based wearable sensor with both electromagnetic shielding function and human body monitoring performance is proposed by incorporating silver nanowires (Ag NWs) and multiwall carbon nanotubes (MWCNTs) hybrid-networks into PVDF casted commercial non-woven fabrics (NWF). The coordination of Ag NWs and MWCNTs networks ensures the ideal electrical conductivity and mechanical strength. The maximum shielding value of the developed sensor reaches up to 34 dB when the implement of the Ag NWs and MWCNT are kept at 1.9 mg/cm2 and 2.0 mg/cm2, respectively. Besides, the hydrophobicity of the as-proposed sensor (water contact angle ∼ 110.0°) ensures the self-cleaning function and makes it resistive against water and dirt. Moreover, the sensor possesses force-sensing property by generating different piezoelectric voltages (0 V, 0.4 V, 1.0 V and 1.5 V) when stimulated by various forces (0 N, 20 N, 44 N and 60 N). Not only can it respond to different external stress in a timely manner (response sensitivity ∼ 0.024 V/N, response time ∼ 35 ms), but it can also monitor different body movements, such as joint bending, running and jumping. This work opens up a new prospect of monitoring human body as well as protecting human health from electromagnetic radiation surroundings.