Wearable Ultrathin Self-Powered Sensing System Enabled by 3D Network CNTs-BP/MOF Film

Flexible self-powered pressure sensing devices possessing advantages of comfortable wearing and multifunctionality have been applied in various important fields including sports health, medical treatment, and intelligent electronics. However, it is still restricted by the poor versatility of the materials and the cumbersome structure of the devices. Here, we successfully prepared a thin carbon nanotubes-black phosphorus/metal-organic framework (CNTs-BP/MOF) film with a three-dimensional porous microstructure on a flexible polyethylene terephthalate substrate by ultrasonic chemical method, which exhibits excellent energy storage in supercapacitors and sensing capabilities in pressure sensors. Specifically, the supercapacitor electrode shows a high specific capacitance of 401.4 mF g^-1, low impedance of 25.6 Ω, and excellent cycle stability (99% capacity retention rate over 10,000 cycles). Moreover, the pressure sensor exhibits a sensitive and stable response within the range of 100-2,000 kPa, an excellent magnification of 118 at 2,000 kPa, a rapid response/recovery time of 15/10 ms, and good flexibility. Ultimately, a CNTs-BP/MOF film-based self-powered sensing device with a thickness of only 2.68 mm was fabricated, which can be adhered to the skin at the joints of the human body to precisely monitor various physiological signals. This research is expected to provide useful references for the design of self-powered flexible wearable material structures and devices.