Preparation And Study Of Fiber-based Flexible Ultraviolet Sensor And Triboelectric Generator

With the fast development of the electronic technology,there is an increasing demand to the wearable electronic devices.They should possess not only excellent performance to fulfill some functionalities that are closely related to our daily life,but also the property of flexibility and light weight to reduce the wearers' discomfortableness.Therefore,exploring and further fabricating wearable electronic devices with good property have been one of the main study directions for the development of flexible electronic devices.Through carefully harmonizing the polymer's low thermal decomposition temperature and high reaction temperature for preparing Zn O nanowire via chemical vapor deposition(CVD)method,we developed a new approach to prepare Zn O nanowires on flexible polymer substrates(Kapton film and Kevlar fiber).Well aligned Zn O nanowires array with good crystallinity was obtained by adjusting the amount of the zinc source and the gases.The morphology of Zn O nanowires grown at different temperatures was investigated and it changes from needlelike structure to goblet-like structure,and further to cylindrical structure,when the temperature increases from 380 °C to 510 °C.For the growth of Zn O nanowires array at 507 °C,by adjusting the growing time,the NW's average length and diameter can be well controlled from 0.5 ?m to 2.76 ?m,and 30 nm to 300 nm,respectively.The fiber grown with Zn O nanowires array was bent into the character like “LZU”,which exhibits good flexibility.Then based on the Kevlar fiber/Zn O nanowires array hybrid structure,flexible ultraviolet(UV)sensor with good performance was made to detect UV illumination quantificationally,which is important to fabricate wearable UV sensor for real-time monitoring the UV illumination intensity.With the massive appearance of wearable electronic devices,how to power them has been a big challenge.Harvesting and converting energy of body motions into electricity provides a promising way toward solving this challenge.Here,we fabricated a kind of core-shell hybrid fibers made up of nylon and polyester fibers through a simple and cost-effective method.Then,based on these hybrid fibers,we developed a type of flexible triboelectric nanogenerator(TENG)with double-helix structure.It can effectively convert the mechanical energy into electricity.And then,in order to improve its output performance,an integrated TENG was made using the core-shell hybrid fibers through weaving process.Its structure is the same with that of the common cloth,which makes it very soft and flexible.An integrated fiber-based TENG with a size of 14 mm × 15 mm could well convert the mechanical energy into electricity with an output current and output voltage of 575 n A and 6.35 V,respectively.And it has the strong ability to harvest the weak mechanical energy of human body motions with different intensities,different directions as well as different forms.And its output can successfully light up a commercial light-emitting diode,which shows its potential ability as a power source for low power consumption electronics.