How To Make Micro/nanofibrous Structures Direct Written On An Insulating Substrate

As a mass of charge accumulates on the deposited nanofiber, it is difficult to achieve patterned deposition on the insulating substrate. Zheng et al. demonstrated direct writing of orderly micro/nanofibrous structures on a flexible insulating polyethylene terephthalate (PET) substrate utilizing an AC electrical field. The charge transfer characteristics in the jet are changed and the Coulomb repulsive force from the residual charges on the deposited structure is reduced with the help of the applied AC voltage, as shown in Fig. 9.11A and B. Thus a stable jet can be built up and orderly structures, as shown in Fig. 9.11C, can be collected on the PET substrate. From the experimental results, the minimum motion velocity of substrate required to direct write a straight line is 700 mm/s and the line widths of direct-written fibrous structures are in the range of 10-40 μm.

How to Do ALTERNATING CURRENT ELECTROHYDRODYNAMIC DIRECT WRITING

Due to the strong Coulomb repulsive force, direct writing of conductive patterns on an insulating substrate is of great difficulty for NFES. An AC electrical field has been introduced to change the transfer characteristics of the charge along the jet, by which the Coulomb repulsive force can be weakened and the stability of the charged jets can be improved. Nguyen and Byun used a nozzle that was not connected electrically to overcome the electrical breakdown in a conventional NFES system. As shown in Fig. 9.9, an AC voltage is applied to an extraction electrode and the reflection of charged droplets due to patterned geometry on the substrate decreases owing to the patterned geometry on the substrate. Under the AC voltage, positively and negatively charged droplets can be obtained. With the alternation of positive and negative voltage, the jet will be turned to an electrically neutral state, which is helpful for the continuous ejection of droplets even at the peak signal of voltage. Based on the single AC potential setup, dots with sizes ranging from 10 to 30 mm were generated on the substrate. Zheng et al. investigated the effects of process parameters on the microdroplet ejection behaviors under the AC electrical field. The deposition frequency increases and the droplet diameter decreases with increasing AC voltage frequency. In addition, the deposition frequency and droplet diameter increase with increasing duty cycle and solution supply rate. Based on the aforementioned research, Liu et al. printed a bead-on-string structure under an AC electric field. The positive voltage drags out more solution and form beads, while the negative pulse voltage provides the opposite force to stretch the jet into nanofibrous structures between two adjacent beads. The stability of the jet can be enhanced by increasing the voltage frequency. As the voltage frequency increases from 10 to 60 Hz, the diameter of the bead structure decreases from 200 to 110 mm, as presented in Fig. 9.10.

How To Fabricate ZnO Gas Sensor Using Near-Field Electrospray

In addition, a thin-film ZnO gas sensor was fabricated by using near-field electrospray, as shown in Fig. 9.8. Comb electrodes with a large contact area were printed to increase the sensitivity of micro/nanosensors. The electrospray micro/nanoparticles were deposited over the electrodes, which would be heated and oxidized to form a ZnO semiconductor at 500℃ afterward. The experimental results showed that the fabricated sensor displays high sensitivity because of the small diameter and high specific surface area of the electrospray particles, indicating a new promising method for the integration fabrication of micro/nanodevices.

Nanoscale Diameters

Nanofibers with nanoscale diameters are attractive for their wide applications, ranging from envi ronment to energy, electronics, and health care. As the diameters of electrospun fibers are usually larger than 100 nm, several approaches, such as jet stretch enhancement, coreeshell or multicom ponent spinning, and spinning of extremely diluted solutions, have been proposed to further decrease the fiber diameter. However, the limited thinning capacity (usually >50 nm) and low production still remain. Electronetting, as a polymer processing technology, achieves the large-scale fabrication of 2D nanonet materials with nanoscale diameters. The average diameter of the interlinked nanowires in nanonets is about 10e30 nm, which is about 1 order of magnitude smaller than that of conventional electrospun fibers. For example, the major distribution region of nanowires in PAA nanonets reported by Wang and coworkers is 10e20 nm, while for PA-6 nanonets, each nanowire has a uniform diameter of w26 nm, as shown in Fig. 8.6. Benefiting from the extremely small diameter, the resultant nanonet membranes usually show enhanced surface area compared with the common electrospun nanofiber membranes. According to the results of

Foshan Lepton Precision M&C Tech Co.,Ltd Qualification Honor

Foshan Lepton Precision M&C Tech Co.,Ltd Qualification Honor

Foshan Lepton Precision M&C Tech Co.,Ltd Development History

In 2004, electrospinning research team was founded;

In 2006, first proposed Near-Field electrospinning theory;

In 2014, Foshan Lepton Precision M&C Tech Co.,Ltd was founded as the platform in electrospinning industrialization;

In 2016, got the High-tech Enterprise Certificate;

In 2017, the company's chief technical adviser was awarded "intelligent manufacturing star" in Foshan high-tech industrial development zone;

In 2018, it was listed as a warehousing technology enterprise in Guangdong province.

Foshan Lepton Precision M&C Tech Co.,Ltd Company Profile

        Based in Foshan National HighTech Industries Development Zone, Foshan Lepton Precision M&C Tech Co.,Ltd (Qingzi Nano) is a national hightech enterprise which dedicate to the research and development of electrospinning and eletrospraying printing techniques.  We manufacture, sale and provide technical support for electrospinning and electrospraying machines, electrospun nanofiber production line, bioscaffold 3Dprinter and nanofiber products.

         With our powerful and innovative research and development team, Qingzi Nano has established close cooperation with Nanyang Technological University, Xiamen University, Tsinghua University, Sun Yatsen University, South China University of Technology, Guangdong University of Technology and Jinan University. Our techniques and products have been widely applied in the field of environment, energy, electronics, biomedical etc. Our electrospinning products have been awarded as innovative hightech products.

        Qingzi Nano owns more than 80 patents, including over 50 patents for inventions on the techniques and equipment of electrospinning, bio-3D printing and electrospray printing.