基于印刷电路板的沿面型介质阻挡放电特性

Characteristics of Surface Dielectric Barrier Discharge Based on a Printed Circuit Board

沿面型介质阻挡放电(surface dielectric barrier discharge,SDBD)产生大气压低温等离子体技术在生物医学等多个领域具有广泛的应用前景。为此,设计了一种基于印刷电路板(printed circuit board,PCB)制作工艺的SDBD装置,研究了其在正弦交流电压驱动下的放电均匀性、放电模式及形态、放电功率、等离子体发射光谱等光电特性。研究结果表明:随着外施电压幅值和频率的升高,SDBD放电强度与均匀性相应增加,当电压幅值>5.2 kV时可实现宏观上稳定的均匀放电。表面放电由网状电极边沿、介质板与空气三结合点处的收缩状放电向网格内部发展为弥散状放电,外施电压正半周期内的放电强度大于负半周期,这主要是由正负放电中阻挡介质表面电荷对沿面电场抑制作用的差异造成。当SDBD施加的电压幅值在5.0~6.2 kV范围内变化时,由于电场强度和粒子间碰撞频率的增加,使得放电空间注入能量、高能电子数量以及粒子动能均增加,放电程度变强,从而使SDBD放电功率、等离子体发射光谱谱线相对强度、氮分子振动与转动温度均随着电压幅值的增加出现不同程度的升高。

Surface dielectric barrier discharge(SDBD)generating the atmospheric pressure low temperature plasma has broad application prospects in several fields including the biomedicine.In this paper,a SDBD device based on a printed circuit board(PCB)is used and its electrical and optical characteristics including the uniformity,discharge mode and pattern,discharge power together with plasma emission spectra are investigated when the device is driven by a sinusoidal AC power supply.The results show that the discharge intensity and uniformity increase with the raised voltage amplitude and frequency.When the peak-to-peak value of applied voltage is higher than 5.2 kV,the macroscopic stable and uniform discharge will appear.The surface discharge develops into a dispersive discharge inside the grid from the contraction discharge at the three junction points including the fine line edge of the lattice,dielectric material and air.Besides,the discharge intensity during positive half cycle of voltage is stronger than that in the case of negative half cycle,which is mainly caused by the difference of the inhibition of the electric field along the surface by the surface charges in the positive and negative discharges.When the applied voltage amplitude ranges from 5.0 kV to 6.2 kV,due to the enhanced electric field intensity and collision frequency between particles,the energy is injected into the discharge space,and the number of high-energy electrons and the particle kinetic energy are strengthened.As a result,the discharge becomes stronger,which ultimately enables the discharge power of SDBD device,the relative intensity of plasma emission spectra,the vibration and rotation temperature of nitrogen molecules to increase to various degrees with the increasing voltage amplitude.