单线型低温等离子消融电极的结构设计与实验验证

Structural design and experimental verification of single-wire low-temperature plasma ablation electrode

目的设计一种单线型低温等离子消融电极,解决传统电极难以生成均匀、连续和稳定微气泡的问题,提高低温等离子体的消融与切割效果。方法在SolidWorks 2021三维建模软件中对低温等离子三线型电极与单线型电极结构进行建模,并通过3D打印制作样机。通过COMSOL Multiphysics 6.1软件对2种电极消融过程进行电场和温度场的有限元分析,并通过温度测试实验验证有限元仿真模型的有效性和正确性;通过组织消融实验和低温等离子体激发实验分别比较2种电极的消融效果和等离子体激发过程。结果有限元分析结果显示三线型与单线型电极的表面最高温度分别为70.2、63.3℃,其中单线型电极的表面温度更加理想,2种电极的表面最大电场强度均超过了1.0×10^(7) V/m,达到了微气泡被击穿的电场条件。三线型电极工作电极2端的电场强度远高于其余区域,而单线型电极的电场强度则无明显突变与波动。2种电极表面和距离电极表面1 cm处温度的实验值与仿真值基本一致,拟合度良好,相对误差为3.2%。单线型电极作用在猪脂肪上的消融温度最高为46.8℃,消融后,形态上无焦化区域,在1 s内可达到0.5 mm的组织切割深度。接入能量平台后,单线型电极工作电极表面会产生微气泡;通电6 ms时,工作电极表面完全被微气泡覆盖;通电9 ms时,低温等离子体被激发,可以看到呈蓝紫色光的等离子体;通电25 ms时,产生的微气泡依然规则、稳定。结论设计了一种单线型低温等离子消融电极,可以生成均匀、连续和稳定的微气泡,实现了比传统电极更好的消融与切割效果。

Objective To design a single-line low-temperature plasma ablation electrode,aiming to solve the problem of uniform,continuous and stable microbubbles generated by conventional electrodes,and improve the ablation and cutting effect of low-temperature plasma.Methods The structures of low temperature plasma three-wire electrode and single-line electrode were modeled in SolidWorks 20213D modeling software,and the prototype was made by 3D printing.The finite element analysis of electric field and temperature field of the two kinds of electrode ablation process was carried out by COMSOL Multiphysics 6.1 software,and the validity and correctness of the finite element simulation model were verified by temperature test experiment,and the ablation effect and plasma excitation process of the two kinds of electrode were compared by tissue ablation experiment and low temperature plasma excitation experiment.Results The results of finite element analysis showed that the maximum surface temperature of three-wire electrode and single-wire electrode were 70.2 and 63.3℃,respectively,and the surface temperature of single-wire electrode was more ideal,and the maximum electric field intensity of the two electrodes was more than 1.0×10^(7) V/m,which met the electric field condition of microbubble breakdown.The electric field intensity of the two ends of the three-wire electrode was much higher than that of the other regions,while the electric field intensity of the single-wire electrode had no obvious sudden change and fluctuation.The experimental values of the temperature at the electrode surface and a distance of 1 cm on the electrode surface were basically consistent with the simulation values,the degree of fit was good,and the relative error was 3.2%.The highest ablation temperature of single linear electrode on pig fat was 46.8℃.After ablation,there was no coking area in morphology,and the tissue cutting depth of 0.5 mm could be reached in 1 s.When connected to the energy platform,microbubbles would occur on the working electrode surface of the single-wire electrode;when 6 ms was electrified,the working electrode surface was completely covered by microbubbles;when 9 ms was energized,the low-temperature plasma was excited and the blue-purple plasma could be seen;when 25 ms was energized,the microbubbles were still regular and stable.Conclusions A kind of single-line low-temperature plasma ablation electrode is designed,which can produce uniform,continuous and stable microbubbles and achieve better ablation and cutting effect than the traditional electrode.