Study On Laser Manufacturing And Forming Of Metal Dry Electrode With Surface Microstructure Array And Its Electrical Properties

Biomedical electrodes which can convert ion potential of the human body into external electron potential are widely used in medical researches and clinical applications,including electrocardiogram(ECG),electromyogram(EMG),electroencephalogram(EEG)and bioelectrical impedance(EIT),etc.Conventional Ag/AgCl wet electrodes have the advantage of stable signal baseline,but the conductive gel will gradually dry up,even cause allergic phenomenon,resulting in its not suitable for long-time measurement and monitoring of bioelectric signals.In this paper,laser milling-recasting technology was proposed to fabricate medical metal dry electrodes with characteristics of surface microstructure arrays.The main work is as follows:1.Metal electrode cores with conical microstructure arrays were successfully developed by laser milling-recasting technology,and the metal dry electrodes were obtained after packaging.Based on the analysis of surface microstructural forming principle,the influences of processing parameters on microstructures were studied,and got the best processing parameters.The developed electrode cores had good mechanical strength and biocompatibility.2.The electrode-skin contact model was established to study the impedance performance of metal dry electrodes.This paper focused on the influences of electrode parameters(diameter of electrodes and laser processing parameters)and test conditions on the contact impedance,and obtained the optimal electrode parameters and the best test conditions.Compared with Ag/AgCl electrodes,the developed metal dry electrodes showed good impedance stability.3.The surface EMG signal and ECG signal were collected by metal dry electrode,and the bioelectrical signal was analyzed.Based on the principle of detection of surface EMG signal,the effects of electrode parameters(diameter of electrodes and laser processing parameters),different actions,different loads and different parts of muscle on EMG signals were studied.Compared with the Ag/AgCl electrodes,the electrical signal collected by the metal dry electrode had a larger amplitude.The electrocardiogram collected by the metal dry electrode was close to the Ag/AgCl electrodes,showing a clear ECG waveform.4.Surface treatment technologies including electroplating technology and anodizing technology were utilized to develop silver-plated metal dry electrodes and silver/silver chloride coating metal dry electrodes,respectively.These electrodes after treating presented a smaller contact impedance.Metal dry electrodes with super-hydrophobic surface were obtained after modifying by stearic acid ethanol solution,which could achieve exclusion of sweat during the acquisition of bioelectric signal.The developed metal dry electrodes have good impedance stability,which can obtain high-precision EMG,ECG and other bioelectric signals.These electrodes do not require time-consuming cuticle treatment,can avoid the occurrence of skin allergies,and have broad application prospects in the collection and utilization of bioelectricity.