Research On Multifunctional Dry Electrodes And Clothing For Synchronous Pressure-ECG Acquisitio

The microstructured surfaces of bioelectrical dry electrodes are important aspects of dry electrode design.However,traditional surfaces for microstructured bioelectrical dry electrodes are costly to produce and require complex fabrication methods,and the existing dry electrodes cannot recognize the pressure fluctuation on the skin surface.This thesis proposes a simple and low-cost"stacked template"method and integrated a flexible pressure sensor on the back of the electrode to develop Fructus Xanthii-inspired barb structure（FXbs）dry electrode for simultaneous acquisition of pressure and bioelectricity,and makes a pressure-bioelectricity simultaneous acquisition multifunctional garment.First,a new method of microstructure electrode preparation by"stacked template"is proposed,and three sizes of microstructured Ag/AgCl thermoplastic polyurethane（TPU）electrodes with a Fructus Xanthii-inspired barb structure（FXbs）are prepared using this method.The effect of electrode structure on its dynamic friction performance,electrical performance,and hair interference resistance is investigated under different pressure and speed,and the electrochemical performance and ECG signal acquisition performance of the electrodes are systematically studied on the human skin surface and in the simulated environment,respectively.The dynamic friction coefficient of the microstructured electrode is improved by 38.8%,and it can maintain stable electrical contact under the interference of 9 hairs,and the impedance in the low-frequency region is reduced by 76.9%after chlorination treatment,and the signal-to-noise ratio in the swing arm condition is 27.77 dB,which is suitable for dynamic measurements.In addition,the peak time deviation and voltage attenuation amplitude of the collected signal is low and comparable to those of the wet electrode when the test is performed with simulated instruments.Then,three sizes of conical anodic aluminum oxide（C-AAO）templates are prepared using electrochemical anodization,and a regularized micro-nanocone polyaniline/polymethyl methacrylate（PANI/PMMA）flexible conductive film is prepared by in situ polymerization and spin-coating methods.The flexible sensor is prepared by an interlocking package,and the micro-nanocone length of 1.38μm has the best sensing performance.The sensor exhibits a high sensitivity of 108.27 kPa^-1,cyclic stability at 2000 loadings,and low hysteresis of±4.72%in the range of 0-2.3kPa,and can accurately monitor finger flexion angle,wrist motion status,and body motion status.Finally,a multifunctional sensor for simultaneous pressure-ECG acquisition is prepared by printing a circuit on the back of the Ag/AgCl-TPU electrode and encapsulating a PANI/PMMA flexible piezoresistive sensor on the back of the electrode,and an ECG monitoring garment for simultaneous acquisition of pressure and ECG is fabricated by integrating the multifunctional sensor into a tight-fitting garment using a hot pressing process.The test results showed that the fluctuation range of ECG is 0.99m V when the change rate of piezoresistance reaches 51.41%,and 1.61 m V when the pressure loading rate is 0.5 mm/s.The fluctuation range of ECG is 5.99 m V when the change rate of resistance reaches 5.02%under the turning condition.The multifunctional ECG monitoring suit with simultaneous pressure and bioelectricity monitoring is prepared in this thesis,and this ECG monitoring suit can provide experimental methods and a theoretical basis for studying the dynamic noise mechanism of microstructured surface electrode/electrolyte interface.