Research On Flexible Micro-Nano Sensor For Weak Mechanical Signal Detection

The accelerated pace of life and the unhealthy lifestyle of modern people have led to a gradual increase in the incidence of cardiovascular diseases（CVDs）（including cardiomyopathy,coronary heart disease,hypertension,etc.）,and the affected population tends to be younger.And with the aging of the global population,cardiovascular disease has become the disease with the highest mortality rate in the world.The severity of the disease and the consequent risks are also prompting people to pay more attention to their cardiovascular health.Therefore,there is an urgent need for a simple,easy-to-operate,and long-term real-time monitoring method for cardiovascular health.to reduce the risk of cardiovascular disease.Compared with large-scale ECG detection equipment in traditional hospitals,wearable flexible sensors have gradually attracted widespread attention due to their advantages of portability,long-term real-time monitoring and low cost.Based on the above background,this subject designed and fabricated a flexible sensor based on carbon materials and high molecular polymer composite materials to detect human physiological signals to assess physical health.The details are as follows:In this study,a zinc nanoparticle-modified sandwich sensor was prepared.The device prepared by using zinc nanoparticles to modify the interlayer has a large strain response range（0-25%）and high sensitivity（GF=31.63）,and its maximum pressure sensitivity can reach 7.88×10^-3k Pa^-1k Pa^-1,and shows good Durability（>5000 pressure load/release cycles）and repeatability（96.71%sensitivity retention after 5000 cycles）.In addition,the sensor also shows great potential in health detection.The sensor can be used to detect real-time pulse signals in different exercise states to evaluate human cardiovascular health.situation.Therefore,the sensor can play an important role in predicting cardiovascular health status in advance and reducing the current high incidence of cardiovascular disease.In addition,an electric field-aligned CNT-GR/PDMS hybrid composite sensor was prepared in this study.The preparation process of the dry mixing method is improved through two steps,the preparation process is non-toxic,and the key detection performance of the sensor is retained at the same time,which can be used as a high-sensitivity sensor for safely detecting human health signals.In the design of this sensor,we improved the performance of the device in two steps:（a）CNT-GR/PDMS hybrid composites were fabricated by doping CNTs in the GR/PDMS prepared by the traditional dry-mixing method（b）in the During the preparation of CNT-GR/PDMS,a 4×10⁵V/m sinusoidal AC electric field with a frequency of 10 k Hz and a 4×10⁵V/m composite electric field with a frequency of 10 k Hz+1 k Hz were respectively applied to prepare the CNT-GR/PDMS hybrid composite material arranged in the electric field..Through the above optimization methods,the electrical properties,mechanical properties and detection performance of CNT-GR/PDMS hybrid composite devices arranged by applying a 4×10⁵V/m 10 k Hz+1 k Hz electric field have been greatly improved,and the electrical conductivity has been increased to 0.42 S/m;Young’s modulus increased to 2.38 MPa,tensile strength increased to 0.81 MPa,elongation at break increased to 120%;strain detection range increased to 25%,sensitivity GF increased to 307.Finally,the sensor prepared in this topic is used for human health monitoring.The experimental results prove that it has high sensitivity,high detection range and high biocompatibility as a health detection sensor,and also shows excellent performance in the detection of weak mechanical signals in the human body.