Design And Key Characteristics Of Dual-mode Electronic Skin For Human Physiological Information Detection

Electronic skin is an important emerging technology that can bring many potential benefits to people,such as playing a role in medical,security,human health monitoring,and other fields.With the continuous development of technology,electronic skin is becoming smaller and more intelligent,and has begun to have more complex sensors to detect external information,which has aroused widespread concern among researchers.However,most research is limited to the detection of a single signal and lacks the collection of multimodal information.Therefore,in order to achieve comprehensive application of electronic skin,it is necessary to build the e-skin that can detect multimodal information.For such e-skin,excellent performance is the first characteristic they need to possess,so the selection of materials for manufacturing e-skin needs to be very rigorous.In addition,obtaining high-performance e-skin through simple and inexpensive processing methods has become the direction of joint efforts by scholars.Based on the manufacturing of the aforementioned e-skin,the design and development of intelligent human health monitoring systems and related applications for wearable electronic devices are also key to research.In order to solve these challenges,this dissertation presents two dual mode flexible sensors with different functions,and the comprehensive applications related to temperature and humidity have been designed respectively.Through parallel work of hardware and software,a human physiological information monitoring system has been designed and implemented to detect and identify different states of the human body.The main research contents are as follows:（1）A dual mode flexible sensor with a multi-layer structure was proposed,which senses pressure and temperature information by integrating different sensing layers on both sides of the flexible substrate.The introduction of an elastic nanofiber framework and the internal"sea urchin"shaped conductive filler are important reasons for the excellent sensing performance and durability of sensors.The fabricated sensor ultimately exhibits a high pressure sensitivity of 111.96 k Pa^-1 over a wide sensing range of up to 70 k Pa,with a minimum detection limit of7 Pa and a fast response recovery time of 40 ms.As for temperature stimulation,the sensor achieves a high linear response to ambient temperature changes in the range of 20℃to 50℃,with a sensitivity of up to 2.23%℃^-1,and maintains high stability and durability after long-term bending cycles.In addition,by integrating sensors into intelligent temperature monitoring systems,it has shown great potential in non-contact dynamic temperature measurement.（2）Under different sensing mechanisms,a dual mode flexible sensor for pressure and humidity combining a triboelectric nanogenerator and a resistance sensing method was implemented.In terms of pressure sensing,based on the frictional electrification effect and the principle of electrostatic induction,the sensor has a sensitivity of 1 V k Pa^-1 and can work within a pressure range of 0-50 k Pa.And for humidity sensing,the excellent response ability of the sensor to humidity has been verified through testing various performance aspects such as humidity hysteresis curve,response recovery time,durability,and so on.Further,the sensor is combined with a commercial mask to meet the need for detecting the respiratory rate and state of the human body through the sensor.（3）Based on the dual mode flexible sensors implemented above,a new intelligent human physiological information detection system was designed and developed.Starting with the overall scheme of the system,the hardware circuits needed have been designed,using a signal acquisition circuit based on ADS1220 and an ESP32-PICO-D4 with a built-in Wi-Fi module to achieve a series of functions for human physiological information from acquisition to processing to transmission.Through the use and operation of software on intelligent terminal,human physiological information can ultimately be presented in the form of data and waveform changes.The system realizes the function of real-time detection of multiple physiological information of the human body through the coordination and joint work of multiple sensors,and has broad prospects in future medical and health monitoring.The research shows that the proposed dual mode electronic skin provides a new strategy for electronic devices dedicated to sensing external information,and has unlimited potential in flexible electronics,artificial intelligence,and human-machine interaction.