| The rapid development of the Internet of Things and wearable devices provides an effective method for human health monitoring.Wearable devices that can detect sweat,blood sugar,pulse,respiration,heart rate and other health indicators have aroused widespread interest.However,continuous data acquisition,processing and wireless transmission put forward higher requirements for the power supply.The traditional power supply mode based on power grid and battery has been difficult to meet its requirements of lightweight,convenient,wireless and environmental protection.Constructing self-powered system is an important research direction to further develop health monitoring devices and solve energy supply problems.The self-powered system harvest energy from the surrounding environment through energy harvesting technology,and realizes sensing,data processing and transmission without the need for external power supply.Considering the application scenarios of sweat sensing devices,it is an ideal energy solution to convert the mechanical energy of human motion into electrical energy for the operation of sweat sensing systems.Triboelectric nanogenerator(TENG)is a new energy harvesting and information sensing technology.It not only can effectively harvest the mechanical energy of human motion,but also can be directly used as an active sensor,which is a logical choice for constructing self-powered systems.This paper aims to combine TENG technology and health monitoring to construct a wearable/portable wireless health monitoring system,and conduct research on many aspects such as human motion energy harvesting,information sensing,energy management and system integration based on TENG technology.The research points of this paper are as follows:(1)A tribo-electromagnetic hybrid nanogenerator(HNGM)was fabricated by spring-mass coupled mechanical design.The hybrid nanogenerator can harvest energy from vibrations generated by human movement.HNGM can be used as an energy harvesting module for parallel use.Based on this,a wearable wireless self-powered sweat analysis system(SWSAS)was designed.Real-time on-body sweat analysis powered by HNGMs demonstrated that SWSAS selectively sensing biomarkers(Na~+and K~+)in sweat and wirelessly transmits the sensing data to a user interface via Bluetooth.This work realizes wireless sweat detection completely driven by motion energy,which has great application potential in the field of personalized health detection.(2)To further improve the overall output power of the device,a fitness gyroscope nanogenerator(fg-NG)with frequency conversion effect is proposed.Using the precession effect of the gyroscope,the low-frequency movement of the wrist is converted into the high-frequency rotation of the flywheel.Under manual driving,the fg-NG can reach a speed of more than 8000 rpm,and the output frequency is increased by more than 280 times.Wireless sweat sensing system powered by fg-HG for simultaneous monitoring of Na~+,K~+and glucose concentrations in sweat,as well as sweat p H,while increasing the sampling rate of data.This work not only proposes a strategy to effectively obtain the low-frequency motion mechanical energy of the human body through the frequency up-conversion effect,but also provides a reliable and universal power supply unit for wearable electronic devices and wireless Io T devices.(3)Inspired by the structure of shark gill,a self-powered,multi-channel respiration sensor was constructed.The bionic shark gill structure can transform the transverse elastic deformation during stretching into longitudinal elastic deformation.Combining the optimized biomimetic shark gill structure with piezoelectric and triboelectric effects,the biomimetic shark gill respiration sensor(BSG-RS)can generate graded electrical responses to different tensile strains.Based on this feature,BSG-RS can simultaneously and accurately detect the respiratory rate and inhalation depth,and realize the effective identification of different human breathing states under the auxiliary software. |
PDF Full Text Request