| Flexible epidermal electronics is one of the most likely methods to be applied in clinical wearable monitoring devices among current bioinformatics detection technologies.Real-time monitoring of human physiological information requires long-term attachment of sensors to the skin.However,most of the substrates of wearable sensors are airtight films.Long-term attachment of such substrates to human skin will cause skin discomfort and lead to accumulation of tissue fluid,which will affect the detection results of the sensor.Materials like non-woven fabrics and paper are air permeable due to their porous structure.While these materials cannot withstand the high temperature during the sintering process of metal electrode,which limits their application.Based on these problems,we proposed the polyimide nanofiber films with high temperature resistance and good air permeability prepared by polyamic acid(PAA)using electrospinning.A thermostatic permeable flexible epidermal electrochemical glucose sensor is designed based on the permeable substrate,and the process of fabrication and integration of sensor by inkjet printing is studied.Finally,the thermostatic glucose detection is realized,which avoids the influence of environmental temperature changes.The following work has been completed:1.Processing and performance tests of breathable substrate: Surface morphology of the nanofiber membrane spun under different spinning voltages,flow rates,concentrations and distances are characterized by SEM,and the optimal spinning parameters are determined.Then the spinning time is determined based on the air permeability and mechanical properties of the membrane.Finally,the substrate with excellent air permeability and moisture permeability is processed.2.Processing and performance tests of glucose sensor: A flexible glucose sensor is designed and processed based on a permeable substrate.Graphene,platinum nanoparticles and Prussian blue are introduced to modify the working electrode surface to enhance the detection performance of the sensor.Finally GOx is used to realize the detection of glucose concentration within the physiological range.3.Processing and tests of heating wire and temperature sensor: Combined with the previous COMSOL simulation of skin structure in my group,the structure reconstruction of the double helix structure temperature sensor and heating wire is completed,and the feasibility of skin temperature control by heating wire and temperature sensor is verified through simulation.Then inkjet printing is used to fabricate heating wire and temperature sensor,and the temperature sensor is calibrated and tested.Finally,the skin surface heating and temperature control experiment is realized by PID control.4.Processing and tests of sensor patch: The sandwich structure of glucose sensor,polymer support layer and temperature control system is constructed.According to the requirements of adhesion between patch and skin,the flexible patch frame and wire layers are designed.Based on the requirements of the integration of the sensor and the detection equipment,a zero insertion force(ZIF)sensor interface is designed and the glucose detection experiment under constant temperature is completed based on the patch. |
