Preparation Of Thermoplastic Polyurethane Composite Fiber Membrane And Its Deformation And Humidity Sensing Performance Study

Wearable flexible multifunctional sensors offer promising applications in motion monitoring and health management.Multifunctional wearable sensors based on electrostatic spun fiber membranes have the advantages of low cost,a simple process,and controllable composition.However,designing and fabricating multifunctional sensors with a wide operating range,low detection limits,high stability,and self-powering is still a challenging task.By compounding inorganic nanomaterials with thermoplastic polyurethane（TPU）materials and optimizing the components and structure,synergy and modulation of properties based on flexibility and elasticity can be achieved,resulting in multifunctional sensors with excellent performance.The specific contents of the paper include:（1）The design,preparation,and application of wearable flexible multifunctional sensors.A brush-like AgNPs@CNTs@TPU composite fiber membrane was constructed using a UV irradiation method to prepare carbon nanotubes（AgNPs@CNTs）modified with nanosilver particles,followed by depositing AgNPs@CNTs on the surface of TPU fiber membrane prepared by electrostatic spinning process through a cell crushing-ultrasonic assisted method.Based on the lapped conductive network formed by AgNPs@CNTs,a bifunctional sensor based on AgNPs@CNTs@TPU composite fiber membrane for strain and humidity was designed.As a strain sensor,the composite fiber membrane has an ultra-low detection limit（0.05%）,an ultra-wide sensing range of 600%,and excellent stability（100,000cycles,at 50%strain）.As a humidity sensor,the composite fiber membrane can achieve a fast response time of 1 second.The superior performance comes from the sensitive response of the lapped network during environmental changes.With excellent sensing capabilities in strain and humidity,the fiber membranes can be used to monitor respiration,pulse and limb movement,as well as non-contact sound sensing.（2）Designing,preparing,and applying the triboelectric nanogenerator（TENG）.We prepared Ta₂O₅@TPU（TT）composite fiber membranes and PVDF-PMMA（PP）composite fiber membranes using the electrostatic spinning method.These membranes were used as the positive and negative electrodes of the TENG,respectively.The ester functional group can act as a charge transfer site,which enhances the charge trapping ability of PVDF.By introducing Ta₂O₅ and PMMA,we effectively enhance the positive charge of the TPU fibers and the mechanical properties of PVDF,respectively.The ester functional groups of PMMA can serve as transition sites for transporting captured charges,effectively enhancing the charge capture ability of PVDF.The TENG（TTPPT）,composed of TT and PP,demonstrates excellent triboelectric output performance.The optimized TTPPT generates an open circuit voltage of 10μA,a short circuit current of 265 V,a response time of 24 ms,and a power density of 27.2 W/m² at an operating frequency of 5 Hz.This optimized TTPPT can detect water flow and efficiently collect water energy for real-time power generation.