MXene/TPU Composite Film for Humidity Sensing and Human Respiration Monitoring

Abstract

Human respiration reflects abundant physiological information and could enable non‐invasive monitoring, providing information about various biological parameters such as respiration rate and depth. The rapidly growing field of humidity sensors bring forward the requirement for good performance. In this work, by virtue of good hydrophilicity and conductivity, a MXene/thermoplastic polyurethane (TPU) composite film is prepared by coating MXene nanosheets on chitosan‐modified TPU electrospun nanofibers via electrostatic interactions, for fabricating a humidity sensor. Based on the principle that the tunnel resistance changing with water molecules influences the distance of MXene nanosheets, the MXene/TPU humidity sensor exhibits fast response (12 s), wide humidity response range (11–94% RH), low hysteresis (<7% RH), and excellent repeatability. The humidity sensor can be assembled with a face mask for distinguishing different human respiration patterns and accurately monitoring respiratory signals during different physical activities, suggesting its promising applications in the fields of respiratory monitoring.

Electrically Conductive AgNPs/TPU-Electrospun Fibers with Hierarchical Microstructures by a One-Step Method for a High-Performance Flexible Pressure Sensor

“…The XRD pattern of the pristine TPU nanofiber film shows a broad peak around 2θ = 20°, indicating that TPU is a weakly crystalline polymer material. 16 For the C 2 AgF 3 O 2 /TPU nanofiber film, C 2 AgF 3 O 2 was well mixed with TPU, and the broad peak was well reserved without producing another crystalline phase. For the AgNPs/ TPU nanofiber film, the diffraction peaks at 2θ = 38.19, 44.36, 64.43, and 77.4°correspond to the characteristic peaks of the (111), ( 200), (220), and (311) planes of metallic Ag, respectively.…”

“…Figure k shows the XRD patterns of C 2 AgF 3 O 2 /TPU, AgNPs/TPU, and TPU nanofiber films. The XRD pattern of the pristine TPU nanofiber film shows a broad peak around 2θ = 20°, indicating that TPU is a weakly crystalline polymer material . For the C 2 AgF 3 O 2 /TPU nanofiber film, C 2 AgF 3 O 2 was well mixed with TPU, and the broad peak was well reserved without producing another crystalline phase.…”

“…Flexible pressure sensors typically consist of a flexible substrate, active materials, and electrodes . Commonly used flexible substrate materials include polydimethylsiloxane (PDMS), thermoplastic polyurethane (TPU), and poly(acrylic acid) hydrogel . Among them, the electrospun TPU nanofiber film has the advantages of high porosity, large surface area, and good air permeability, making it a candidate material for flexible substrates.…”

Temperature- and pressure-sensitive ionic conductive elastomer for respiratory monitoring and human motion sensing

“…Several illnesses are related to respiratory rate and depth, 3 such as obstructive sleep apnea syndrome, 4 pneumonia, 5 bronchitis, 6 and cardiovascular disorders. 7 Therefore, developing a respiration rate- and breath-monitoring device is crucial for human health assessments. Currently, effective respiratory monitoring equipment is used in intensive care units or operating rooms in hospitals.…”

Transient Flexible Multimodal Sensors Based on Degradable Fibrous Nanocomposite Mats for Monitoring Strain, Temperature, and Humidity

“…Recently, flexible multimodal sensors responsive to multiple stimuli (humidity, temperature, etc.) in addition to mechanical stimuli are increasingly being investigated. − However, most of the flexible devices are still based on nondegradable polymer materials. − E-waste has enormous environmental pollution risks similar to traditional polymer materials and e-waste pollution of conventional inorganic electronic devices. − Therefore, the development of green flexible devices utilizing degradable materials has been an urgent subject.…”