Prearation And Application Of New Flexible Wearable Sensors

In recent years,with the continuous advancement of the Internet,wireless technology and flexible electronics,various new flexible wearable sensors have been widely used.According to the current research status of flexible sensors,this paper mainly constructs flexible,degradable pressure sensors with ultra-high sensitivity and fast response and flexible humidity sensors with good stability.The detailed work is as follows:1.A pressure sensor was fabricated by sandwiching MXene-impregnated porous tissue paper between a biodegradable polylactic acid(PLA)sheet and an interdigitated electrode coated PLA sheet.The influences of MXene concentration,encapsulation layer thickness,and different tissue types on the performances of the pressure-sensitive sensor were investigated.The as-prepared pressure sensor is then attached the detection of to the human body for pulse,swallowing,chewing and other motions.The results demonstrated that the pressure sensor possessed high sensitivity,wide detection range(10.2 Pa-30 kPa),fast response capability(11 ms)and excellent reproducibility of more than 10000 cycles.Furthermore,the pressure sensor could be assembled into an electronic skin for real time spatial tactile stimuli mapping and wirelessly data transmission.Moreover,the in vitro degradation and cytotoxic evaluation confirmed that the sensor was biodegradable and biocompatible,which further highlighted the great potential of this pressure sensor applied for healthcare monitoring,human-machine interaction,medical diagnosis and electronic skin.2.Secondly,the interdigital electrode was screen printed on the flexible polyethylene terephthalate(PET)substrate,followed by the brush coating of liquid exfoliated black phosphorus(BP)on the surface of the electrode to prepare a flexible and wearable humidity sensor.The operating frequency,impedance variation at 11%-95%humidity,response and recovery time of the as-prepared humidity sensor were investigated.The results indicated that the humidity sensor has a large order of magnitude resistance change(three orders of magnitude),fast response capability(12 s)and short recovery time(37 s).Besides,the humidity sensor exhibited excellent performance stability at different bend radii.In addition,the humid sensitive device can be used to detect the respiratory frequency and respiratory intensity of the human body before and after exercise.Furthermore,the sensing data can be wirelessly transmitted to a mobile phone in real time through a Bluetooth connection,which confirmed the applicability of the humidity sensor to be used for healthcare monitoring such as apnea syndrome.