Disposable diapers are widely used by individuals with urinary incontinence. Diapers should be checked frequently for elderly, disabled, and hospital patients. Wet diapers that are not changed properly can cause health problems. The importance of electronic devices that provide warning in case of wetness is increasing in health monitoring. A disposable and wearable printed humidity sensor was designed and fabricated to detect wetness. The sensor was printed on polyamide-based taffeta label fabric by the inkjet printing method using specifically formulated PEDOT:PSS-based conductive polymer ink. The sensor sensitivity was tested under different relative humidity levels inside a controlled chamber. The resistance of the sensor decreased from 17.05 ± 0.05 MΩ to 2.09 ± 0.06 MΩ as the relative humidity increased from 35 to 100%, while the moisture value of the fabric increased from 4.8 to 23%. The response and recovery times were 42 s and 82 s. This sensor was integrated into the adult diaper to evaluate wetness. The sensor resistance change comparing to the dry state resistance (15.52 MΩ) was determined as 3.81 MΩ to 13.62 MΩ by dripping 0.1 mL to 100 mL salty water on the diaper. Due to its flexible structure and low-cost printability onto fabric, the wearable printed humidity sensor has the potential to be used as a disposable sensor for healthcare applications, particularly for urinary incontinence and capturing wetness in diapers.

In order to meet the increasing food demand, sensors that measure the ambient temperature and humidity in greenhouses are needed for more efficient vegetable and fruit production. For this purpose, two different flexible and resistant textile-based humidity sensors that can measure the humidity at higher levels (80%, 90%, and 100% relative humidity (RH)) were designed and printed directly on the four different greenhouse fabrics using silver and carbon conductive inks. Depending on the humidity value in the environment, the sensor performance was tested based on sensor electrical resistance measurements with respect to repeated bending/cyclic tests, rubbing, ultraviolet (UV) exposure/ weatherability (against UV and raining) tests in order to simulate greenhouse conditions for smart agriculture. Despite applying 1024 bending cycles, up to 20 rubbing cycles, and 10 times UV and rain exposure to the humidity sensors at high RH, no significant change was detected in the resistance values of the humidity sensors. Moreover, some important features of the sensors such as hysteresis, repeatability, response time have been also examined. According to hysteresis test results, humidity sensors show acceptable dynamic response and response time of the sensors are 15.8, 17.3, 24.8, and 25 s at 100% RH for G2S, W1S, B2C, and W1C, respectively. Statistical analyses showed that the sensor designs and type of conductive inks had significant effects on the performance of the humidity sensors and the best sensor performance was obtained with the polypropylene coated fabric using design II and silver based conductive ink. The fabricated textile based flexible humidity sensors detect the change in RH levels from 80% RH to 100% RH and achieve good durability, and repeatability even after prolonged UV exposure and raining. Thus, the developed textile-based flexible humidity sensor might be useful for future smart agricultural applications.

Nonwoven spunbonded polyester has wide applications for both household goods and home furnishings and their usage has continually been growing. Nowadays, coloration of nonwoven fabrics is performed using conventional methods. Conventional polyester dyeing is an energy-intensive process as the dyeing is carried out above 120 °C to obtain efficient diffusion of dye. Furthermore, these high temperatures may cause some harmful effects on delicate nonwoven structures. Ultrasound assisted textile dyeing is an alternative method of conventional dyeing of textile materials, providing energy saving by reduced process temperature and time, lower consumptions of auxiliaries with increased dyeing efficiency. This paper focuses on comparing the conventional (high temperature (HT) and carrier dyeing) and ultrasonic dyeing of nonwoven spunbonded polyester fabrics to investigate the effect of ultrasound energy on dyeing performance. Experimental results indicated that highest or comparable dyeing performance can be achieved with ultrasound dyeing at lower temperature (85 °C, 60 min.) without carrier as compared to carrier dyeing (100 °C, 60 min.) and HT dyeing (130 °C, 60 min.), providing an increase of dye depth depending on the dye concentration and basis weight of the fabric. It was evidently seen that highest basis weight of fabric (107 g/m²) used in this study exhibited greater color yield for each dye concentrations (K/S value of 4.90 at 0.2% dye concentration) as compared to conventional ones. The effect of ultrasound energy on reductive washing and fastness properties were also evaluated.

The use of wearable textile Radio Frequency Identification (RFID) sensors is becoming widespread in many different application areas because of their technical utilization advantages. In this study, a textile-based Ultra High Frequency (UHF) RFID sensor that can be used to detect wetness has been developed and fabricated with a pad printing machine using silver conductive ink. The overall physical dimension of the proposed sensor structure is 75.0 mm × 38.0 mm × 0.12 mm. Two different types of Received Signal Strength Indicator (RSSI) measurement setups in near field region and at practical separation distances emulating more realistic environmental conditions have been carried out to test and validate the applicability of the proposed sensor. Water, saline and urine solutions have been used to evaluate different wetting conditions in the near field RSSI measurements by dropping different solutions on the RFID sensor integrated diaper. A permissible signal difference of at least 17 dBm has been detected between the wet and dry states of the proposed wetness detection sensor. The performance of the proposed RFID sensor has been evaluated using different separation distances of 32 cm, 40 cm and 50 cm with the practical result of maximum reading range to be 50 cm for the reliable determination of the binary wetness states. In addition, the performance of the RFID wetness sensor against different bending and deformation conditions is almost robust. It is concluded that the proposed sensor structure can be integrated onto the patient’s diapers to facilitate the reliable detection of wetness states in cases such as urinary incontinence in remote health monitoring systems.

In this study, PEDOT:PSS conductive polymer printed flexible humidity sensor has been designed and fabricated to sense human respiration monitoring. PEDOT:PSS with conductive ink specifically formulated in our study, was printed on polyamide-based taffeta label fabric by an inkjet printing method. The sensitivity of the printed humidity sensor has been tested under different humidity levels inside a humidity chamber. Then, the sensor has been integrated into a face mask in order to evaluate the respiration monitoring of a user who wears the face mask in a real environment. The sensing capability of the wearable sensor and its response against respiration monitoring was evaluated under various breathing conditions such as fast and deep breathing, differentiating nose and mouth breathing. Owing to its flexible structure and printability onto textile, the wearable printed humidity sensor has the potential to be used for healthcare applications particularly for capturing user biomedical data.