This review summarizes the recent developments and importance of wearable electronic textiles in the past decade. Wearable electronic textiles are an emerging interdisciplinary research area that requires new design approaches. This challenging interdisciplinary research field brings together specialists in electronics, information technology, microsystems, and textiles to make an innovation in the development of wearable electronic products. Wearable electronic textiles play a key role among various technologies (clothing, communication, information, healthcare monitoring, military, sensors, magnetic shielding, etc.). In this review, applications of wearable electronic textiles are described, including an investigation of their fabrication techniques. This review highlights the basic processes, possible applications, and main materials to build wearable E‐textiles and combines the fundamentals of E‐textiles for the readers who have different backgrounds. Moreover, reliability, reusability, and efficiency of wearable electronic textiles are discussed together with the opportunities and drawbacks of the wearable E‐textiles that are addressed in this review article.

The presented work focused on the development of temperature sensors based on specially formulated carbon nanotube (CNT) and poly(3,4-ethylene dioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) based inks which are deposited directly onto the adhesive polyamide-based taffeta fabric with low-cost office-type inkjet printer. Stable and uniform dispersions of CNT and PEDOT:PSS with Triton X-100 were formulated to be used as temperature sensitive inkjet inks. Three kinds of temperature sensors were fabricated using sensitive materials including CNT ink, PEDOT:PSS ink, and CNT/PEDOT:PSS composite ink. Developed sensors are connected to the measuring devices via silver yarns and silver adhesive paste. Sensors are covered with translucent polyurethane welding tape for packaging and protection. All the sensors exhibit negative temperature coefficient (NTC) behavior and sensitivity of 0.15 %/°C for CNT, 0.41 %/°C for PEDOT:PSS, and 0.31 %/°C for CNT/PEDOT:PSS for temperatures varying from room temperature to 50 °C. CNT/PEDOT:PSS composite ink printed sensor achieved better sensing repeatability and demonstrated higher bending stability with a resistance change of 0.3 % up to 1000 cycles than CNT printed and PEDOT:PSS printed sensors. The softness, lightness, and capability to work on flexible or curved surfaces make the developed CNT/PEDOT:PSS composite ink printed sensor a robust candidate for wearable temperature sensor applications, especially in situations requiring continuous body temperature monitoring while satisfying comfort of the user.

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.