Bioinspired Fluffy Fabric with In Situ Grown Carbon Nanotubes for Ultrasensitive Wearable Airflow Sensor

Abstract

Recently, electronic skin and smart textiles have attracted considerable attention. Flexible sensors, as a kind of indispensable components of flexible electronics, have been extensively studied. However, wearable airflow sensors capable of monitoring the environment airflow in real time are rarely reported. Herein, by mimicking the spider's fluff, an ultrasensitive and flexible all‐textile airflow sensor based on fabric with in situ grown carbon nanotubes (CNTs) is developed. The fabric decorated with fluffy‐like CNTs possesses exceptionally large contact area, endowing the airflow sensor with superior properties including ultralow detection limit (≈0.05 m s−1), multiangle airflow differential response (0°–90°), and fast response time (≈1.3 s). Besides, the fluffy fabric airflow sensor can be combined with a pristine fabric airflow sensor to realize highly sensitive detection in a wide airflow range (0.05–7.0 m s−1). Its potential applications including transmitting information according to Morse code by blowing the sensors, monitoring increasing and decreasing airflow velocity, and alerting blind people walking outside about potential hazard induced by nearby fast‐moving objects are demonstrated. Furthermore, the airflow sensor can be directly integrated into clothing as stylish designs without sacrificing comfortness. It is believed that the ultrasensitive all‐textile airflow sensor holds great promise for applications in smart textiles and wearable electronics.

Band Engineering of Carbon Nanotubes for Device Applications

“…Zhang's group reported a series of flexible fibers based on CNTs, silk composites, which can be further weaved into sensors and supercapacitors. [162][163][164] CNT-based aerogels, which are usually obtained in sol-gel processes, mixed with specific polymers/binders, 165 or grafted with functional groups, can serve as conductive additives in electrode materials for supercapacitors, 166 providing a large specific surface area for a high energy density and interconnected conductive networks for fast charging/discharging processes. CNT sponges, which can be directly synthesized using CVD methods, can be used as additives in Li-ion batteries 167 or solid-state fluoride-ion batteries (e.g., CaF 2 , MgF 2 ).…”

Electrostatic self-assembly enabled flexible paper-based humidity sensor with high sensitivity and superior durability

“…Humidity is one of the essential indexes of air, which is important for industrial and agricultural production and our daily life. As a humidity detection tool, flexible electronic humidity sensors have attracted much attention because of their wide applications in fields of wearable electronics, smart textiles, electronic skin, and soft robotics [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] . Specifically, conductive polymer composite-based humidity sensors with incorporated electrically conductive fillers in insulating polymer matrixes are attracting much attention owing to their excellent flexibility, low cost, and ease of processing [21] , [22] , [23] , [24] , [25] , [26] , [27] .…”

A Wearable, Bending-Insensitive Respiration Sensor Using Highly Oriented Carbon Nanotube Film

“…The airflow sensitivity was as high as 340 mV/(m/s) with the supplied current of 7 mA. This sensitivity was much higher than CNT thermal flow sensors reported previously [13], [26]. In addition, Figure 5b and Figure S2 show that the response time of the sensor (time lag taken to reach 90% magnitude of the signal) was less than 100 ms (bandwidth >10 Hz).…”

“…and G peak at 1579 cm −1 (sp 2 hybridization of crystalline carbon) [26]. Porous structure of the PAN nanofiber layers is illustrated in Figure 3e.…”