posted on 2021-10-23, 15:43authored byJianwen Chen, Fei Wang, Guoxuan Zhu, Chengbao Wang, Xihua Cui, Man Xi, Xiaohua Chang, Yutian Zhu
Wearable strain and temperature sensors
are desired for human–machine
interfaces, health monitoring, and human motion monitoring. Herein,
the fibrous mat with aligned nanofibers of ionic liquid (IL)/thermoplastic
polyurethane (TPU) ionogels is fabricated via an electrospinning technique.
The resultant fibrous mat is cut into a rectangle specimen and electrodes
are loaded along the direction perpendicular to the nanofiber orientation
to design a high-performance multimodal sensor based on an ionic conducting
mechanism. As a strain sensor, the obtained sensor exhibits a wide
strain working range (0–200%), a fast response and recovery
(119 ms), a low detection limit (0.1%), and good reproducibility because
of the reversible and deformable ionic conductive pathways of the
sensor. Moreover, the sensor also exhibits excellent temperature-sensing
behaviors, including a monotonic thermal response, high sensitivity
(2.75% °C–1), high accuracy (0.1 °C),
a fast response time (2.46 s), and remarkable repeatability, attributable
to the negative temperature coefficient behavior of the IL/TPU fibrous
mat. More interestingly, the IL/TPU fibrous sensor possesses good
breathability, which is desired for wearable electronics. Because
of these excellent sensing capabilities in strain and temperature,
the sensor can not only monitor tiny and large human motions but also
detect respiration and proximity, exhibiting enormous potential in
wearable electronics.