posted on 2022-09-30, 10:06authored byTianxue Zhu, Yimeng Ni, Kaiying Zhao, Jianying Huang, Yan Cheng, Mingzheng Ge, Cheolmin Park, Yuekun Lai
Wearable strain sensors have aroused increasing interest
in human
motion monitoring, even for the detection of small physiological signals
such as joint movement and pulse. Stable monitoring of underwater
human motion for a long time is still a notable challenge, as electronic
devices can lose their effectiveness in a wet environment. In this
study, a superhydrophobic and conductive knitted polyester fabric-based
strain sensor was fabricated via dip coating of graphene oxide and
polydimethylsiloxane micro/nanoparticles. The water contact angle
of the obtained sample was 156°, which was retained above 150°
under deformation (stretched to twice the original length or bent
to 80°). Additionally, the sample exhibited satisfactory mechanical
stability in terms of superhydrophobicity and conductivity after 300
abrasion cycles and 20 accelerated washing cycles. In terms of sensing
performance, the strain sensor showed a rapid and obvious response
to different deformations such as water vibration, underwater finger
bending, and droplet shock. With the good combination of superhydrophobicity
and conductivity, as well as the wearability and stretchability of
the knitted polyester fabric, this wireless strain sensor connected
with Bluetooth can allow for the remote monitoring of water sports,
e.g., swimming, and can raise an alert under drowning conditions.