posted on 2022-10-31, 17:05authored byZhaolong Wang, Haoyong Song, Lei Chen, Wenhao Li, Dongsheng Yang, Ping Cheng, Huigao Duan
Ionic
hydrogels are conductive and stretchable, showing
great potential
for applications in flexible wearable devices. However, poor mechanical
and electrical properties, low manufacturing precision, and lack of
self-adhesion severely limit their practical applications in hydrogel
wearable devices. Herein, we propose a stretchable, highly conductive,
and self-adhesive ionic hydrogel fabricated with an LCD light-curing
3D printing technique. 2-Acrylamido-2-methylpropane sulfonic acid
(AMPS), 4-hydroxybutyl acrylate (HBA), and graphene are incorporated
to prepare the printable ion-conductive hydrogel. The results show
that this hydrogel exhibits outstanding electrical conductivity (0.0487
S/cm), excellent linear sensitivity (GF = 1.86 within 100% strain),
amazing stretchability (1200% strain), and strong adhesion performance
with various materials. Furthermore, the HBA–AMPS–graphene
(HAG) hydrogel-based flexible wearable devices can monitor various
human movements from tiny scale (breathing and speaking) to large
scale (such as elbow and knee joint movement). Most significantly,
the hydrogel wearable devices can capture the signals of pulse beating
and breathing, which are so light that they are hard to be monitored.
Our printable ionized hydrogel wearable devices promise applications
in motion monitoring, health detection, human–machine interface,
and so on.