Conductive hydrogel-based ionic skins have attracted
immense attention
due to their great application prospects in wearable electronic devices.
However, simultaneously achieving a combination of a single hydrogel
system and excellent comprehensive performance (i.e., mechanical durability,
electrical sensitivity, broad-spectrum antibacterial activity, and
biocompatibility) remains a challenge. Thus, a novel poly(ionic liquid)
hydrogel consisting of poly(acrylamide-co-lauryl
methacrylate-co-methyl-uracil-imidazolium chloride-co-2-acryloylamino-2-methyl-1-propane sulfonic acid) (AAm-LMA-MUI-AMPS)
was prepared by a micellar copolymerization method. Herein, MUI serves
as a supramolecular crosslinker and conductive and bacteriostatic
components. Owing to the multiple supramolecular crosslinks and hydrophobic
association in the network, the hydrogel exhibits excellent mechanical
properties (624 kPa of breaking stress and 1243 kPa of compression
stress), skin-like modulus (46.2 kPa), stretchability (1803%), and
mechanical durability (200 cycles under 500% strain can be completely
recovered). Moreover, with the coordinated combination of each monomer,
the hydrogel exhibits the unique advantage of high conductivity (up
to 59.34 mS/cm). Hence, the hydrogel was further assembled as an ionic
skin sensor, which exhibited a gauge factor (GF) of 10.74 and 7.27
with and without LiCl over a broad strain range (1–1000%),
respectively. Furthermore, the hydrogel sensor could monitor human
movement in different strain ranges, including body movement and vocal
cord vibration. In addition, the antibacterial activity and biocompatibility
of the hydrogel sensor were investigated. These findings present a
new strategy for the design of new-generation wearable devices with
multiple functions.