posted on 2019-05-16, 00:00authored byYang Lu, Zhongqi Liu, Haoming Yan, Qing Peng, Ruigang Wang, Mark E. Barkey, Ju-Won Jeon, Evan K. Wujcik
Wearable strain sensors
are essential for the realization of applications
in the broad fields of remote healthcare monitoring, soft robots,
and immersive gaming, among many others. These flexible sensors should
be comfortably adhered to the skin and capable of monitoring human
motions with high accuracy, as well as exhibiting excellent durability.
However, it is challenging to develop electronic materials that possess
the properties of skincompliant, elastic, stretchable, and
self-healable. This work demonstrates a new regenerative polymer complex
composed of poly(2-acrylamido-2-methyl-1-propanesulfonic acid), polyaniline,
and phytic acid as a skin-like electronic material. It exhibits ultrahigh
stretchability (1935%), repeatable autonomous self-healing ability
(repeating healing efficiency >98%), quadratic response to strain
(R2 > 0.9998), and linear response
to
flexion bending (R2 > 0.9994), outperforming
current reported wearable strain sensors. The deprotonated polyelectrolyte,
multivalent anion, and doped conductive polymer, under ambient conditions,
synergistically construct a regenerative dynamic network of polymer
complex cross-linked by hydrogen bonds and electrostatic interactions,
which enables ultrahigh stretchability and repeatable self-healing.
Sensitive strain-responsive geometric and piezoresistive mechanisms
of the material owing to the homogeneous and viscoelastic nature provide
excellent linear responses to omnidirectional tensile strain and bending
deformations. Furthermore, this material is scalable and simple to
process in an environmentally friendly manner, paving the way for
the next-generation flexible electronics.