The drive to enhance the operational
durability and reliability
of stretchable and wearable electronic and electrochemical devices
has led to the exploration of self-healing materials that can recover
from both physical and functional failures. In the present study,
we fabricated a self-healable solid polymer electrolyte, referred
to as an ionogel, using reversible hydrogen bonding between the ureidopyrimidone
units of a block copolymer (BCP) network swollen in an ionic liquid
(IL). The BCP consisted of poly(styrene-b-(methyl
acrylate-r-ureidopyrimidone methacrylate)) [poly(S-b-(MA-r-UPyMA)], with the IL-phobic polystyrene
forming micellar cores that were interconnected via intercorona hydrogen
bonding between the ureidopyrimidone units. By precisely regulating
the molecular weight and the composition of the hydrogen-bondable
motifs, the mechanical, electrical, and self-healing characteristics
of the ionogel were systematically evaluated. The resulting ionogel
samples exhibited suitable stretchability, ionic conductivity, and
room-temperature self-healability due to reversible hydrogen bonding.
To highlight the applicability of the self-healing ionogel as a high-capacitance
gate insulator, an electrolyte-gated transistor (EGT) was fabricated
using a poly(3-hexylthiophene-2,5-diyl) semiconductor, and the performance
of the EGT was fully recovered from a complete cut without any external
stimuli.