![Schematic diagram of the structure and applications of ion‐gel fibrous membrane. a) Schematic illustration of the ion‐gel fibrous membrane. b) Chemical structures of P(VDF‐HFP) and [EMIM][TFSI]. c) Photograph of the ion‐gel fibrous membrane fabricated via electrospinning. d–f) Corresponding optical microscopy images of the electrospun ion‐gel fibrous membranes with different ionic liquid concentrations (20, 33, and 50 wt.%). Insets are magnified images. Scale bar is 100 µm. g) Schematic diagram of iontronic capacitive sensor and TENG devices based on versatile ion‐gel fibrous membrane.](https://www.researchgate.net/publication/370764484/figure/fig1/AS:11431281188306425@1694571918689/Schematic-diagram-of-the-structure-and-applications-of-ion-gel-fibrous-membrane-a_Q320.jpg)
A preview of this full-text is provided by Wiley.
Content available from Advanced Functional Materials
This content is subject to copyright. Terms and conditions apply.
RESEARCH ARTICLE
www.afm-journal.de
Versatile Ion-Gel Fibrous Membrane for Energy-Harvesting
Iontronic Skin
Yang Liu, Chunlin Zhao, Yao Xiong, Jiahong Yang, Haishuang Jiao, Qian Zhang, Ran Cao,
Zhong Lin Wang,* and Qijun Sun*
Developing versatile and high sensitivity sensors is beneficial for promoting
flexible electronic devices and human-machine interactive systems.
Researchers are working on the exploration of various active sensing
materials toward broad detection, multifunction, and low-power
consumption. Here, a versatile ion-gel fibrous membrane is presented by
electrospinning technology and utilized to construct capacitive sensors and
triboelectric nanogenerator (TENG). The iontronic capacitive sensor exhibits
inherently favorable sensitivity and repeatability, which retains long-term
stability after 5000 cycles. The capacitive sensor can also detect a clear pulse
waveform at the human wrist and enable the mapping of pressure
distribution by a capacitive sensory matrix. For the iontronic TENG, the
maximum peak power is 54.56 μW and can be used to power commercial
electronics. In addition, the prepared iontronic TENG array can achieve
interactive, rapidly responsive, and accurate dynamic monitoring, which
broadens the exploration to direct and effective sensory devices. The versatile
ion-gel fibrous membrane is promising to provide an outstanding approach
for physiological detection, biomechanical energy harvesting, human-machine
interaction, and self-powered monitoring systems.
Y. Liu, H. Jiao, Q. Sun
Center on Nanoenergy Research, School of Physical Science and
Technology
Guangxi University
Nanning 530004, P. R. China
E-mail: sunqijun@binn.cas.cn
Y.Liu,C.Zhao,Y.Xiong,J.Yang,H.Jiao,Q.Zhang,R.Cao,Z.L.Wang,
Q. Sun
Beijing Institute of Nanoenergy and Nanosystems
Chinese Academy of Sciences
Beijing 101400, P. R. China
E-mail: zhong.wang@mse.gatech.edu
R. Cao
State Key Laboratory for Modification of Chemical Fibers and Polymer
Materials, College of Materials Science and Engineering
Donghua University
Shanghai 201620, P. R. China
Z. L. Wang
Georgia Institute of Technology
Atlanta, Georgia 30332-0245, USA
Q. Sun
Shandong Zhongke Naneng Energy Technology Co., Ltd.
Dongying 257061, P. R. China
The ORCID identification number(s) for the author(s) of this article
can be found under https://doi.org/10.1002/adfm.202303723
DOI: 10.1002/adfm.202303723
1. Introduction
In recent years, flexible sensors have
been widely used in various advanced
devices, such as electronic skin,[1–5]
touch sensors,[6–10 ] electronic flexible
fabrics,[11–13 ] medical assisted monitoring
equipment,[14–17 ] and so on. Specifically,
the researches on machine-learning-
motivated electronic skin have emerged
for developing more intelligent percep-
tion system,[15,18 ] which have made an
important exploration for the development
of electronic skin and strongly promoted
the practical intelligent perception tech-
nology. Highly sensitive flexible pressure
sensors are essential to achieve sensitive
and effective detection. Through improve-
ments in the selection and preparation of
materials, the shape and performance of
flexible pressure sensors have been greatly
improved. Commonly utilized sensors
include resistive,[19–22 ] capacitive,[23–28 ]
piezoelectric,[29–32 ] and triboelectric[33–36 ]
types, etc. All these types of sensors functionalize by converting
external stimulus into a corresponding electrical signal to achieve
the sensing function. Among the reported various sensors, ca-
pacitive sensors relying on electrical double layers (EDLs) have
shown higher sensitivity, faster response time, and simpler de-
vice structure. In this research, ion-gel fibrous membranes are
prepared by electrospinning technology, based on which both the
iontronic capacitive sensors and triboelectric sensors are demon-
strated. Wherein, the iontronic capacitive sensor has high sensi-
tivity and stability, and the utilized ion-gel fibrousmembrane can
significantly improve the disadvantages of conventional capaci-
tive materials (e.g., rigidity and brittleness) with the advantages
of facile preparation and simple structure. Ionic liquid (IL) is an
ionic compound consisting of anions and cations,[37–41 ] which
has the feature of tunability and is one of the commonly used ma-
terials in the field of energy storage, electronic sensory devices,
and energy harvesting. Previous studies have shown that ion-gel
fibrous membranes prepared by doping ionic liquids into ma-
trix polymers not only have excellent mechanical properties but
also have high electrical conductivity. The ion gel with high ionic
conductivity can be formed by simply dissolving poly(vinylidene
fluoride-co-hexafluoropropylene) (P(VDF-HFP)) into ionic liquid
without any chemical crosslinkers, which is important for devices
such as flexible electronic devices and batteries.[42–44 ] Besides,
Adv. Funct. Mater. 2023,33, 2303723 © 2023 Wiley-VCH GmbH
2303723 (1 of 10)
