Extremely Stretchable and Tough Piezoelectric Gels for Artificial Electronic Skin
writer：Qingqing Li, Lianmin Chen, Mingyu Guo,* and Zhijun Hu*
keywords：artificial electronic skin, gel, piezoelectric, polymer, stretchable
source：期刊
specific source：Adv. Mater. Technol. 2021, 2101371
Issue time：2021年
Piezoelectric sensors and energy harvesters have received considerable
interest due to their self-powered capability and potential applications in
various electronic devices. However, it is still a challenge to fabricate stretchable
piezoelectric devices because piezoelectrics mainly consists of stiff
crystalline structures. Here, extremely stretchable and tough piezoelectric
gels are reported, which are prepared simply by swelling poly(ethylene glycol)
(PEG)-based poly(urethane-urea) (PUU) gels with aqueous solution of molecular
ferroelectrics. The hydrogen interactions between the PEG segments
in the gels and the molecular ferroelectrics (dabcoHReO4, DH) enable well
dispersion and crystallization of DH in the PEG segments. The resulted PUU/
DH composite piezoelectric gels exhibit unique tensile mechanical properties,
including superior strain (>1000%), high breaking strength (>10 MPa),
modulus (>2 MPa), and toughness (>57 MJ cm?3). The extremely stretchable
and tough piezoelectric gels show excellent piezoelectric properties (d33 ≈
62 pC N?1 for films with a 10 wt% of DH and light transparency (>90%), and
can quantitatively detect different mechanical deformations. Additionally,
the energy generators can harvest mechanical energy with a power density
of 1.7 μW cm?2. This work is expected to motivate new design principles for
fabricating piezoelectric materials with excellent mechanical and piezoelectric
properties for various applications.