posted on 2021-09-29, 19:16authored byWen Wang, Shuang Wang, Chenxue Xiang, Shuying Liu, Mufang Li, Dong Wang
The rapid development of intelligent
technology and industry has
induced higher requirements for multifunctional materials, especially
intelligent materials with stimulus-responsive self-actuation behavior.
In this study, a Cu@PVA-co-PE/GO composite actuation film, with an
asymmetric sandwich structure, was prepared by attaching graphene
oxide (GO) to the surface of a polyvinyl alcohol ethylene copolymer
(PVA-co-PE) nanofiber composite film containing copper nanoparticles
(Cu) through layer-on-layer adsorption. This unique structural design
endowed the composite film with not only excellent structural stability
but also different bending directions (in response to moisture and
infrared light). The actuation performance shows that when the adsorption
time was 4 h, the maximum bending angle of the Cu@PVA-co-PE/GO composite
film was up to 90° within 5.99 s. Furthermore, the actuation
behavior was stable after 100 cycles of reversible moisture stimulation.
Additionally, the maximum actuation strain of the composite film was
up to 1.35 MPa during the illumination time of 6.8 s and maintained
an excellent stability for 400 s under continuous infrared stimulation
of 0.53 W/cm2. The rapid and sensitive stimulus response
of the Cu@PVA-co-PE/GO composite film exhibited self-actuation behavior
under the remote control of moisture and infrared light. This, in
turn, suggests prospects for wide applications in emerging technologies,
such as intelligent switches, artificial muscles, intelligent medical
treatment, and flexible robots.