Biomimetic remote handling and sensing devices of multiwalled carbon nanotubes and vanadium pentoxide

Abstract

Systems capable of managing toxic, reactive and explosive substances through remote handles like light and electricity have enormous technological significance. Here, we report the development of bilayer actuators of multiwalled carbon nanotubes (CNT)/oxidized multiwalled carbon nanotubes (o-CNT) and exfoliated two-dimensional (2D) flakes of vanadium pentoxide (VO) that can precisely handle reactive substances. The unequal photothermal activity of the carbon nanotubes-reconstructed VO were exploited to fabricate the bilayer membranes (CNT-VO) displaying light-controlled shape morphing characteristics (bending speed up to 45° s−1 with light intensity 15 k lux). Similarly, the unparalleled Joule heating effect of o-CNT and VO membranes (o-CNT-VO) was exploited to create electrical voltage-driven actuation (bending speed up to 64.5 °s−1 with an applied voltage of 12 V) of the bilayer membrane. While the light-responsive behaviour of the CNT-VO bilayer membrane was exploited to pick up and drop off reactive chemicals like potassium permanganate (KMnO4), and sodium (Na) metal (up to ten times its body weight), the voltage responsiveness and rose petal effect of o-CNT-VO were used for transporting microdroplets (25 µL) of toxic chemicals like sulfuric acid (H2SO4) and sodium hydroxide (NaOH). Similar to fingers the CNT-VO-based actuators sense the nature of the objects/materials it is picking-up or dropping-off . Owing to the inherent robustness of components, the shape-morphing characteristics of CNT-VO strips survived dipping into acidic, basic and organic liquids.