Light-controlled two-dimensional TiO₂ plate micromotors

Abstract

In this work, UV light-controlled two-dimensional (2D) TiO 2 plate micromotors are demonstrated for the first time. The 2D TiO 2 micromotors are produced by the well-known anodic oxidation method in combination with a cracking and separation process. When the motor is placed in H 2 O 2 aqueous solution under UV irradiation, oxygen bubbles are generated in the holes of the TiO 2 membrane. The 2D micromotor thus moves upon O 2 bubbles under its own weight. In contrast to bubble-propelled micromotors, which require an addition of surfactants to chemical fuels, the 2D micromotor is capable of moving in aqueous H 2 O 2 solution without surfactants. Moreover, speed of the 2D TiO 2 micromotor can be controlled by the intensity of the UV light. Such surfactant-free micromotors and their facile fabrication hold considerable promise for diverse practical applications in the biomedical and energy fields, for example, and in new materials. Fig. 1 (a) SEM image of the sample. (b) EDX spectrum and XRD pattern (inset) of the as-prepared sample.

Titania-Based Micro/Nanomotors: Design Principles, Biomimetic Collective Behavior, and Applications

“…Successive bubble ejection from one opening of the tubular TiO 2 micromotors result in sequential recoil forces leading to propulsion (Figure 2A). Similarly, lightdriven TiO 2 nanotube arrays and TiO 2 plates have also been reported [20,21]. However, Chen and colleagues were the first to show phototaxis of isotropic micromotors based on asymmetric light irradiation (Figure 2B) [8].…”

Visible-Light-Driven Asymmetric TiO2-Based Photocatalytic Micromotor Hybridized with a Conjugated Polyelectrolyte and Glucose Oxidase

“…The surfactant could reduce the surface tension of the micromotor, leading to a higher particle speed. 36,37 However, use of more than 7 wt % retarded the displacement of JWSP@TMPN@JGO x presumably because of the changes in the viscosity of the solution. 38 Such motion trajectories and speeds of JWSP@TMPN@ JGO x were evaluated quantitatively with and without visible light irradiation (Figure 11).…”

“…The displacement of JWSP@TMPN@JGO x increased as the surfactant concentration increased from 0 to 7 wt %. The surfactant could reduce the surface tension of the micromotor, leading to a higher particle speed. , However, use of more than 7 wt % retarded the displacement of JWSP@TMPN@JGO x presumably because of the changes in the viscosity of the solution …”

Enzyme‐Photocatalyst Tandem Microrobot Powered by Urea for Escherichia coli Biofilm Eradication

“…Previous studies have demonstrated that TiO 2 -based nanotube bundles stand as a versatile, smart, and biocompatible platform for tissue engineering, drug delivery, and biosensing. [20] Although there are a few works on microrobots based on TiO 2 nanotube bundles, [27,28] these require UV photoactivation, a high concentration of H 2 O 2 (10% wt. ), and/or surfactants.…”