LANGMUIR
·
2021
·
IF 3.882
Yunyu Sun,Jiwei Jiang,Guangju Zhang,Ningning Yuan,Hui Zhang,Bo Song,Bin Dong
Light-driven micromotor has become one of the research focuses in the past decade, and its motion behavior is usually controlled by light intensity, polarization, and light wavelength. Herein, the light incident angle is utilized to control the motion behavior of silica/Au/pentacene (SiO2/Au/PEN) spherical Janus micromotor. Under tilted irradiation, a single micromotor shows positive phototactic moving behavior without the addition of external chemical fuels, which relies on the photocatalytic reactions and the self-electrophoresis mechanism. Interestingly, when the incident light is tuned to the vertical angle, the SiO2/Au/PEN micromotor stops moving. Similarly, a number of SiO2/Au/PEN micromotors exhibit the same “on–off” motion change, which is dependent on the light incident angle. More interestingly, the “on–off” motion of the SiO2/Au/PEN microparticles under vertical light irradiation results in the formation of the agglomeration with position and size precisely controlled by light. In addition, the resulting aggregation exhibits light-controlled dynamic migration behavior. The incident angle control thus opens up new opportunities for the motion control of the micromotors for diverse applications.
研究领域:
材料科学
·
纳米技术
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Soft Matter
·
2025
·
IF 2.8
Jiayu Liu,Yankai Xu,Zihan Qiao,Shanshan Li,Xing Ma,Ting Kuang,H. P. Zhang,Wei Wang
Active colloids powered by self-generated gradients are influenced by nearby solid boundaries, leading to their reorientation. In this study, the tilt angles (the angle between where an active colloid moves and where it faces) were measured to be 13.3° and −33.9° for 5 μm polystyrene microspheres half coated with 10 nm Pt caps moving in 5% H2O2 along the bottom and top glass wall, respectively, indicating that the colloids moved with their PS (forward) caps tilted slightly toward the wall. The speeds and tilt angles of Pt Janus colloids increased consistently with increasing H2O2 concentration (0.5 to 10 v/v%) and Pt cap thickness (5 to 50 nm). We propose that the tilt results from a balance between gravitational torque (caused by the Pt cap's weight) and chemical activity-induced torque (from self-generated chemical gradients), qualitatively supported by finite element simulations based on self-electrophoresis. Our findings are useful for understanding how chemically active colloids move in, and interact with, their environment.
研究领域:
胶体科学
·
物理化学
·
界面现象研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Applied Materials Today
·
2021
·
IF 10.041
Rencheng Zhuang,Dekai Zhou,Xiaocong Chang,Yi Mo,Guangyu Zhang,Longqiu Li
Design and synthesis of electric-driven micro/nanomotors (EDMNMs) have attracted tremendous attention because of their unique advantages, such as non-necessity of fuel, high mobility, and flexible controllability. However, existing EDMNMs are mostly Janus structures based on two hemispheres made from heterogeneous materials . Here, we propose a new type of defective electric-driven micro/nanomotor with an asymmetric shape. It is found, for the first time, that the defective golden micro/nanomotors (DGMs) can generate a locally asymmetric field gradient through the topological defect, and can achieve controllable self-dielectrophoresis (sDEP) and induced-charge electrophoresis (ICEP) motion behaviors in different frequency ranges. In particular, the DGMs can achieve three-dimensional helical motion behavior through designing their defective structure. Furthermore, we demonstrate that the DGMs can attract or repel cargos under different electric frequencies. These new DGMs and their attractive performance pave the way for fabricating highly controllable EDMNMs via structural design and can be widely applied in biomedicine, micro/nanosensors, and micro/nanomechanical systems.
研究领域:
材料科学
·
生物医学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Huaide Jiang,Xiaoli He,Yanmei Ma,Bi Fu,Xingui Xu,Balachandran Subramanian,Chengzhi Hu
Directional motion in response to specific signals is critically important for micro/nanomotors in precise cargo transport, obstacle avoidance, collective control, and complex maneuvers. In this work, a kind of isotropic light-driven micromotor that is made of hedgehog-shaped TiO2 and functional multiwall carbon nanotubes (Hs-TiO2@FCNTs) has been developed. The FCNTs are closely entangled with Hs-TiO2 and form a close-knit matrix on the surface of Hs-TiO2, which facilitates the transfer of electrons from Hs-TiO2 to FCNTs. Due to the high redox potential of Hs-TiO2, excellent electron–hole separation efficiency by the addition of FCNTs, and isotropic morphology of the micromotor, these Hs-TiO2@FCNT micromotors show phototactic and fuel-free propulsion under unidirectional irradiation of UV light. It is the first time to demonstrate isotropic micromotors that are propelled by self-electrophoresis. The isotropy of Hs-TiO2@FCNT micromotors makes them immune to the rotational Brownian diffusion and local flows, exhibiting superior directionality. The motion direction of our micromotors can be precisely tuned by light and a velocity of 8.9 μm/s is achieved under 160 mW/cm2 UV light illumination. Photodegradation of methylene blue and active transportation of polystyrene beads are demonstrated for a proof-of-concept application of our micromotors. The isotropic design of the Hs-TiO2@FCNT micromotors with enhanced photocatalytic properties unfolds a new paradigm for addressing the limitations of directionality control and chemical fuels in the current asymmetric light-driven micromotors.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
Nanoscale
·
2015
·Vol. 8
·期 9
·4976-4983
·
IF 7.394
Fangzhi Mou,Lei Kong,Chuanrui Chen,Zhihong Chen,Leilei Xu,Jianguo Guan
In this work, water-fuelled TiO2/Pt Janus submicromotors with light-controlled motions have been developed by utilizing the asymmetrical photocatalytic water redox reaction over TiO2/Pt Janus submicrospheres under UV irradiation. The motion state, speed, aggregation and separation behaviors of the TiO2/Pt Janus submicromotor can be reversibly, wirelessly and remotely controlled at will by regulating the “on/off” switch, intensity and pulsed/continuous irradiation mode of UV light. The motion of the water-fuelled TiO2/Pt Janus submicromotor is governed by light-induced self-electrophoresis under the local electrical field generated by the asymmetrical water oxidation and reduction reactions on its surface. The TiO2/Pt Janus submicromotors can interact with each other through the light-switchable electrostatic forces, and hence continuous and pulsed UV irradiation can make the TiO2/Pt Janus submicromotors aggregate and separate at will, respectively. Because of the enhanced mass exchange between the environment and active submicromotors, the separated TiO2/Pt Janus submicromotors powered by the pulsed UV irradiation show a much higher activity for the photocatalytic degradation of the organic dye than the aggregated TiO2/Pt submicromotors. The water-fuelled TiO2/Pt Janus submicromotors developed here have some outstanding advantages as “swimming” photocatalysts for organic pollutant remediation in the macro or microenvironment (microchannels and microwells in microchips) because of their small size, long-term stability, wirelessly controllable motion behaviors and long life span.
研究领域:
纳米技术
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）