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Creators/Authors contains: "Guo, Jianhe"

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  1. null (Ed.)
  2. Abstract

    2D transition‐metal‐dichalcogenide materials, such as molybdenum disulfide (MoS2) have received immense interest owing to their remarkable structure‐endowed electronic, catalytic, and mechanical properties for applications in optoelectronics, energy storage, and wearable devices. However, 2D materials have been rarely explored in the field of micro/nanomachines, motors, and robots. Here, MoS2 with anatase TiO2 is successfully integrated into an original one‐side‐open hollow micromachine, which demonstrates increased light absorption of TiO2‐based micromachines to the visible region and the first observed motion acceleration in response to ionic media. Both experimentation and theoretical analysis suggest the unique type‐II bandgap alignment of MoS2/TiO2 heterojunction that accounts for the observed unique locomotion owing to a competing propulsion mechanism. Furthermore, by leveraging the chemical properties of MoS2/TiO2, the micromachines achieve sunlight‐powered water disinfection with 99.999% Escherichia coli lysed in an hour. This research suggests abundant opportunities offered by 2D materials in the creation of a new class of micro/nanomachines and robots.

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  3. Abstract

    Constructing colloidal particles into functional nanostructures, materials, and devices is a promising yet challenging direction. Many optical techniques have been developed to trap, manipulate, assemble, and print colloidal particles from aqueous solutions into desired configurations on solid substrates. However, these techniques operated in liquid environments generally suffer from pattern collapses, Brownian motion, and challenges that come with reconfigurable assembly. Here, we develop an all-optical technique, termed optothermally-gated photon nudging (OPN), for the versatile manipulation and dynamic patterning of a variety of colloidal particles on a solid substrate at nanoscale accuracy. OPN takes advantage of a thin surfactant layer to optothermally modulate the particle-substrate interaction, which enables the manipulation of colloidal particles on solid substrates with optical scattering force. Along with in situ optical spectroscopy, our non-invasive and contactless nanomanipulation technique will find various applications in nanofabrication, nanophotonics, nanoelectronics, and colloidal sciences.

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  5. Abstract

    To release biosubstances, including drug molecules, DNAs, and proteins, at prescribed cellular and tissue locations with controllable rates is the Holy Grail of drug delivery that could enable an array of unprecedentedin vitroandin vivoapplications. Extensive research efforts have been focused on exploring innovative mechanisms and approaches for controlling biochemical release with prescribed dose, timing, and dynamics. Particularly, the utilization of electric fields to stimulate the release of biomolecules from synthesized micro/nanostructures has received considerable interest. In this review, we focus on the recent progresses in controlling the release of biomolecules with electric fields by a variety of mechanisms, including electrochemical desorption and actuation, electrically triggered erosion, and electrically driven nanopumps and mechanical motions. The research on external electric stimuli trigged biorelease has progressed rapidly and could make remarkable impact in single‐cell biology, cell‐cell communication, and drug discovery.

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  6. Abstract

    Recent progress in artificial nanomachines offers promising solutions to grand challenges in biochemical delivery and diagnostics. In this work, advances of micro/nanomachines made of synthesized micro/nanostructures for applications in delivery and detection of biomolecules are reviewed, along with a discussion of pros and cons of each type of machine. The review of micro/nanomachines is categorized according to their working mechanisms, including motion actuation realized by magnetic, electric, and acoustic fields and chemical reactions. The developments of micro/nanomachines are discussed in depth in the fabrication, propulsion, and motion control, loading and releasing of micro/nanosubstances, and biochemical sensing. The rapid development of man‐made miniaturized machines paves the road toward future intelligent nanorobots and nanofactories that can revolutionize society.

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