Wei Wang

• PhD
• Professor at Harbin Institute of Technology (Shenzhen)

We synthesize snowman-shaped microrotors that are composed of TiO2 and SiO2 particles fused together and half-coated with Au. The microrotors rotate in the presence of fuel and UV light. The rotation speed can be readily modulated by the fuel concentration and light intensity. Such a microrotor serves as a mechanical micropump that hydrodynamically...

Large‐scale synthesis of micromotors powered by visible light and pure water is challenging, yet crucial for practical applications. Herein, a new method for large‐scale synthesis of uniform Janus ZnO micromotors is reported, by partially encapsulating a ZnO microsphere within a polysiloxane microsphere. The resulting micromotors autonomously move...

The ability to learn new functionalities on-the-fly is highly desired for micromotors operating in a changing environment. Here, we demonstrate how non-oscillatory micromotors transform into spontaneous oscillators, superficially resembling students...

Spatiotemporal coordination of a nanorobot ensemble is critical for their operation in complex environments, such as tissue removal or drug delivery. Current strategies of achieving this task, however, relies heavily on sophisticated, external manipulation. We here present an alternative, biomimetic strategy by which oscillating Ag Janus micromotor...

Synthetic active colloids that harvest energy stored in the environment and swim autonomously are a popular model system for active matter. This emerging field of research sits at the intersection of materials chemistry, soft matter physics, and engineering, and thus cross-talk among researchers from different backgrounds becomes critical yet diffi...

The design of powerful, more biocompatible microrobots calls for faster catalytic reactions. Here we demonstrate a two-fold increase in the speed of photocatalytic TiO2-metal Janus micromotors via a Au/Ag bi-layered coating. Electrochemical measurements show that such a bimetallic coating is a better photocatalyst than either metal alone. Similarly...

Photochemically powered micromotors are prototype microrobots, and spatio-temporal control is pivotal for a wide range of potential applications. Although their spatial navigation has been extensively studied, temporal control of photoactive micromotors remain much less explored. Using Ag-based oscillating micromotors as a model system, a strategy...

Precise control of the motion of micromachines is the key to achieving their functions for practical applications. The main challenge is that a given micromachine can typically exhibit only one motion mode, i.e. translation or rotation, while multiple modes of motion resulting from a simple actuation is still rare. Here we designed and synthesized...

The ability to precisely maneuver micro/nano objects in fluids in a contactless, biocompatible manner can enable innovative technologies and may have far-reaching impact in fields such as biology, chemical engineering, and nanotechnology. Here, we report a design for acoustically powered bubble-based microswimmers that are capable of autonomous mot...

There is mounting interest in synthetic microswimmers (“micromotors”) as microrobots as well as a model system for the study of active matters, and spatial navigation is critical for their success. Current navigational technologies mostly rely on magnetic steering or guiding with physical boundaries, yet limitations with these strategies are plenty...

The research progress in colloidal motors, synthetic colloids that convert environmental energy and swim in water, has attracted much attention in recent years. Yet, its rapid development and interdisciplinary nature has created a hurdle for beginners, especially students and postdocs. In light of this challenge, this tutorial review gives a bird's...

In article number 1807727, Xing Ma and co‐workers present an enzymatic micromotor functionalized with magnetic nanoparticles and photosensitizers, which can be actively propelled via a biocatalytic reaction and serve as a mobile photosensitizer platform for highly efficient photodynamic therapy (PDT). This platform can overcome the long‐standing bo...

Spontaneous periodicity is widely found in many biological and synthetic systems, and designing colloidal motors that mimic this feature may not only facilitate our understanding of how complexity emerges, but also enables applications that benefit from a time-varying activity. However, there is so far no report on a colloidal motor system that sho...

In many natural and artificial devices diffusive transport takes place in confined geometries with corrugated boundaries. Such boundaries cause both entropic and hydrodynamic effects, which have been studied only for the case of spherical particles. Here we experimentally investigate the diffusion of particles of elongated shape confined in a corru...

In many natural and artificial devices diffusive transport takes place in confined geometries with corrugated boundaries. Such boundaries cause both entropic and hydrodynamic effects, which have been studied only for the case of spherical particles. Here we experimentally investigate diffusion of particles of elongated shape confined into a corruga...

One of the recent frontiers of nanotechnology research involves machines that operate at nano- and microscales, also known as nano/micromotors. Their potential applications in biomedicine, environmental sciences and engineering, military and defense industries, self-assembly and many other areas have fueled an intense interest in this topic over th...

Precise manipulation of microparticles in microchannels is a primary technique for numerous lab-on-a-chip bioengineering research and applications, as it determines the chip's functions and analytical results. Acoustic manipulation, using the acoustic radiation force, is a compact, versatile and contactless manipulation technique, which can be easi...

We report a near‐infrared (NIR) light‐powered Janus mesoporous silica nanomotor (JMSNM) with macrophage cell membrane (MPCM) cloaking that can actively seek cancer cells and thermomechanically percolate cell membrane. Upon exposure to NIR light, a heat gradient across the Janus boundary of the JMSNMs is generated by the photothermal effect of the A...

Engines and motors are everywhere in the modern world, but it is a challenge to make them work if they are very small. On the micron length scale, inertial forces are weak and conventional motor designs involving, e.g., pistons, jets, or flywheels cease to function. Biological motors work by a different principle, using catalysis to convert chemica...

In article number 1706066, Guangyu Zhang, Longqiu Li, Wei Wang, and co‐workers report a magnetic surface walker that is precisely manipulated via an oscillating magnetic field. Magnetically coated Janus microspheres align and bind into dimers and leap into directional motion by alternating their two spheres back and forth in an asymmetric fashion d...

We investigate the dynamics of structured photoactive microswimmers and show that morphology sensitively determines swimming behavior. Particular to this study, a major portion of the light-activated particles’ underlying structure is built from a photocatalytic material, made possible by dynamic physical vapor deposition (DPVD). We find swimmers o...

Micromotors are an emerging class of micromachines that could find potential applications in biomedicine, environmental remediation and microscale self-assembly. Understanding their propulsion mechanisms holds the key to their future development. This is especially true for a popular category of micromotors that are driven by asymmetric surface pho...

Synthetic microswimmers, or micromotors, are finding potential uses in a wide range of applications, most of which involve boundaries. However, subtle yet important effects beyond physical confinement on the motor dynamics remain less understood. In this letter, glass substrates were functionalized with positively and negatively charged polyelectro...

Micromotors powered by megahertz ultrasound, first reported about 5 years ago, have lately been considered a promising platform for a wide range of microscale applications, yet we are only at the early stage of understanding their operating mechanisms. Through carefully designed experiments, and by comparing the results to acoustic theories, we pre...

We report the synthesis and properties of rod-shaped gold/iron oxide nanomotors that are powered by visible light in dilute hydrogen peroxide solutions. Electrochemical measurements confirmed that the light-driven nanomotors operate by a self-electrophoretic mechanism, modulated by the photovoltage and the photoconductivity of gold/iron oxide. Due...

Surface-swimming nano- and micromotors hold significant potential for on-chip mixing, flow generation, sample manipulation, and microrobotics. Here we describe rotating microrods magnetized nearly orthogonally to their long axes. When actuated near a solid surface, these microrods demonstrate precessing motion, with rods describing a double cone si...

In recent years, there is mounting interesting in the study of active matters that self-propel by consuming energy and therefore lie beyond thermal equilibrium. Examples include fish schools, bird flocks, bacteria colonies, and tissues made of live cells, to name a few. Mobility of the individual components of these groups, coupled with communicati...

Correction for 'Visible-light controlled catalytic Cu2O-Au micromotors' by Dekai Zhou, et al., Nanoscale, 2017, DOI: 10.1039/c6nr08088j.

Visible light driven Cu2O-Au micromotors exhibit rapid on/off switching and speed control. Electrochemical measurements confirm that the light-induced movement of the Cu2O-Au micromotors involves a self-electrophoresis mechanism modulated by the photoconductivity of Cu2O. This study extends the utilization of the electromagnetic spectrum for micro/...

There is mounting interest in designing magnetically steerable nano- and micromotors for next generation medical nanorobotics, which requires biocompatibility for each individual component. Although various magnetic materials (e.g., Ni, Co, and Fe3O4) have been incorporated into micromotors, their acid resistance remains largely unexplored. In this...

Synthetic microswimmers are envisioned to be useful in numerous applications, many of which occur in tightly confined spaces. It is therefore important to understand how confinement influences swimmer dynamics. Here we study the motility of bimetallic microswimmers in linear and curved channels. Our experiments show swimmer velocities increase, up...

We report the partial core-shell nanowire motors. These nanowires are fabricated using our previously developed electrodeposition-based technique, and their catalytic locomotion in the presence of H2O2 is investigated. Unlike conventional bimetallic nanowires that are self-electroosmotically propelled, our Au/Ru core-shell nanowires show both a not...

Bimetallic nanorods are propelled without chemical fuels in MHz acoustic fields, and exhibit similar behaviors to single-metal rods, including autonomous axial propulsion and organization into spinning chains. Shape asymmetry determines the direction of axial movement of bimetallic rods when there is a small difference in density between the two me...

Lab-on-a-chip devices have over the recent years attracted a significant amount of attention both in the academic circle and industry, due to their promise to deliver versatile functionalities with high throughput and low sample amount. Typically mechanical or electrokinetic micropumps are used in the majority of lab-on-a-chip devices that require...

Trisegmented Au-Ru-Au and Ru-Au-Ru nanorods catalyze the decomposition of hydrogen peroxide, pumping fluid along their axis as “pullers” and “pushers” respectively. Local flows generated by catalytic pumping influence the pairwise and higher aggregation of these particles. In particular, pullers avoid side-by-side contact and aggregate primarily th...

Synthetic nano- and microscale machines move autonomously in solution or drive fluid flows by converting sources of energy into mechanical work. Their sizes are comparable to analytes (sub-nano- to microscale), and they respond to signals from each other and their surroundings, leading to emergent collective behavior. These machines can potentially...

The assembly of complex structures from simpler, individual units is a hallmark of biology. Examples include the pairing of DNA strands, the assembly of protein chains into quaternary structures, the formation of tissues and organs from cells, and the self-organization of bacterial colonies, flocks of birds, and human beings in cities. While the in...

Highly oriented, crystalline anatase TiO2 nanorod films with a [001] preferred growth direction were grown on transparent conducting substrates and characterized as photoanodes for water photoelectrolysis. The nanorods were grown by a simple hydrothermal reaction in a mixture of hydrochloric and sulfuric acids at 180 ° for 4 h. The phase and morpho...

Synthetic microswimmers are a class of artificial nano- or microscale particle capable of converting external energy into motion. They are similar to natural microswimmers such as bacteria in behavior and are, therefore, of great interest to the study of active matter. Additionally, microswimmers show promise in applications ranging from bioanalyti...

Bimetallic gold-ruthenium microrods are propelled in opposite directions in water by ultrasound and by catalytic decomposition of hydrogen peroxide. This property was used to effect reversible swarming, to stall and reverse autonomous axial propulsion, and to study the chemically powered movement of acoustically levitated microrods.

We measure the microvortical flows around gold nanorods propelled by ultrasound in water using polystyrene nanoparticles as optical tracers. We infer the rotational frequencies of such nanomotors assuming a hydrodynamic model of this interaction. In this way, we find that nanomotors rotate around their longitudinal axes at frequencies of up to ≈ 2....

The ultrasonic propulsion of rod-shaped nanomotors inside living HeLa cells is demonstrated. These nanomotors (gold rods about 300 nm in diameter and about 3 μm long) attach strongly to the external surface of the cells, and are readily internalized by incubation with the cells for periods longer than 24 h. Once inside the cells, the nanorod motors...

The recent discovery of fuel-free propulsion of nanomotors using acoustic energy has provided a new avenue for using nanomotors in biocompatible media. Crucial to the application of nanomotors in biosensing and biomedical applications is the ability to remotely control and steer them toward targets of interest, such as specific cells and tissues. W...

Significance Microscale catalyst particles suspended in fluids can convert the energy of chemical reactions that occur on their surfaces to movement. Collections of particles undergoing powered motion exhibit behavior that mimics living microparticles such as bacteria: swarming, predator–prey interactions, and chemotaxis. These behaviors originate...

We analyze the power conversion efficiency of different classes of autonomous nano- and micromotors. For bimetallic catalytic motors that operate by a self-electrophoretic mechanism, there are four stages of energy loss, and together they result in a power conversion efficiency on the order of 10^-9. The results of finite element modeling agree wel...

Patterning of nanowires in a controllable, tunable manner is important for the fabrication of functional nanodevices. Here we present a simple approach for tunable nanowire patterning using standing surface acoustic waves (SSAW). This technique allows for the construction of large-scale nanowire arrays with well-controlled patterning geometry and s...

The acoustic radiation force concentrates particulate materials at the nodes or antinodes of an ultrasonic standing wave (USW), in function of different physicochemical parameters: size, shape, density or elastic properties. Thus, frequencies from 0.5 to 10 MHz are adapted for manipulating micron-sized particles, cells, bacteria, vesicles, drops, b...

Autonomously moving micro-objects, or micromotors, have attracted the attention of the scientific community over the past decade, but the incompatibility of phoretic motors with solutions of high ionic strength and the use of toxic fuels have limited their applications in biologically relevant media. In this letter we demonstrate that ultrasonic st...

CuInSe(2) nanowire arrays were fabricated by electrodeposition from aqueous solutions of copper sulfate, indium sulfate, selenium dioxide, and citric acid, using anodic alumina membranes as templates. X-ray diffraction patterns showed that the wires were single phase (chalcopyrite structure) but polycrystalline, and a band gap of ∼1 eV was obtained...