Light-driven synthetic micro-/nanomotors have attracted considerable attention in recent years due to their unique performances and potential applications. We herein demonstrate the dye-enhanced self-electrophoretic p...Light-driven synthetic micro-/nanomotors have attracted considerable attention in recent years due to their unique performances and potential applications. We herein demonstrate the dye-enhanced self-electrophoretic propulsion of light-driven Ti O_2–Au Janus micromotors in aqueous dye solutions. Compared to the velocities of these micromotors in pure water, 1.7, 1.5, and 1.4 times accelerated motions were observed for them in aqueous solutions of methyl blue(10-5g L^(-1)), cresol red(10^(-4)g L^(-1)),and methyl orange(10^(-4)g L^(-1)), respectively. We determined that the micromotor speed changes depending on thetype of dyes, due to variations in their photodegradation rates. In addition, following the deposition of a paramagnetic Ni layer between the Au and Ti O_2 layers, the micromotor can be precisely navigated under an external magnetic field. Such magnetic micromotors not only facilitate the recycling of micromotors, but also allow reusability in the context of dye detection and degradation.In general, such photocatalytic micro-/nanomotors provide considerable potential for the rapid detection and ‘‘on-thefly'' degradation of dye pollutants in aqueous environments.展开更多
The advancement in the micro-/nanofabrication techniques has greatly facilitated the development of micromotors.A variety of micromotors have been invented with powerful functions,which have attracted a broad range of...The advancement in the micro-/nanofabrication techniques has greatly facilitated the development of micromotors.A variety of micromotors have been invented with powerful functions,which have attracted a broad range of interests from chemistry, physics,mechanics,biology and medicine.In this paper,we reviewed recent progress in micromotors and highlighted representative works.The mechanisms of micromotors by internal and external energy sources were described.We described general fabrication strategies of the popular micromotors (wire,tubular,helical and Janus)including bottom-up and top-down approaches.In the application section,we primarily focused on the biological applications,such as biological cargo delivery, biosensing and surgery.At last,we discussed the current challenges and provided future prospects.展开更多
Considerable efforts have been devoted to treating gastric ulcers.Attempts in this field tend to develop drug delivery systems with prolonged gastric retention time.Herein,we develop novel Chinese herb pollen-derived ...Considerable efforts have been devoted to treating gastric ulcers.Attempts in this field tend to develop drug delivery systems with prolonged gastric retention time.Herein,we develop novel Chinese herb pollen-derived micromotors as active oral drug delivery system for treating gastric ulcer.Such Chinese herb pollen-derived micromotors are simply produced by asymmetrically sputtering Mg layer onto one side of pollen grains.When exposed to gastric juice,the Mg layer can react with the hydrogen ions,resulting in intensive generation of hydrogen bubbles to propel the micromotors.Benefiting from the autonomous motion and unique spiny structure,our micromotors can move actively in the stomach and adhere to the surrounding tissues.Besides,their special architecture endows the micromotors with salient capacity of drug loading and releasing.Based on these features,we have demonstrated that our Chinese herb pollen-derived micromotors could effective deliver berberine hydrochloride and show desirable curative effect on the gastric ulcer model of mice.Therefore,these Chinese herb pollen-derived micromotors are anticipated to serve as promising oral drug delivery carriers for clinical applications.展开更多
Inspired by the ubiquitous helical structures in nature,research on artificial helices has attracted increasing attention.As a unique and complex three-dimensional(3D)geometry in the microscopic world,the micro-/nano ...Inspired by the ubiquitous helical structures in nature,research on artificial helices has attracted increasing attention.As a unique and complex three-dimensional(3D)geometry in the microscopic world,the micro-/nano helix has significant advantages in wide applications due to its distinctive properties at the micro-scale.Micro-/nanotechnology is advancing rapidly.The geometric complexity of helical structure poses technical challenges for the manufacturing at the micro-/nanoscale,requiring some emerging manufacturing techniques.In this review,we systematically classify and summarize existing manufacturing methods for micro/nano helical structures and their underlying mechanisms.Based on the unique physical properties of helical structures at the microscale,their latest applications are analyzed across different fields.Finally,we conclude the challenges and future research directions of micro-/nano helices in manufacturing methods and applications.展开更多
In this study, we report a spindle-like micromotor. This device, which is fabricated using a one-step electrospinning method, consists of biodegradable polycaprolactone and an anionic surfactant. Intriguingly, not onl...In this study, we report a spindle-like micromotor. This device, which is fabricated using a one-step electrospinning method, consists of biodegradable polycaprolactone and an anionic surfactant. Intriguingly, not only can the resulting micromotor move autonomously on the surface of water for a long period of time （-40 min） due to the Marangoni effect, but it also exhibits a pH sensing behavior due to variations in the surface tension caused by the release of surfactant under different pH conditions. More interestingly, we reveal that the motion-based pH sensing property is size-dependent, with smaller structures exhibiting a higher sensitivity. In addition, since polycaprolactone is a biode- gradable material, the micromotor described in this study can be easily degraded in solution. Hence, features such as one-step fabrication, motion readout, and biodegradability render this micromotor an attractive candidate for sensing algplications.展开更多
A new rod-shaped traveling wave ultrasonic micromotor is developed. In the micromotor, five pieces of piezoelectric ceramics clamped by two metal cylinders are used as its stator. The driving principle of the rodshape...A new rod-shaped traveling wave ultrasonic micromotor is developed. In the micromotor, five pieces of piezoelectric ceramics clamped by two metal cylinders are used as its stator. The driving principle of the rodshaped ultrasonic motor is simulated. The stator structure and the position to lay these piezoelectric ceramics are calculated to improve the electro mechanical conversion efficiency. A flexible rotor is designed to reduce the radial slip between the stator and the rotor, and to improve the motor efficiency. The prototype motor and its micror driver are tested. The motor is 9 mm in out-diameter, 15 mm in length and 3.2 g in weight. When the motor operates with the first bending frequency （72 kHz） of the stator, its maximal rotational speed and the torque reach 520 r/rain and 4.5 mN · m. Results show that the motor has good stability. The speed fluctuation is controlled within 3% by the frequency automatic tracking technique.展开更多
Micro/nanomotors present considerable potential in various fields,such as medical treatment,environmental remediation,and cell engineering.However,their restricted lifetime and issues in navigation control hinder thei...Micro/nanomotors present considerable potential in various fields,such as medical treatment,environmental remediation,and cell engineering.However,their restricted lifetime and issues in navigation control hinder their applications in cases requiring precise positioning without chemical fuels.Thus,we propose a tubular micromotor driven by external magnetic fields,enabling it to swim in water with accurate transport capabilities.The presented tubular micromotor incorporates a single-sided base,which increases the contact area to enable cargo delivery in liquid environments.The micromotor exhibits varied movement behaviors by applying different magnetic fields,and frequency modulation allows for control over movement velocity.Template-assisted electrochemical deposition is employed to achieve large-scale fabrication,which enables the construction of Ni–Au tubular micromotors with a single-sided base.In addition,the micromotor can trace a predefined path,which demonstrates its precise positioning ability.The cargo transport capability of the micromotor is further validated using polystyrene globules as cargo.This fuel-free tubular micromotor,which is driven by magnetic fields,provides a promising approach for precise cargo delivery.Its broad feasibility makes it suitable for various biomedical applications.展开更多
The modeling and evaluation of a prototype rotary micromotor where the annular rotor is supported electrostatically in five degrees of freedom is presented in order to study the behavior of this levitated micromotor a...The modeling and evaluation of a prototype rotary micromotor where the annular rotor is supported electrostatically in five degrees of freedom is presented in order to study the behavior of this levitated micromotor and further optimize the device geometry. The analytical torque model is obtained based on the principle of a planar variable-capacitance electrostatic motor while the viscous damping caused by air film between the stator and rotor is derived using laminar Couette flow model. Simulation results of the closed-loop drive motor, based on the developed dynamic model after eliminating mechanical friction torque via electrostatic suspension, are presented. The effects of the high-voltage drive, required for rotation of the rotor, on overload capacity and suspension stiffness of the electrostatic bearing system are also analytically evaluated in an effort to determine allowable drive voltage and attainable rotor speed in operation. The analytical results show that maximum speed of the micromotor is limited mainly by viscous drag torque and stiffness of the bearing system. Therefore, it is expected to operate the device in vacuum so as to increase the rotor speed significantly, especially for those electrostatically levitated micromotors to be used as an angular rate micro-gyroscope.展开更多
In this paper, we report fabrication of the bimetallic Janus microsphere, a magnesium microsphere with a silver surface coating, through thermal evaporation technique. Because of the Janus structure, this micromotor c...In this paper, we report fabrication of the bimetallic Janus microsphere, a magnesium microsphere with a silver surface coating, through thermal evaporation technique. Because of the Janus structure, this micromotor can be propelled in two different directions by the surface silver or magnesium ‘engine' and hydrogen peroxide or water fuel. In addition, due to the bactericidal property of silver, this autonomous micromotor is capable of killing bacteria in solution. As compared to the static one, the micromotor is able to kill the bacteria at a much faster rate(about nine times of that of the static one),demonstrating the superiority of the motion one. We thus believe that the micromotor shown in the current study is potentially attractive for the environmental hygiene applications.展开更多
Biocompatible designed micromotor has attracted more and more concerns in the field of biomedicine due to their self-propulsion and delivery abilities.Such micromotors,mostly consisting of alkali earth metals,hydrogel...Biocompatible designed micromotor has attracted more and more concerns in the field of biomedicine due to their self-propulsion and delivery abilities.Such micromotors,mostly consisting of alkali earth metals,hydrogels,or other motile biomaterials,can effectively transform chemical energy into mechanical or kinetic energy to achieve the expected delivery of cargos to the sites of action.Except for conveying power,the modifiable surface and inner cavity of micromotors guarantee that their potential as versatile delivery systems for therapeutic agents.Here,this review generalizes the propelling mechanisms,composites,and shapes of micromotors.Besides,the application of micromotor-derived composites for biomedicine delivery and other versatile purposes are also discussed.展开更多
Micromotors are widely used in cell operation,drug delivery and environmental decontamination due to their small size,low energy consumption and large propelling power.Compared to traditional Janus micromotor,the shel...Micromotors are widely used in cell operation,drug delivery and environmental decontamination due to their small size,low energy consumption and large propelling power.Compared to traditional Janus micromotor,the shell Janusmicromotor has better motion performance.However,the structural optimization of itsmotion performance is still unclear.The main factor restricting the motion performance of shell Janus micromotors is the drag forces.In the current work,theoretical analysis and numerical simulation were applied to analyze the drag forces of shell Janus micromotors.This study aims to design the optimum structure of shell Janus micromotors with minimum drag forces and obtain the magnitude of drag forces considering both the internal and external fluids of the shell Janus micromotors.Moreover,the influence of the motor geometry and Reynolds number on the drag coefficient was analyzed using numerical simulations.The results provide guidance for the optimum flow velocity,opening diameter and shell thickness to achieve minimum drag force.展开更多
A 1 mm diameter electromagnetic micromotor was developed as a crux component for MEMS application. The motor has a novel layer structure with a 1 mm diameter rotor in the middle of two stators with the same size. The ...A 1 mm diameter electromagnetic micromotor was developed as a crux component for MEMS application. The motor has a novel layer structure with a 1 mm diameter rotor in the middle of two stators with the same size. The stator uses multiple layers, slotless and concentrated planar winding. The rotor adopts multipolar permanent magnet with high performance. Ruby bearing is used to prolong operating lifetime of the micromotor. The stator winding, consisting of 6 layer coils, 42 turns, and 9 pairs, is fabricated with microprocessing techniques. The micromotor has long operation lifetime, its running speed is stable and controllable, and rotational direction can be easily reversed. Maximum achieved rotational speed of 18000 r/min with maximum output torque of 1.5 μ N·m has been obtained. This paper presented the key technology for developing this kind of micromotor including the design of structure, magnetic circuit, heat problem, friction improvement, microprocessing techniques, and so on.展开更多
A multi-try counter-meshing gears (CMG) discrimination device based on micro electromechani-cal system (MEMS) technology was designed for some specified information fields. The discrimination device consists of two gr...A multi-try counter-meshing gears (CMG) discrimination device based on micro electromechani-cal system (MEMS) technology was designed for some specified information fields. The discrimination device consists of two groups of metal CMG, two pawl/ratchet mechanisms, two driving micromotors and two re-setting micromotors, which make the CMG withdraw by raising the pawls. The energy-coupling element is a photoelectric sensor with a circular plate which is notched. Micromotor is fabricated using the ultraviolet LiGA (UV-LiGA) fabrication process and precision mechanical engineering. The discrimination device has the function which can automatically reset, with the correct resetting code, it can be tried another times.展开更多
This paper presents the formulation and practical implementation of positioning methodologies that compensate for the nonholonomic constraints of a mobile microrobot that is driven by two vibrating direct current(DC) ...This paper presents the formulation and practical implementation of positioning methodologies that compensate for the nonholonomic constraints of a mobile microrobot that is driven by two vibrating direct current(DC) micromotors. The open-loop and closed-loop approaches described here add the capability for net sidewise displacements of the microrobotic platform. A displacement is achieved by the execution of a number of repeating steps that depend on the desired displacement, the speed of the micromotors, and the elapsed time. Simulation and experimental results verified the performance of the proposed methodologies.展开更多
CONSPECTUS:The concept of micrometer-scale swimming robots,also known as microswimmers,navigating the human body to perform robotic tasks has captured the public imagination and inspired researchers through its numero...CONSPECTUS:The concept of micrometer-scale swimming robots,also known as microswimmers,navigating the human body to perform robotic tasks has captured the public imagination and inspired researchers through its numerous representations in popular media.This attention highlights the enormous interest in and potential of this technology for biomedical applications,such as cargo delivery,diagnostics,and minimally invasive surgery,as well as for applications in microfluidics and manufacturing.To achieve the collective behavior and control required for microswimmers to effectively perform such actions within complex,in vivo and microfluidic environments,they must meet a strict set of engineering criteria.These requirements include,but are not limited to,small size,structural monodispersity,flexibility,biocompatibility,and multifunctionality.Additionally,microswimmers must be able to adapt to delicate environments,such as human vasculature,while safely performing preprogrammed tasks in response to chemical and mechanical signals.Naturally information-bearing biopolymers,such as peptides,RNA,and DNA,can provide programmability,multifunctionality,and nanometer-scale precision for manufactured structures.In particular,DNA is a useful engineering material because of its predictable and well-characterized material properties,as well as its biocompatibility.Moreover,recent advances in DNA nanotechnology have enabled unprecedented abilities to engineer DNA nanostructures with tunable mechanics and responsiveness at nano-and micrometer scales.Incorporating DNA nanostructures as subcomponents in microswimmer systems can grant these structures enhanced deformability,reconfigurability,and responsiveness to biochemical signals while maintaining their biocompatibility,providing a versatile pathway for building programmable,multifunctional microand nanoscale machines with robotic capabilities.In this Account,we highlight our recent progress toward the experimental realization of responsive microswimmers made with compliant DNA components.We present a hybrid top-down,bottom-up fabrication method that combines templated assembly with structural DNA nanotechnology to address the manufacturing limitations of flexibly linked microswimmers.Using this method,we construct microswimmers with enhanced structural complexity and more controlled particle placement,spacing,and size,while maintaining the compliance of their DNA linkage.We also present a novel experimental platform that utilizes two-photon polymerization(TPP)to fabricate millimeter-scale swimmers(milliswimmers)with fully customizable shapes and integrated flexible linkers.This platform addresses limitations related to population-level heterogeneity in micrometer-scale systems,allowing us to isolate the effects of milliswimmer designs from variations in their physical dimensions.Using this platform,we interrogate established hydrodynamic models of microswimmer locomotion and explore how design and actuation parameters influence milliswimmer velocity.We next explore opportunities for enhancing microswimmer responsiveness,functionality,and physical intelligence through the inclusion of nucleic acid subcomponents.Finally,we highlight how our parallel research on xeno nucleic acids and interfacing DNA nanotechnology with living cells can enable the creation of fully organic,truly biocompatible microswimmers with enhanced functionality,improving the viability of microswimmers for applications in healthcare,manufacturing,and synthetic biology.展开更多
Traditional gyrocompasses,while capable of providing autonomous directional guidance and path correction,face limitations in widespread applications due to their large size,making them unsuitable for compact devices.M...Traditional gyrocompasses,while capable of providing autonomous directional guidance and path correction,face limitations in widespread applications due to their large size,making them unsuitable for compact devices.Microelectromechanical system(MEMS)gyrocompasses offer a promising alternative for miniaturization.However,current MEMS gyrocompasses require the integration of motor rotation modulation technology to achieve high-precision north-finding,whereas conventional motors in previous research introduce large volume and residual magnetism,thus undermining their size advantage.Here,we innovatively propose a miniature MEMS gyrocompass based on a MEMS traveling-wave micromotor,featuring the first integration of a chip-scale rotational actuator and combined with a precise multi-position braking control system,enabling high accuracy and fast north-finding.The proposed gyrocompass made significant advancements,reducing its size to 50×42.5×24.5 mm^(3)and achieving an azimuth accuracy of 0.199°within 2 min,which is half the volume of the smallest existing similar devices while offering twice the performance.These improvements indicate that the proposed gyrocompass is suitable for applications in indoor industrial robotics,autonomous driving,and other related fields requiring precise directional guidance.展开更多
The biointerface engineering of living cells by creating an abiotic shell has important implications for endowing cells with exogenous properties with improved cellular behavior,which then boosts the development of th...The biointerface engineering of living cells by creating an abiotic shell has important implications for endowing cells with exogenous properties with improved cellular behavior,which then boosts the development of the emerging field of living cell hybrid materials.Herein,we develop a way to perform active nanoencapsulation of single cell,which then endows the encapsulated cells with motion ability that they do not inherently possess.The emerging motion characteristics of the encapsulated cells could be self-regulated in terms of both the motion velocity and orbits by different proliferation modes.Accordingly,by taking advantage of the emergence of differentiated moving abilities,we achieve the self-sorting between mother cells and daughter cells in a proliferated Saccharomyces cerevisiae cell community.Therefore,it is anticipated that our highlighted study could not only serve as a new technique in the field of single-cell biology analysis and sorting such as in studying the aging process in Saccharomyces cerevisiae,but also open up opportunities to manipulate cell functionality by creating biohybrid materials to fill the gap between biological systems and engineering abiotic materials.展开更多
"Active" components can be introduced into a passive system to completely change its physical behavior from its typical behavior at thermodynamic equilibrium. To reveal the interaction mechanisms between ind..."Active" components can be introduced into a passive system to completely change its physical behavior from its typical behavior at thermodynamic equilibrium. To reveal the interaction mechanisms between individuals, researchers have designed unique self-propelled particles to mimic the collective behavior of biological systems. This review focuses on recent theoretical and experimental advances in the study of self-propelled particle systems and their individual and collective behaviors. The potential applications of active particles in chemical, biological and environmental sensing and single particle imaging are discussed.展开更多
Micro/nanorobots are promising for a wide range of biomedical applications(such as targeted tumor,thrombus,and infection therapies in hard-to-reach body sites)because of their tiny size and high maneuverability throug...Micro/nanorobots are promising for a wide range of biomedical applications(such as targeted tumor,thrombus,and infection therapies in hard-to-reach body sites)because of their tiny size and high maneuverability through the actuation of external fields(e.g.,magnetic field,light,ultrasound,electric field,and/or heat).However,fully synthetic micro/nanorobots as foreign objects are susceptible to phagocytosis and clearance by diverse phagocytes.To address this issue,researchers have attempted to develop various cytomembrane-camouflaged micro/nanorobots by two means:(1)direct coating of micro/nanorobots with cytomembranes derived from living cells and(2)the swallowing of micro/nanorobots by living immunocytes via phagocytosis.The camouflaging with cytomembranes or living immunocytes not only protects micro/nanorobots from phagocytosis,but also endows them with new characteristics or functionalities,such as prolonging propulsion in biofluids,targeting diseased areas,or neutralizing bacterial toxins.In this review,we comprehensively summarize the recent advances and developments of cytomembrane-camouflaged medical micro/nanorobots.We first discuss how cytomembrane coating nanotechnology has been employed to engineer synthetic nanomaterials,and then we review in detail how cytomembrane camouflage tactic can be exploited to functionalize micro/nanorobots.We aim to bridge the gap between cytomembrane-cloaked micro/nanorobots and nanomaterials and to provide design guidance for developing cytomembrane-camouflaged micro/nanorobots.展开更多
We report a fuel-free, near-infrared （NIR）-driven Janus microcapsule motor. The Janus microcapsule motors were fabricated by template-assisted polyelectrolyte layer-by-layer assembly, followed by spraying of a gold ...We report a fuel-free, near-infrared （NIR）-driven Janus microcapsule motor. The Janus microcapsule motors were fabricated by template-assisted polyelectrolyte layer-by-layer assembly, followed by spraying of a gold layer on one side. The NIR-powered Janus motors achieved high propulsion with a maximum speed of 42μm.s-1 in water. The propulsion mechanism of the Janus motor was attributed to the self-thermophoresis effect： The asymmetric distribution of the gold layer generated a local thermal gradient, which in turn generated thermophoretic force to propel the Janus motor. Such NIR-propelled Janus capsule motors can move efficiently in cell culture medium and have no obvious effects on the cell at the power of the NIR laser, indicating considerable promise for future biomedical applications.展开更多
文摘Light-driven synthetic micro-/nanomotors have attracted considerable attention in recent years due to their unique performances and potential applications. We herein demonstrate the dye-enhanced self-electrophoretic propulsion of light-driven Ti O_2–Au Janus micromotors in aqueous dye solutions. Compared to the velocities of these micromotors in pure water, 1.7, 1.5, and 1.4 times accelerated motions were observed for them in aqueous solutions of methyl blue(10-5g L^(-1)), cresol red(10^(-4)g L^(-1)),and methyl orange(10^(-4)g L^(-1)), respectively. We determined that the micromotor speed changes depending on thetype of dyes, due to variations in their photodegradation rates. In addition, following the deposition of a paramagnetic Ni layer between the Au and Ti O_2 layers, the micromotor can be precisely navigated under an external magnetic field. Such magnetic micromotors not only facilitate the recycling of micromotors, but also allow reusability in the context of dye detection and degradation.In general, such photocatalytic micro-/nanomotors provide considerable potential for the rapid detection and ‘‘on-thefly'' degradation of dye pollutants in aqueous environments.
基金Institute for Advanced Study and School of Material Science and Engineering of Tongji University.L.M.acknowledges the support from National Natural Science Foundation of China (Grant Nos.81501607 and 51875518),as well as the support from Development Projects of Zhejiang Province (Grant No.2017C 1054).
文摘The advancement in the micro-/nanofabrication techniques has greatly facilitated the development of micromotors.A variety of micromotors have been invented with powerful functions,which have attracted a broad range of interests from chemistry, physics,mechanics,biology and medicine.In this paper,we reviewed recent progress in micromotors and highlighted representative works.The mechanisms of micromotors by internal and external energy sources were described.We described general fabrication strategies of the popular micromotors (wire,tubular,helical and Janus)including bottom-up and top-down approaches.In the application section,we primarily focused on the biological applications,such as biological cargo delivery, biosensing and surgery.At last,we discussed the current challenges and provided future prospects.
基金supported by the National Key Research and Development Program of China(2022YFA1105300)the National Natural Science Foundation of China(T2225003,52073060 and 61927805)+3 种基金the Nanjing Medical Science and Technique Development Foundation(ZKX21019)the Clinical Trials from Nanjing Drum Tower Hospital(2022-LCYJ-ZD-01)Guangdong Basic and Applied Basic Research Foundation(2021B1515120054)the Shenzhen Fundamental Research Program(JCYJ20190813152616459 and JCYJ20210324133214038).
文摘Considerable efforts have been devoted to treating gastric ulcers.Attempts in this field tend to develop drug delivery systems with prolonged gastric retention time.Herein,we develop novel Chinese herb pollen-derived micromotors as active oral drug delivery system for treating gastric ulcer.Such Chinese herb pollen-derived micromotors are simply produced by asymmetrically sputtering Mg layer onto one side of pollen grains.When exposed to gastric juice,the Mg layer can react with the hydrogen ions,resulting in intensive generation of hydrogen bubbles to propel the micromotors.Benefiting from the autonomous motion and unique spiny structure,our micromotors can move actively in the stomach and adhere to the surrounding tissues.Besides,their special architecture endows the micromotors with salient capacity of drug loading and releasing.Based on these features,we have demonstrated that our Chinese herb pollen-derived micromotors could effective deliver berberine hydrochloride and show desirable curative effect on the gastric ulcer model of mice.Therefore,these Chinese herb pollen-derived micromotors are anticipated to serve as promising oral drug delivery carriers for clinical applications.
基金supported by the National Key R&D Program of China(Grant No.2022YFB4701200)the National Natural Science Foundation of China(Grant Nos.52335003,52405011 and U22A20176)+3 种基金the Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2022B1515120078 and 2023A1515110313)the Shenzhen Natural Science Fund(the Stable Support Plan Program,Grant No.GXWD20231129161359002)the Shenzhen Science and Technology Program(Grant No.KQTD20210811090146075)Pre-research Task of State Key Laboratory of Robotics and Systems(HIT)(Grant No.SKLRS202421B).
文摘Inspired by the ubiquitous helical structures in nature,research on artificial helices has attracted increasing attention.As a unique and complex three-dimensional(3D)geometry in the microscopic world,the micro-/nano helix has significant advantages in wide applications due to its distinctive properties at the micro-scale.Micro-/nanotechnology is advancing rapidly.The geometric complexity of helical structure poses technical challenges for the manufacturing at the micro-/nanoscale,requiring some emerging manufacturing techniques.In this review,we systematically classify and summarize existing manufacturing methods for micro/nano helical structures and their underlying mechanisms.Based on the unique physical properties of helical structures at the microscale,their latest applications are analyzed across different fields.Finally,we conclude the challenges and future research directions of micro-/nano helices in manufacturing methods and applications.
基金Acknowledgements This work is supported by the National Natural Science Foundation of China （Nos. 21574094 and 21304064）, the Natural Science Foundation of Jiangsu Province （Nos. BK20130292 and BK20150314）, a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions （PAPD）, the Fund for Excellent Creative Research Teams of Jiangsu Higher Education Institutions and the projectsponsored by the Scientific Research Foundation for the returned overseas Chinese scholars, State Education Ministry.
文摘In this study, we report a spindle-like micromotor. This device, which is fabricated using a one-step electrospinning method, consists of biodegradable polycaprolactone and an anionic surfactant. Intriguingly, not only can the resulting micromotor move autonomously on the surface of water for a long period of time （-40 min） due to the Marangoni effect, but it also exhibits a pH sensing behavior due to variations in the surface tension caused by the release of surfactant under different pH conditions. More interestingly, we reveal that the motion-based pH sensing property is size-dependent, with smaller structures exhibiting a higher sensitivity. In addition, since polycaprolactone is a biode- gradable material, the micromotor described in this study can be easily degraded in solution. Hence, features such as one-step fabrication, motion readout, and biodegradability render this micromotor an attractive candidate for sensing algplications.
文摘A new rod-shaped traveling wave ultrasonic micromotor is developed. In the micromotor, five pieces of piezoelectric ceramics clamped by two metal cylinders are used as its stator. The driving principle of the rodshaped ultrasonic motor is simulated. The stator structure and the position to lay these piezoelectric ceramics are calculated to improve the electro mechanical conversion efficiency. A flexible rotor is designed to reduce the radial slip between the stator and the rotor, and to improve the motor efficiency. The prototype motor and its micror driver are tested. The motor is 9 mm in out-diameter, 15 mm in length and 3.2 g in weight. When the motor operates with the first bending frequency （72 kHz） of the stator, its maximal rotational speed and the torque reach 520 r/rain and 4.5 mN · m. Results show that the motor has good stability. The speed fluctuation is controlled within 3% by the frequency automatic tracking technique.
基金supported by the project of Sinopec Key Laboratory of Marine Oil and Gas Reservoir Development(Grant No.SYSKT20240033)with the contract(Grant No.33550000-24-ZC0613-0094)the National Natural Science Foundation of China(Grant No.52405610 and No.52475589)the Fundamental Research Funds for the Central Universities(Grant No.DUT24RC(3)048).
文摘Micro/nanomotors present considerable potential in various fields,such as medical treatment,environmental remediation,and cell engineering.However,their restricted lifetime and issues in navigation control hinder their applications in cases requiring precise positioning without chemical fuels.Thus,we propose a tubular micromotor driven by external magnetic fields,enabling it to swim in water with accurate transport capabilities.The presented tubular micromotor incorporates a single-sided base,which increases the contact area to enable cargo delivery in liquid environments.The micromotor exhibits varied movement behaviors by applying different magnetic fields,and frequency modulation allows for control over movement velocity.Template-assisted electrochemical deposition is employed to achieve large-scale fabrication,which enables the construction of Ni–Au tubular micromotors with a single-sided base.In addition,the micromotor can trace a predefined path,which demonstrates its precise positioning ability.The cargo transport capability of the micromotor is further validated using polystyrene globules as cargo.This fuel-free tubular micromotor,which is driven by magnetic fields,provides a promising approach for precise cargo delivery.Its broad feasibility makes it suitable for various biomedical applications.
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2008AA04Z312)National Natural Science Foundation of China (Grant No. 50577036)
文摘The modeling and evaluation of a prototype rotary micromotor where the annular rotor is supported electrostatically in five degrees of freedom is presented in order to study the behavior of this levitated micromotor and further optimize the device geometry. The analytical torque model is obtained based on the principle of a planar variable-capacitance electrostatic motor while the viscous damping caused by air film between the stator and rotor is derived using laminar Couette flow model. Simulation results of the closed-loop drive motor, based on the developed dynamic model after eliminating mechanical friction torque via electrostatic suspension, are presented. The effects of the high-voltage drive, required for rotation of the rotor, on overload capacity and suspension stiffness of the electrostatic bearing system are also analytically evaluated in an effort to determine allowable drive voltage and attainable rotor speed in operation. The analytical results show that maximum speed of the micromotor is limited mainly by viscous drag torque and stiffness of the bearing system. Therefore, it is expected to operate the device in vacuum so as to increase the rotor speed significantly, especially for those electrostatically levitated micromotors to be used as an angular rate micro-gyroscope.
基金supported by the National Natural Science Foundation of China(Grant No.21304064)the Natural Science Foundation of Jiangsu Province(Grant No.BK20130292)+2 种基金a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Fund for Excellent Creative Research Teams of Jiangsu Higher Education Institutionsthe project-sponsored by SRF for ROCS,SEM
文摘In this paper, we report fabrication of the bimetallic Janus microsphere, a magnesium microsphere with a silver surface coating, through thermal evaporation technique. Because of the Janus structure, this micromotor can be propelled in two different directions by the surface silver or magnesium ‘engine' and hydrogen peroxide or water fuel. In addition, due to the bactericidal property of silver, this autonomous micromotor is capable of killing bacteria in solution. As compared to the static one, the micromotor is able to kill the bacteria at a much faster rate(about nine times of that of the static one),demonstrating the superiority of the motion one. We thus believe that the micromotor shown in the current study is potentially attractive for the environmental hygiene applications.
基金This work was supported by the National Natural Science Foundation of China(No.51472115)the Jiangsu Provincial Graduate Research Innovation and Practice Project(KYCX17_0672,KYCX19_0645)+1 种基金the Research Program of Natural Science in Huaian(HAB201717)and the Jiangsu Overseas Research&Training Program for University Young Faculty and Presidents.
文摘Biocompatible designed micromotor has attracted more and more concerns in the field of biomedicine due to their self-propulsion and delivery abilities.Such micromotors,mostly consisting of alkali earth metals,hydrogels,or other motile biomaterials,can effectively transform chemical energy into mechanical or kinetic energy to achieve the expected delivery of cargos to the sites of action.Except for conveying power,the modifiable surface and inner cavity of micromotors guarantee that their potential as versatile delivery systems for therapeutic agents.Here,this review generalizes the propelling mechanisms,composites,and shapes of micromotors.Besides,the application of micromotor-derived composites for biomedicine delivery and other versatile purposes are also discussed.
基金the Fundamental Research Funds for the Central Universities(WUT:2019III075GX)the Open Foundation of Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics(Grant No.TAM201813).
文摘Micromotors are widely used in cell operation,drug delivery and environmental decontamination due to their small size,low energy consumption and large propelling power.Compared to traditional Janus micromotor,the shell Janusmicromotor has better motion performance.However,the structural optimization of itsmotion performance is still unclear.The main factor restricting the motion performance of shell Janus micromotors is the drag forces.In the current work,theoretical analysis and numerical simulation were applied to analyze the drag forces of shell Janus micromotors.This study aims to design the optimum structure of shell Janus micromotors with minimum drag forces and obtain the magnitude of drag forces considering both the internal and external fluids of the shell Janus micromotors.Moreover,the influence of the motor geometry and Reynolds number on the drag coefficient was analyzed using numerical simulations.The results provide guidance for the optimum flow velocity,opening diameter and shell thickness to achieve minimum drag force.
文摘A 1 mm diameter electromagnetic micromotor was developed as a crux component for MEMS application. The motor has a novel layer structure with a 1 mm diameter rotor in the middle of two stators with the same size. The stator uses multiple layers, slotless and concentrated planar winding. The rotor adopts multipolar permanent magnet with high performance. Ruby bearing is used to prolong operating lifetime of the micromotor. The stator winding, consisting of 6 layer coils, 42 turns, and 9 pairs, is fabricated with microprocessing techniques. The micromotor has long operation lifetime, its running speed is stable and controllable, and rotational direction can be easily reversed. Maximum achieved rotational speed of 18000 r/min with maximum output torque of 1.5 μ N·m has been obtained. This paper presented the key technology for developing this kind of micromotor including the design of structure, magnetic circuit, heat problem, friction improvement, microprocessing techniques, and so on.
基金the National High Technology Re-search and Development Program (863) of China(No. 2003AA404210, 2005AA404250, 2003AA404210,2006AA01Z443)
文摘A multi-try counter-meshing gears (CMG) discrimination device based on micro electromechani-cal system (MEMS) technology was designed for some specified information fields. The discrimination device consists of two groups of metal CMG, two pawl/ratchet mechanisms, two driving micromotors and two re-setting micromotors, which make the CMG withdraw by raising the pawls. The energy-coupling element is a photoelectric sensor with a circular plate which is notched. Micromotor is fabricated using the ultraviolet LiGA (UV-LiGA) fabrication process and precision mechanical engineering. The discrimination device has the function which can automatically reset, with the correct resetting code, it can be tried another times.
基金supported in part by the National Science Foundation(IIS1318638 and IIS1426752)the Shenzhen Science and Technology Project(ZDSY20120617113312191)
文摘This paper presents the formulation and practical implementation of positioning methodologies that compensate for the nonholonomic constraints of a mobile microrobot that is driven by two vibrating direct current(DC) micromotors. The open-loop and closed-loop approaches described here add the capability for net sidewise displacements of the microrobotic platform. A displacement is achieved by the execution of a number of repeating steps that depend on the desired displacement, the speed of the micromotors, and the elapsed time. Simulation and experimental results verified the performance of the proposed methodologies.
基金supported in part by the National Science Foundation(NSF)grants 1739308(R.E.T.)2132886(R.E.T.),NSF GREP DGE1745016/DGE2140739(T.I.)a seed grant from the Carnegie Mellon University Manufacturing Futures Institute(R.E.T.and S.B.).
文摘CONSPECTUS:The concept of micrometer-scale swimming robots,also known as microswimmers,navigating the human body to perform robotic tasks has captured the public imagination and inspired researchers through its numerous representations in popular media.This attention highlights the enormous interest in and potential of this technology for biomedical applications,such as cargo delivery,diagnostics,and minimally invasive surgery,as well as for applications in microfluidics and manufacturing.To achieve the collective behavior and control required for microswimmers to effectively perform such actions within complex,in vivo and microfluidic environments,they must meet a strict set of engineering criteria.These requirements include,but are not limited to,small size,structural monodispersity,flexibility,biocompatibility,and multifunctionality.Additionally,microswimmers must be able to adapt to delicate environments,such as human vasculature,while safely performing preprogrammed tasks in response to chemical and mechanical signals.Naturally information-bearing biopolymers,such as peptides,RNA,and DNA,can provide programmability,multifunctionality,and nanometer-scale precision for manufactured structures.In particular,DNA is a useful engineering material because of its predictable and well-characterized material properties,as well as its biocompatibility.Moreover,recent advances in DNA nanotechnology have enabled unprecedented abilities to engineer DNA nanostructures with tunable mechanics and responsiveness at nano-and micrometer scales.Incorporating DNA nanostructures as subcomponents in microswimmer systems can grant these structures enhanced deformability,reconfigurability,and responsiveness to biochemical signals while maintaining their biocompatibility,providing a versatile pathway for building programmable,multifunctional microand nanoscale machines with robotic capabilities.In this Account,we highlight our recent progress toward the experimental realization of responsive microswimmers made with compliant DNA components.We present a hybrid top-down,bottom-up fabrication method that combines templated assembly with structural DNA nanotechnology to address the manufacturing limitations of flexibly linked microswimmers.Using this method,we construct microswimmers with enhanced structural complexity and more controlled particle placement,spacing,and size,while maintaining the compliance of their DNA linkage.We also present a novel experimental platform that utilizes two-photon polymerization(TPP)to fabricate millimeter-scale swimmers(milliswimmers)with fully customizable shapes and integrated flexible linkers.This platform addresses limitations related to population-level heterogeneity in micrometer-scale systems,allowing us to isolate the effects of milliswimmer designs from variations in their physical dimensions.Using this platform,we interrogate established hydrodynamic models of microswimmer locomotion and explore how design and actuation parameters influence milliswimmer velocity.We next explore opportunities for enhancing microswimmer responsiveness,functionality,and physical intelligence through the inclusion of nucleic acid subcomponents.Finally,we highlight how our parallel research on xeno nucleic acids and interfacing DNA nanotechnology with living cells can enable the creation of fully organic,truly biocompatible microswimmers with enhanced functionality,improving the viability of microswimmers for applications in healthcare,manufacturing,and synthetic biology.
基金supported by the National Basic Research Foundation(Grant No.5140508A0501).
文摘Traditional gyrocompasses,while capable of providing autonomous directional guidance and path correction,face limitations in widespread applications due to their large size,making them unsuitable for compact devices.Microelectromechanical system(MEMS)gyrocompasses offer a promising alternative for miniaturization.However,current MEMS gyrocompasses require the integration of motor rotation modulation technology to achieve high-precision north-finding,whereas conventional motors in previous research introduce large volume and residual magnetism,thus undermining their size advantage.Here,we innovatively propose a miniature MEMS gyrocompass based on a MEMS traveling-wave micromotor,featuring the first integration of a chip-scale rotational actuator and combined with a precise multi-position braking control system,enabling high accuracy and fast north-finding.The proposed gyrocompass made significant advancements,reducing its size to 50×42.5×24.5 mm^(3)and achieving an azimuth accuracy of 0.199°within 2 min,which is half the volume of the smallest existing similar devices while offering twice the performance.These improvements indicate that the proposed gyrocompass is suitable for applications in indoor industrial robotics,autonomous driving,and other related fields requiring precise directional guidance.
基金supported by the National Natural Science Foundation of China (Grant Nos.22171058 and 21871069)the Fundamental Research Funds for the Central Universities (Grant No.HIT.OCEF.2021027)。
文摘The biointerface engineering of living cells by creating an abiotic shell has important implications for endowing cells with exogenous properties with improved cellular behavior,which then boosts the development of the emerging field of living cell hybrid materials.Herein,we develop a way to perform active nanoencapsulation of single cell,which then endows the encapsulated cells with motion ability that they do not inherently possess.The emerging motion characteristics of the encapsulated cells could be self-regulated in terms of both the motion velocity and orbits by different proliferation modes.Accordingly,by taking advantage of the emergence of differentiated moving abilities,we achieve the self-sorting between mother cells and daughter cells in a proliferated Saccharomyces cerevisiae cell community.Therefore,it is anticipated that our highlighted study could not only serve as a new technique in the field of single-cell biology analysis and sorting such as in studying the aging process in Saccharomyces cerevisiae,but also open up opportunities to manipulate cell functionality by creating biohybrid materials to fill the gap between biological systems and engineering abiotic materials.
基金supported by the National Natural Science Foundation of China (21425519)the Tsinghua University Startup Fund
文摘"Active" components can be introduced into a passive system to completely change its physical behavior from its typical behavior at thermodynamic equilibrium. To reveal the interaction mechanisms between individuals, researchers have designed unique self-propelled particles to mimic the collective behavior of biological systems. This review focuses on recent theoretical and experimental advances in the study of self-propelled particle systems and their individual and collective behaviors. The potential applications of active particles in chemical, biological and environmental sensing and single particle imaging are discussed.
基金Beijing Institute of Technology Teli Young Fellow Program,Grant/Award Number:3320012222218Beijing Institute of Technology Research Fund Program for Young Scholars,Grant/Award Number:1750023022215+3 种基金National Natural Science Foundation of China,Grant/Award Numbers:32101062,32071341Guangdong Basic and Applied Basic Research Foundation,Grant/Award Numbers:2019A1515110005,2022A1515012607Fundamental Research Funds for the Central UniversitiesSun Yat-sen University。
文摘Micro/nanorobots are promising for a wide range of biomedical applications(such as targeted tumor,thrombus,and infection therapies in hard-to-reach body sites)because of their tiny size and high maneuverability through the actuation of external fields(e.g.,magnetic field,light,ultrasound,electric field,and/or heat).However,fully synthetic micro/nanorobots as foreign objects are susceptible to phagocytosis and clearance by diverse phagocytes.To address this issue,researchers have attempted to develop various cytomembrane-camouflaged micro/nanorobots by two means:(1)direct coating of micro/nanorobots with cytomembranes derived from living cells and(2)the swallowing of micro/nanorobots by living immunocytes via phagocytosis.The camouflaging with cytomembranes or living immunocytes not only protects micro/nanorobots from phagocytosis,but also endows them with new characteristics or functionalities,such as prolonging propulsion in biofluids,targeting diseased areas,or neutralizing bacterial toxins.In this review,we comprehensively summarize the recent advances and developments of cytomembrane-camouflaged medical micro/nanorobots.We first discuss how cytomembrane coating nanotechnology has been employed to engineer synthetic nanomaterials,and then we review in detail how cytomembrane camouflage tactic can be exploited to functionalize micro/nanorobots.We aim to bridge the gap between cytomembrane-cloaked micro/nanorobots and nanomaterials and to provide design guidance for developing cytomembrane-camouflaged micro/nanorobots.
基金This work was financially supported by the National Natural Science Foundation of China （No. 21573053）. The project was supported by State Key Laboratory of Advanced Technology for Materials Synthesis and Processing （Wuhan University of Technology）.
文摘We report a fuel-free, near-infrared （NIR）-driven Janus microcapsule motor. The Janus microcapsule motors were fabricated by template-assisted polyelectrolyte layer-by-layer assembly, followed by spraying of a gold layer on one side. The NIR-powered Janus motors achieved high propulsion with a maximum speed of 42μm.s-1 in water. The propulsion mechanism of the Janus motor was attributed to the self-thermophoresis effect： The asymmetric distribution of the gold layer generated a local thermal gradient, which in turn generated thermophoretic force to propel the Janus motor. Such NIR-propelled Janus capsule motors can move efficiently in cell culture medium and have no obvious effects on the cell at the power of the NIR laser, indicating considerable promise for future biomedical applications.
