Fabrication And Locomotion Control Of Biomedical Micro-/Nanomotor

Micro/nanomotor ia a kind of artificial micro and nano devices which can transform chemical energy,optical energy,electric energy and other energy into mechanical energy or movement to achieve self-propulsion.With the advantages of lightweight,less volume,high thrust and low power,micro/nano motor can be widely used in the field of sensing detection,nanofabrication,self-assembly and nano-propulsion.Especially,micro/nanomotor can serve as promising biomimetic nanomotor for biomedical and nanoelectronical applications.However,most of these micro/nanomotor still have some limitations,including complex preparation technology and difficulty of motion control.Hence,the accurate motion cotrol and high-efficient propulsion are essential for micro/nanomotor applied in the field of biomedicine.In this thesis,the research is focus on the new propulsion method,motion control method and application.A chemically powered catalytic nanomotors,composed of conductive Au/Pt spherical Janus particles,can autonomously detect and repair microscopic mechanical defects to restore the electrical conductivity of broken electronic pathways.The Janus micromotor can move at the speed of 36.8 μm/s in 15% H2O2 solution.This repair mechanism capitalizes on energetic wells and obstacles formed by surface cracks,which dramatically alter the nanomotor dynamics and trigger their localization at the defects.By developing models for self-propelled Janus nanomotors on a cracked surface,we simulate the systems’ dynamics over a range of particle speeds and densities to verify the process by which the nanomotors autonomously localize and accumulate at the cracks.The janus micromotor is also can be used for optical scanning and imaging.The microromotors are made of high-refractive-index microsphere lenses and powered by local catalytic reactions to swim and scan over the sample surface.Autonomous motion and magnetic guidance of microrobots enable large-area,parallel and nondestructive scanning with subdiffraction resolution,as illustrated using soft biological samples such as neuron axons,protein microtubulin,and DNA nanotubes.A chemical propelled multilayer microrocket can be fabricated by templated-assissted electrodeposition technique and layerby-layer self assembly method.The multilayer microrocket can move at the speed of 1280 μm/s in 15% H2O2 solution.Futhermore,the motion of microrockets at any required direction can be obtained by controling the orientation of the applied mag netic field while the microrocket is propelled chemically.Functionalization of polymeric multilayer s to the microrocket allows for absorbing organic pollutants,the removals methyl-paraoxon and Rhodamine 6G are 75% and 95%,respectively.the flexible biomimetic magnetic nanomotor can be faricated by template-assisted electrodeposition technique and nanoetching method.The effect of accurated frequency,locomotion environment,geometrical parameters and other parameters on the motion of nanomotors are studied experimentally and numerically.The fish-like nanoswimmer reaches its fastest speed of 30.97 μm/s using a frequency of 11 Hz.In order to optimize the propelled efficiency of nanobot,another free-style nanomotor which consist a gold segment as head and two nickel segments as arms with two porous silver hinges linking each segment.The free style nanoswimmer reaches its fastest speed of 59.39 μm/s.a fuel-free hybrid nanomotors,which comprise a magnetic helical structure and a concave nanorod end,are synthesized using a template-assisted electrochemical deposition process followed by segment-selective chemical etching.The effect of accurated frequency,locomotion environment,geometrical parameters and other parameters on the motion of nanomotors are studied experimentally.Dynamic switching of the propulsion mode with reversal of the movement di rection and digital speed regulation are demonstrated on a single nanovehicle.These hybrid nanomotors exhibit a diverse biomimetic collective behavior,including stable aggregation,swarm motion,and swarm vortex,triggered in response to different field inputs.Such adaptive hybrid operation and controlled collective behavior hold considerable promise for designing smart nanovehicles that autonomously reconfigure their operation mode according to their mission or in response to changes in their surrounding environment or in their own performance,thus holding considerable promise for diverse practical biomedical applications of fuel-free nanomachines.An micro/nanomotor autonomous navigation based on image recognition technique and fuzzy control method is investigated.This system is consist of industrial camera,autonomous navigation system,magnetic control system and electromagnet system.Based on this autonomous navigation system,the micro/nanomotor can autonomously avoid the barriers.This system can control the micro/nanomotor autonomously locomote in the condition with single barrier,multipath barrier,multidestination barrier,simple maze or complex maze.In summary,we believe tha micro/nanomotor studied in this paper will widely be used in the field of micro-driven and micro-positioning and have a very good application prospect,because of their unique properties and advantages.