Research On Self-actuating Pt Micronanorobots Dynamics

Micronanorobots have attracted interest in potential application of medical treatment,biological engineering,environmental protection and so on.Beside previous applications,micronanorobots based drug delivery system for cancer target therapy has developed rapidly in recent years.Radiotherapy and chemotherapy and target therapy is harmful to normal cells.The target therapy based on biocompatible micronanorobots could deliver drug to cancer cells with high precision.In micronanorobots research infancy,some traditional theories are not suitable for micronanorobots because of scale effect formed by micronanorobots micro size(less than 100 ?m).Micronanorobots' two categories classified by driving mode and control methods:external driving micronanorobots and self-actuating micronanorobots.External driving micronanorobots request high quality equipment and observation instruments such as Computed Tomography(CT)which is harmful radiation to normal cells.Self-actuating micronanorobots have attracted interest because of these advantages such as non-extenal field,simple fabrication,low cost and so on.The thesis researched on platinum(Pt)self-actuating micronanorobots motion mechanism based on chemistry self-actuating theory in H2O2 solution,it aimed at applying to targeted therapy for cancer.Based on micromechanics and scale effect,the gravity of micronanorobots could be ignored because the gravity is much less than viscous force.Brown force is random force,so it only changed the direction of motion.Therefore,the resistance force is viscous force.Based on driving,movement principle and above analysis modeled the motion of micronanorobots:rectilinear motion of Pt/Au hybrid rod shape micronanorobot(Au to Pt direction);rotary of Pt/Au hybrid Z shape micronanorobot;single Pt A shape micronanorobot had no motion because of force balance;circular motion of single Pt V shape micronanorobot.The fabrication is based on Focused Ion beam(FIB)and plasma sputtering.The Energy Dispersive X-ray Detector(EDX)in Scanning Electron Microscope(SEM)was used to detect the layer purity of metal.The purities of Pt and Au were 94.28wt%and 84.75wt%,respectively.Experimental operating platform consisting of micro-operation workbench and visual tracking feedback platform aimed at solving the difficulties on operation,release and tracking.Reliable operation,release and tracking would be realized by the double manipulators and vibration release method.Following results obtained by the experiments:Pt/Au hybrid rod shape micronanorobots maximum velocity was 4 ?m/s the maximum rotation speed of Pt/Au hybrid Z shape micronanorobot was 19 rpm;Single Pt A shape micronanorobots experimental results was consistent with the theoretical analysis(no motion);the maximum linear velocity and equivalent diameter of 90° single Pt V shape micronanorobots was 3.42 ?m/s and 37.1?m,respectively;135° single Pt V shape micronanorobots had no circular motion.The driving force could be estimated based on Stoke Viscous Law,Newton's Second Law,four micronanorobots' motion model and results in thesis.The order magnitude of driving force was from 10-4HN to 10-13N.This thesis presented the theoretical design and excremental results of micronanorobot,which lays a good foundation for future research and applications.