Motion Analysis of Micropart in Dry Friction Environment Due to Surface Excitation Considering Microscale Forces

This manuscript investigates the motion of a micropart on a dry nonlubricated controlled deformable surface considering the dynamically changing microforces while in contact with the surface. The motion analysis of a micropart on a flexible surface under controlled deformation is the first step to initiate feasibility of a micromanipulation device. At the micro/nanoscale, the surface force of attraction becomes more significant than the inertia force; thus motion analysis requires estimating and accommodating these forces in a dynamic model. The model considers microscale forces and surface roughness conditions (asperity deformation), while dynamically evaluating the friction coefficient and attraction force due to the dynamic asperity deformation as the micropart moves on a controlled deformation active surface. The parameters considered in the model include the micropart mass and size, the relative roughness between the micropart and surface, the surface and micropart material, and input actuator frequency, stroke, and deformation profile. The simulation results indicate that predictable micropart motion could be achieved but only within a certain range of input actuator frequencies. At lower frequencies no motion is possible while at higher frequencies the micropart detaches from the surface. The understanding of the effects of the microforces on the dynamic model and micropart motion would pave the way towards controlled micropart translocation and manipulation employing a flexible surface for microassembly or for processes requiring controlled micropart handling for heterogeneous microdevice mass production.