AFM-based manipulation modeling of bacillus subtilis bioparticles using finite element method

Since bioparticles experience large deformations, it is imperative to develop an appropriate model for particle modeling based on its size to prevent Nano biological particle destruction such as Bacillus, which is modeled as a Nano-beam. In this paper, models with large deformation assumptions were suggested for a longitudinal particle that can be geometrically considered as a beam. By modeling a nano/microparticle using continuum mechanics theory and dynamic simulation based on FEM, the dynamic behavior and shape deformation caused by the manipulation forces were examined. Hence, the manipulation of bioparticles with a cylindrical shape, named Bacillus Subtilis, was investigated. Critical time and forces and the predominant mode of movement of biological nanoparticles in a manipulation process were obtained and the Euler–Bernoulli theory was utilized to investigate the dynamic of biological nanoparticles. After the discretization of governing equations of motion using the Galerkin method, mass and stiffness matrices were extracted and critical forces were calculated to examine the dynamic behavior of particles. The effect of the aspect ratio showed that the deformation of the particle increases with increasing aspect ratio. In addition, the manipulation force is an essential parameter when small and large deflection models are compared. It was evident that the difference between linear and nonlinear deflection models at L/D = 100 was decreased from 39.47% for the 10 µN force to 12.46% for the 5 µN force. It was deduced that the small and large deflection models tend to have similar results with reducing force.