Multi-directional Characterization for Pollen Tubes Based on a Nanorobotic Manipulation System.

Pollen tubes’ main function is to transport gametes to ovules. Mechanical properties of pollen tubes affect their growth and penetration. Most existing systems for characterizing pollen tubes can only characterize pollen tubes from one direction. However, considering pollen tubes’ nonuniform properties, results got from one fixed direction don’t necessarily represent pollen tubes’ overall properties. In order to characterize pollen tubes from multi-direction instead of one direction, a nanorobotic system is proposed herein. The system contains two robots, robot 1 for sample assembly and robot 2 for sensor assembly. Robot 1’s rotation degree enables pollen tubes to be characterized from multi-direction. During experiments, the pollen tube is bent at different angles from 0° to 360°. Bending forces at different angle are quite different. The results demonstrate that pollen tubes are inhomogeneous along circumferential direction and justify the necessity to characterize pollen tubes from multi-direction. Experiment results can be used to measure pollen tubes’ stiffness at different direction and analyze how pollen tubes penetrate through pistil.