"Hollywood did that, but we are in academic"

I need to use the attraction force exactly, it is simulation model instead of 'look like'.
force = A exp( (x1-x2)^2 + (y1-y2)^2 ) / (2 delta^2)
The force should have affect in all the field instead of only around the votex. For every nano bead, the next position = present position + Gaussionrand() + distance generated by the attraction force. This is the solution I was worring about. "What's the hell going on....". shame.
The yellow beam can be moved automatically with different velocity, it can catch the bead and sometimes it will lose the bead. Why are the initial positions of the beads the same? wired.