On top of that, the mechanics of picking and placing components is completely different at microscales. Overcoming the force of gravity becomes irrelevant compared with dealing with the Van der Waals forces between microscopic particles and such other physical effects as humidity. On the other hand, the person using the system must be able to see what he or she is doing, one way or another. For vision, therefore, the Japanese system uses two microscopes, one optical and the other a scanning electron microscope. Searching an area as small as a square centimeter can take a long time when using a window only a few microns wide.
Depth perception becomes another issue.
In order to allow the user to understand the space in three dimensions, the work area can be rotated with respect to the microscopes. Showing different angles lets the operator pick up parallax information that the eye requires to make sense of a 3-D scene. To increase the realistic feel of macroscopic objects, the human controller uses a pencil with force feedback to move objects. Supplying the nervous system with scaled-up force information has proven vital for dealing with such tiny, delicate objects. As in everyday situations, touch is able to fill in when vision is not quite adequate.