Several billion dermal display nanorobots residing in the epidermis of a human hand can be used as display screens to access real-time physiological information or other stored data, as described byĀ Robert FreitasĀ inĀ Section 7.4.6.7Ā ofĀ Nanomedicine, Vol. I. In this second of four images, the activated screen is almost fully visible, displaying a schematic image of the concentration and kinds of nanorobots currently present in the userās bloodstream.