Nanorobots (shown in light green and blue) adhered to blood vessel walls incorporate a hollow tip projecting out into the vascular lumen, allowing other passing nanorobots (shown as spheres in dark green) to dock with them and exchange information or materials.Ā Notice to Commercial Publishers: The artist Tim Fonseca requires the payment of a non-negotiable $200 fee for each usage of any of his images, for publication.