  A major role of robots is to assist in assembly by moving building blocks and
by exerting forces, e.g. to snap parts together. At the molecular scale,
diffusive transport and thermal forces permit self-assembly, and molecular
robots can only accelerate the process by performing work. This raises the
question if - similar to Landauer's principle in computing - there is a lower
limit to the work done by a robot for a given acceleration of an assembly
process. Here, a brief analysis suggests that a doubling of a reaction rate by
robotic manipulation requires at least kBTln2 in energy expenditure, either to
perform mechanical work or to erase information.
