  Nematodes have evolved to swim in highly viscous environments. Artificial
mechanisms that mimic the locomotory functions of nematodes can be efficient
viscous pumps. We experimentally simulate the motion of the head segment of
Caenorhabditis elegans by introducing a reciprocating and rocking blade. We
show that the bio-inspired blade's motion not only induces a flow structure
similar to that of the worm, but also mixes the surrounding fluid by generating
a circulatory flow. When confined between two parallel walls, the blade causes
a steady Poiseuille flow through closed circuits. The pumping efficiency is
comparable with the swimming efficiency of the worm. If implanted in a sealed
chamber and actuated remotely, the blade can provide pumping and mixing
functions for microprocessors cooled by polymeric flows and microfluidic
devices.
