Say what you will about these sperm-like bio-bots; they've got heart. The beating of live heart cells propels a tail back and forth, so that these self-powered swimming bio-bots—the first of their kind—could one day wriggle through your body delivering drugs. No batteries needed.
The design, published this week in the journal Nature Communications, is simple. The head and tail are made of a synthetic polymer coated with a protein that let heart cells attach to it. Those cells—as heart cells do—beat, creating a wave that propagates down the tail. In bacteria and sperm, this tail is called a flagella, and whipping it back and forth thrusts the cell, or in this case, bio-bot forward. The researchers also created a two-tailed bio-bot capable of swimming faster at 81 micrometers per second.
The same research group at the University of Illinois had previously created a 3D-printed hydrogel bio-bot powered also by cardiac cells that "walks." These new swimming bio-bots are much smaller and use a different mechanism to move.
Other researchers have created nanobots actually powered by sperm cells themselves and guided by magnets. The synthetic body and heart cell-power design, however, could offer more flexibility in the future, such as one day becoming "intelligent." Adding neurons that detect specific molecules, such as glucose or a toxin, could turn these bio-bots into sensors. Now that's a robot with both brains and heart. [Nature Communications via IEEE Spectrum]