Engineers have created a group of first tiny, synthetic bio-bots that can swim on their own, helped by the power of heart cells, and traverse the viscous fluids of biological environments.
Taher Saif, from the University of Illinois Gutgsell, who led the study, said that micro-organisms have a whole world that we only glimpse through the microscope, and this is the first time that an engineered system has reached this underworld.
The bio-bots are modeled after single-celled creatures with long tails called flagella - for example, sperm. The researchers begin by creating the body of the bio-bot from a flexible polymer.
Then they culture heart cells near the junction of the head and the tail. The cells self-align and synchronize to beat together, sending a wave down the tail that propels the bio-bot forward.
This self-organization is a remarkable emergent phenomenon, Saif said, and how the cells communicate with each other on the flexible polymer tail is yet to be fully understood. But the cells must beat together, in the right direction, for the tail to move.
Saif said that the bots require minimal amount of engineering - just a head and a wire, where the cells come in, interact with the structure, and make it functional.
The team also built two-tailed bots, which they found can swim even faster. Multiple tails also opens up the possibility of navigation.
The study is published in the journal Nature Communications.