Scientists have developed a sperm-like biological "bot" that can self-propel through viscous environments such inside of the human body, where microscopes are difficult to place.
The biobots are modelled 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 synchronise to beat together, sending a wave down the tail that propels the bio-bot forward.
This self-organisation is a remarkable emergent phenomenon and how the cells communicate with each other on the flexible polymer tail is yet to be fully understood, Saif said.
But the cells must beat together, in the right direction, for the tail to move, researchers said.
"Micro-organisms have a whole world that we only glimpse through the microscope. This is the first time that an engineered system has reached this underworld," lead researcher Taher Saif from the University of Illinois said.
"It's the minimal amount of engineering - just a head and a wire. Then the cells come in, interact with the structure, and make it functional," Saif said.
The team also built two-tailed bots, which they found can swim even faster. Multiple tails also opens up the possibility of navigation.
The researchers envision future bots that could sense chemicals or light and navigate towards a target for medical or environmental applications.
