Engineers are pioneering a new way to explore the viscous fluids of biological environments, like the inside of the human body, where microscopes are difficult to place. Called a “bio-bot,” the microscopic biological machine swims like a sperm, is powered by heart cells, propelled by a tail and can navigate the aquatic world of micro-organisms on its own.
Researchers from the University of Illinois, led by Taher Saif, a professor of mechanical science and engineering, are part of an emerging science that uses cells to communicate with each other and drive a synthetic organism forward. Their study, published in the journal Nature Communications, marks an “exciting advance," they say, in self-propelled biological robots.
"Micro-organisms have a whole world that we only glimpse through the microscope," Saif said in a statement. "This is the first time that an engineered system has reached this underworld."
The bio-bot, modeled after single-celled creatures with long tails, called flagella, is the first synthetic structure that can travel the channels of a biological environment unsupervised. The body of the bio-bot is made of a flexible polymer. Heart cells, or cardiomyocytes, are cultured at the head and tail of the synthetic organism. These cells, contract which sends a beat, or energy, down the bot’s body and propels it forward.
"It's the minimal amount of engineering - just a head and a wire," Saif said. "Then the cells come in, interact with the structure, and make it functional."
Here’s a video, provided in a press release, of how the bio-bot works:
What are the applications of a microscopic bio-bot? Researchers say cell-powered bio-bots could be used to sense chemicals or target certain kinds of cells, such as cancer cells, inside a biological environment.
"The long-term vision is simple," Saif said. "Could we make elementary structures and seed them with stem cells that would differentiate into smart structures to deliver drugs, perform minimally invasive surgery or target cancer?" That’s the scientists’ hope.
This isn’t the first time researchers have developed a bio-bot from living, active cells. In 2012, researchers also from the University of Illinois built an autonomous robot made from both plastic and living cells from the heart of a rat. The motion of the “walking” bio-bot was created by the contraction and relaxation of the heart cells.
Researchers claimed the 2012 bio-bot could be used to climb walls or detect chemicals in water.