Meet Anthrobot, the Living Robot

In 2020, a ground-breaking achievement in science news captured the attention of keen readers -the creation of the first living robots, known as xenobots, using stem cells extracted from a frog species called Xenopus laevis. These programmable organisms, each smaller than a millimetre, exhibited remarkable capabilities such as walking, swimming, enduring weeks without sustenance, collective movement, and even self-healing. Eventually, they decomposed and disappeared. Joshua Bongard, a researcher from the collaborative study conducted by the University of Vermont and Tuft University’s Allen Discovery Centre, describes them as “neither a traditional robot nor a known species of animal. It’s a new class of artefact: a living, programmable organism.”

Now, the scientific minds behind the xenobots are embarking on a more ambitious project—anthrobots. These humanoid robots, deriving their name from “anthro-” meaning “human” in Greek, are diminutive “living robots” created from human cells.

Unlike conventional robots with mechanical and electronic components, biological robots, or biobots, originate from living beings. Typically genetically modified into specific forms, these programmable entities consist of cells. (Science fiction lovers would recall thT the term “robot” was coined by Czech writer Karel Capek in his play Rossum’s Universal Robots in 1920).

Initially uncertain whether cells other than those from frogs could be used to create biobots, the researchers successfully realised the anthrobot concept by employing tracheal cells sourced from adult humans. The question is: why are scientists constructing living robots?

Xenobots showcase a range of potential functions, from cleaning radioactive waste and collecting microplastics in oceans to addressing vascular plaques and delivering drugs within the human body. Their ability to survive in environments akin to the human body for days to weeks holds promise for medicinal applications in particular. “”If we could make 3D biological form on demand, we could repair birth defects, reprogram tumours into normal tissue, regenerate after traumatic injury or degenerative disease, and defeat aging,” the researchers say. Anthrobots, the siblings of xenobots, may prove more successful in medicine, given their ability to be produced directly from adult human cells without genetic intervention.

Dr. Gizem Gümüşkaya, a researcher, elucidates in an article published in Advanced Science on November 30, 2023, “We wanted to probe what cells can do besides create default features in the body. By reprogramming interactions between cells, new multicellular structures can be created, analogous to the way stone and brick can be arranged into different structural elements like walls, archways, or columns.” Another notable feature of anthrobots compared to xenobots is that they can self-assemble in laboratory dishes, eliminating the need for cutting and assembling cells.

Tracheal cells, responsible for trapping foreign particles in the windpipe and resembling a human arm, are the primary source of anthrobots. These cells, donated by adult humans for research purposes, were multiplied in the laboratory to form random spherical structures called organoids. These organoids were then programmed to develop hairs on their outer surface, enabling movement. The paddle-like hairs facilitated independent movement in a liquid medium, exhibiting various patterns. When these organoids were combined in a petri dish, they autonomously formed larger structures termed “superbots.”

An unexpected outcome emerged when superbots, placed on damaged human nerve cells, triggered a process leading to self-replication of the nerve cells. Within three days, the damaged nerve cells fully recovered. Michael Levin, a researcher, expresses surprise, stating, “It is fascinating and completely unexpected that normal patient tracheal cells, without modifying their DNA, can move on their own and encourage neuron growth across a region of damage.”

As the potential of these miniature biobots unfolds, their applications are poised to diversify. Theoretically, anthrobots could be employed in treating various diseases such as spinal cord or retinal damage, identifying cancerous cells, clearing blocked arteries, or precisely applying drugs in the body. Concepts like tissue engineering, once confined to the realm of dreams, are now becoming a reality in laboratories. The potential applications are envisioned to extend further by combining different cell types and stimuli, including applications in sustainable building materials and contributing to space exploration.