Nanorobots in Medicine

How do we build something smaller than a human cell, yet intelligent enough to act inside our bodies?

The answers are emerging slowly, pulled together from the edges of quantum physics, synthetic biology, nanochemistry, and bioengineering.

If this is your first time hearing about nanorobots, you're not alone. Most people haven't caught up yet. But those working in this field are already dreaming far ahead: targeted drug delivery, self-repairing tissues, and even intracellular diagnostics. So today, we zoom in—way in—and begin exploring a world you’ll probably never see with your eyes, but may one day rely on to save your life.

Welcome to the hidden universe of nanorobots.

Scientific Perspective

Nanorobotics is an emerging field where robotics and nanotechnology converge, blending engineering, materials science, and even biology to create machines the size of molecules. In this interdisciplinary domain, researchers design nanorobots, machines typically 1–1000 nanometers across, that can operate with extreme precision in environments where ordinary machines cannot.

For scale, nanorobots are comparable to or smaller than biological cells, meaning they can potentially swim through the bloodstream, crawl along DNA, or maneuver among nanoparticles. Because they exploit unique nanoscale physics and chemistry (such as quantum effects and surface forces), these tiny robots could revolutionize medicine, manufacturing, environmental monitoring, and more. 

At its core, nanorobotics aims to manipulate matter at the molecular level. The vision is that fleets of nanobots could navigate complex environments (inside the body or in the lab) and execute tasks with unprecedented accuracy. By combining tools from robotics, nanofabrication and bioengineering, scientists hope to build machines that can assemble, inspect, or repair structures atom by atom or molecule by molecule. In principle, this could enable breakthroughs from programmable drug carriers to bottom-up manufacturing of novel materials. [...]

As we already mentioned in the issue "Microbiota - You are not just you", one of the most surprising fronts in microbiota research is the discovery of the gut-brain axis: a communication highway between the gut microbiota and our nervous system. It sounds almost like science fiction:

How might gut bacteria influence our mood, stress or even behavior?

However, mounting evidence shows that they do, through a network of connections that link the gut and brain both physically and biochemically. Communication occurs via neural pathways (such as the vagus nerve), immune signals and microbial metabolites. Factors such as diet, stress or infections influence this bidirectional communication.

To achieve movement, scientists have created a variety of micromotors. Some teams use tiny helical coils that spin under rotating magnetic fields, mimicking bacterial flagella. Others use light-activated materials, pH-sensitive polymers or enzymatic reactions to move when triggered. These micromotors often exploit self-assembly or nano-patterning for fabrication (for instance, rolling up thin films or coating beads). Despite the diversity of approaches, a common goal is the same: convert some energy source (chemical, magnetic, acoustic, or even biological) into continuous thrust that can be controlled to direct the nanobot where it needs to go.

Beyond purely synthetic motors, biohybrid strategies incorporate living cells or biomolecules into nanorobots. The idea is to use nature’s nanomachines as components. For instance, bacteria like E. coli or Salmonella have evolved efficient flagella-driven swimming. Researchers have attached magnetic microstructures to these bacteria so that an external magnetic field can guide the organism’s built-in propulsion. In effect, the bacteria serve as an engine and sensor, carrying a tiny payload or device to a target. Similarly, microscale swimmers have been built using sperm cells as motors. Additionally, cell membrane-coating techniques provide nanorobots with enhanced biocompatibility, enabling them to evade immune responses and function effectively within living organisms. [...]

Imagine taping a tiny payload to a bacterium and letting physics take the wheel, that’s the level of creativity happening here.

Medical applications

The most immediate applications of nanorobotics are in medicine. In principle, nanobots could roam inside the body performing tasks at cellular resolution. For example, they might be injected into the bloodstream to deliver drugs directly to diseased cells, target cancer cells, or perform minimally invasive surgeries. 

By homing in on a target (say, a tumor) and releasing a drug only there, a nanobot could greatly increase efficacy while sparing healthy tissue. Targeted therapy like this would reduce doses and side effects, because much less drug is needed when it is delivered exactly where it is needed.

Beyond drug delivery, nanorobots could serve as tiny surgeons or diagnostics. They might clear blockages in capillaries, stitch or repair cells, or biopsy tissue too small to reach with traditional tools. Sensors on nanobots could detect chemical signals of disease early on.

Ultimately, nanorobotics represents more than just a miniaturization of machines. It is a redefinition of robotics itself, guided by principles of biology, quantum physics, and material science. As researchers continue to unlock the secrets of nanoscale dynamics and develop bioinspired and biointegrated designs, nanorobots could soon become indispensable tools for exploring and transforming the world at the smallest scales. [...]

🪄 Bonus Insight

Nanorobots in healthcare today are where CRISPR was in 2012: understood in theory, tested in labs, awaiting the breakthroughs that will unlock their billion-dollar potential.

Startup ecosystem

Nanobots Therapeutics

Company based in Spain

Founded in 2023

Nanobots Therapeutics is a pre-clinical stage biotech company dedicated to the development of innovative therapies using nanorobots capable of self-propelling in body fluids and crossing complex biological barriers. These nanovehicles enable the delivery of treatments directly to target tissue, including solid tumours. Our first therapeutic indication is bladder cancer.

Nanobots Therapeutics is a spin-off of the Institute for Bioengineering of Catalonia (IBEC) and the Catalan Institution for Research and Advanced Studies (ICREA). The company is developing a new nanobot-based drug delivery platform called Therapeutics in Motion (MotionTx). These nanobots are self-propelled nanoparticles capable of delivering drugs to target tissues, e.g. for the treatment of different solid tumours.

**Nanobots Therapeutics raised 125.6% of its €1,500,000 target in 2024 via Capital Cell.

Future Perspective: Bio-nanoproduction

Today, low Earth orbit is crowded with more than 100 million pieces of debris, everything from defunct satellites to screws drifting at 28,000 km/h. What began as a triumph of engineering quickly became a crisis of cleanup. […] And we didn’t see it coming fast enough.

Now, we’re standing at a similar threshold with nanorobotics. The promise of deploying molecular machines inside the human body is real, but so is the risk of accumulation, persistence, and loss of control.

What happens if we saturate the body with these tools, without a plan for their removal, degradation, or decay?

Here are the questions we should be asking today, not after the fact:

• Could nanorobots accumulate inside the body over time, like space debris?
  Yes. Especially if they're designed to persist, operate over long durations, or lack self-destruct protocols. In a chronic treatment scenario, long-term buildup could become an issue.
• Is there a risk that nanorobots left behind could cause inflammation or interfere with future diagnostics
  Potentially. Foreign particles, even if inactive, can trigger immune responses or mislead diagnostic imaging. We already see this with some nanoparticles used in imaging agents or drug delivery.
• What mechanisms exist (or are being researched) to retrieve or biodegrade nanorobots after use?
  Some research points to biodegradable nanomaterials (like DNA origami, hydrogel-based bots, or magnesium-zinc alloys), but controlled retrieval is still largely hypothetical. No clinical standard exists yet.
• Could this lead to a systemic pollution problem, not just individual risk, but environmental spillover?
  If nanorobots are excreted or flushed into water systems, it's plausible. This is where bio-nanopollution extends beyond the body into ecosystems, especially if bots are engineered for long-term stability.
• Are there lessons from space debris policies that we can apply here?
  Absolutely. Concepts like “end-of-life protocols,” “active removal,” and “international accountability” are directly translatable. But in biotech, regulation always lags innovation. That’s our window.

We’ve asked our questions and done our best to answer them, yes. But what truly excites me is the thought that, one day, my grandchildren might ask me:

Grandma, how did people get better before nanorobots?

And I’ll smile and tell them about the medicine of today. Maybe these words will read like a time capsule by then.

I’m just a traveler through time, from today to tomorrow, and tomorrow back to today.