Teeny, Tiny Tools

red blood cells
Photo courtesy Garrigan.net
Nanorobot tools will have to
be small enough to manipulate
cells like these red blood cells.
Current microrobots are only a few millimeters long and about a millimeter in diameter. Compared to the nanoscale, that's enormous -- a nanometer is only one-billionth of a meter, while a millimeter is one-thousandth of a meter. Future nanorobots will be so small, you'll only be able to see them with the help of a microscope. Nanorobot tools will need to be even smaller. Here are a few of the items you might find in a nanorobot's toolkit:

  • Medicine cavity -- a hollow section inside the nanorobot might hold small doses of medicine or chemicals. The robot could release medication directly to the site of injury or infection. Nanorobots could also carry the chemicals used in chemotherapy to treat cancer directly at the site. Although the amount of medication is relatively miniscule, applying it directly to the cancerous tissue may be more effective than traditional chemotherapy, which relies on the body's circulatory system to carry the chemicals throughout the patient's body.
  • Probes, knives and chisels -- to remove blockages and plaque, a nanorobot will need something to grab and break down material. They might also need a device to crush clots into very small pieces. If a partial clot breaks free and enters the bloodstream, it may cause more problems further down the circulatory system.
  • Microwave emitters and ultrasonic signal generators -- to destroy cancerous cells, doctors need methods that will kill a cell without rupturing it. A ruptured cancer cell might release chemicals that could cause the cancer to spread further. By using fine-tuned microwaves or ultrasonic signals, a nanorobot could break the chemical bonds in the cancerous cell, killing it without breaking the cell wall. Alternatively, the robot could emit microwaves or ultrasonic signals in order to heat the cancerous cell enough to destroy it.
  • Electrodes -- two electrodes protruding from the nanorobot could kill cancer cells by generating an electric current, heating the cell up until it dies.
  • Lasers -- tiny, powerful lasers could burn away harmful material like arterial plaque, cancerous cells or blood clots. The lasers would literally vaporize the tissue.

The two biggest challenges and concerns scientists have regarding these small tools are making them effective and making them safe. For instance, creating a small laser powerful enough to vaporize cancerous cells is a big challenge, but designing it so that the nanorobot doesn't harm surrounding healthy tissue makes the task even more difficult. While many scientific teams have developed nanorobots small enough to enter the bloodstream, that's only the first step to making nanorobots a real medical application.

In the next section, we'll learn about where nanorobot technology is today and where it might be in the future.