When we're sick we expect to take some medicine or get therapy or at worst, surgery, but how about getting an injection of medical microbots instead? Cool. That almost sounds like getting my own private micro Transformers to battle my diseases. You know, it's kind of like that.

Medical microbots are microscopic automated machines that are so small they can travel anywhere in the body and can perform specific tasks. For example, they might clean out an artery, obtain a biopsy, or treat a tumor. Being about the size of a human cell, these robots would do much less damage to tissues than conventional approaches such as surgery or insertion of catheters.

The goal is to make them even smaller and perform tissue engineering and regenerative medicine where damaged tissues or organs could be repaired or rebuilt completely. Another goal is to develop microbots that deliver therapeutic payloads such as drugs or imaging agents to specific spots in the body. In live small animals, microbots propelled by hydrogen microbubbles treated bacterial infections of the stomach by delivering drugs directly to the stomach wall where the bacteria were living.

The biggest challenge is locomotion and control. Microbots have to travel not only through fluids like blood, but also through air pockets like those in the stomach, intestine or lungs. So these microbots have to be like all-terrain vehicles.

If you get the robots to the location, you still have to activate them to do their job. Many methods are being tried including using sound, light and magnets. Research labs around the world are working on making them much more capable.