A major issue is the failure mode. Hard failures will render the device completely inoperable whereas soft failures can cause the device to continue to function but make mistakes. In medical applications, you don’t want implanted nano devices making mistakes!

Additionally, the environment in which they are used must be very stringently controlled to reduce failures. Just normal background radiation found at sea-level has been calculated to cause progressive failures of the devices at a rate of 10E-4, which is an unacceptably high rate. Getting an MRI while the devices are implanted could fry a significant percentage of the devices. Simply talking on your cell phone could generate enough RF (radio frequency) energy to destroy a percentage of the implants in proximity of the cell phone’s antenna.

These are all problems that can be addressed theoretically but current design technology and redundancy concepts that may work are still decades away from proving them as viable.

For now, the real exciting news on the medical front is in non-intelligent nanotechnology. Nano carbon fibers are being developed that will attach only to specific cancer cell wall proteins. When radiated with RF energy, they will heat up and kill the cancer while leaving normal cells (which they can’t bind to) completely unharmed. Also nanotechnology drug delivery concepts are being developed that will deliver drugs to very specific cells and locations in the body. This will decrease the dosing levels significantly, greatly decrease the chance of contraindications, and provide highly targeted drug therapies never before possible. A number of non-intelligent nanotechnology concepts are in clinical trials now and may soon be at a pharmacist near you.

Within a decade, curing certain forms of cancer may be as simple as getting an injection then stepping into an RF chamber for 30 minutes – barely enough time to read a few articles in your favorite magazine – and you’re cured. Now that’s exciting!