Micronautics? Maybe you have heard this word before, but as I typed it in my word processor the spell-checker highlighted it right away. So it is not in the dictionary yet. It will be there one day. How soon this will happen? I guess it depends on our techno progress, but I am sure: we need it.
The subject of micronautics was explored in sci-fi for a while. I remember one short story about a guy who carried a friendly nano-robot inside his body. The robot was scouting his blood vessels and cleaning them from all possible contaminants. Sometimes it entertained the fellow with insightful talks, until one day the host almost choked on a clam and good robot pushed the thing out of his airways. Sadly, the robot was too small, so it was lost in a spit.
"Being lost in a spit" " one has to be pretty small for such misfortune. Indeed, nano-vehicle must be approximately million times smaller in linear dimension comparing to a regular (large) vehicle. In other words, take the sizes of an eighteen-wheeler in meters, change meters to micrometers, and you have a set of comparable sizes for a nano-vehicle. What will be the best application area for such miniscule machine? The inner microspace of a human body, of course! Apparently, if it can navigate inside our blood vessels, then the benefits which we can get from such machine are beyond imagination. When implemented, micronautics, i.e. autonomous navigation in microspace, will change our medicine to ever unthinkable heights. Imagine such vehicle moving along an artery and cleaning it from atherosclerotic deposits or infectious bacteria or defected blood cells. Hundreds, maybe thousands of potential deceases can be subdued and maybe even eradicated by such cleaning service.
You just have to "swallow your doctor", as Richard Feynman, great American physicist, once put it. Feynman was using the original idea of his graduate student, Albert Hibbs (see R. Feynman, Theres Plenty of Room on the Bottom, 1959). Of course, there is a plenty of room: not just blood-janitors, one day these things will be able to communicate with our brains and in this case I just wonder if a freedom of free will is granted us by constitution: we may need another amendment. Just think about the possibilities: "swallow your math teacher", "swallow your tax accountant", "swallow your parole officer" there will be no limits. Fortunately, we would hardly deal with this issue in the first half of this century: there is a plenty of technical problems to be solved first.
It took a century to develop such sophisticated aeronautics, as one that we have today. How much time do we have before the frontier of micronautics could be taken over as well as airspace? Perhaps, considering acceleration of technological progress, we will get to that point within a shorter period of time. One of the "simplest" tasks will be design of an engine for nano-robots. The problem is that one cannot just scale down any existing mechanical engine, because comparing to our macroscopic world, material properties and dominating physical processes at micron scales will be different. An engine of nano-vehicle must have very few moving parts, comparing to our vehicles. How one can make such a thing?
Beamed-energy propulsion (BEP) is an answer. Most of currently developing applications of BEP are designed for space. BEP principle is this: energy is beamed to the vehicle from a separate (often remote) source. The vehicle collects the beam and converts its energy into mechanical motion. In space applications the most typical scenario would be powerful laser, which remotely drives a spacecraft with collecting optics (mirrors) and solid propellant. Mirrors will focus collected light on propellant, which will be explosively evaporated, acting like a burning rocket fuel only with much higher energy density. This process is called ablative laser propulsion: the engine of a spacecraft has no moving parts, but it produces energetic exhaust, and spacecraft is flying using rocket principle. It will work well in space, but what about a micro-space of a human body? Who needs a rocket inside blood vessels?
There will be no rockets, at nano-scales we can use other, less violent ways of propulsion. Aside from blood cells, which occupy 55% of blood volume, the medium for motion in blood is a liquid, 90% of which is water. The fastest means of motion in our blood employed by many bacteria is so-called flagellum, a helical appendage, which acts as a propeller. A similar element can be used in micro-robots. Magnetic field can penetrate human body without substantial losses. The simplest beam-powered nano-engine will be composed of a nano-circuit, in form of a solenoid or loop, which can rotate or wiggle under external magnetic field. With flagellum attached to the circuit, nano-robot can move in direction set by orientation of the field.
In 1959 Richard Feynman predicted that nano-doctors will be moving by means of electric motors, driven by external EM fields. Today, 50 years later, we have a choice of several approaches to the problem. For example, in 2002 at First International Symposium on Beamed Energy Propulsion (ISBEP) professors from Tokyo Tech University, Shiho and Yabe, have presented a possibility to drive nano-robots with x-ray lasers. The next, Sixth ISBEP will be held in November 2009 in Scottsdale, Arizona. As expected, the discussion on micronautics will be continued there. - 15437
The subject of micronautics was explored in sci-fi for a while. I remember one short story about a guy who carried a friendly nano-robot inside his body. The robot was scouting his blood vessels and cleaning them from all possible contaminants. Sometimes it entertained the fellow with insightful talks, until one day the host almost choked on a clam and good robot pushed the thing out of his airways. Sadly, the robot was too small, so it was lost in a spit.
"Being lost in a spit" " one has to be pretty small for such misfortune. Indeed, nano-vehicle must be approximately million times smaller in linear dimension comparing to a regular (large) vehicle. In other words, take the sizes of an eighteen-wheeler in meters, change meters to micrometers, and you have a set of comparable sizes for a nano-vehicle. What will be the best application area for such miniscule machine? The inner microspace of a human body, of course! Apparently, if it can navigate inside our blood vessels, then the benefits which we can get from such machine are beyond imagination. When implemented, micronautics, i.e. autonomous navigation in microspace, will change our medicine to ever unthinkable heights. Imagine such vehicle moving along an artery and cleaning it from atherosclerotic deposits or infectious bacteria or defected blood cells. Hundreds, maybe thousands of potential deceases can be subdued and maybe even eradicated by such cleaning service.
You just have to "swallow your doctor", as Richard Feynman, great American physicist, once put it. Feynman was using the original idea of his graduate student, Albert Hibbs (see R. Feynman, Theres Plenty of Room on the Bottom, 1959). Of course, there is a plenty of room: not just blood-janitors, one day these things will be able to communicate with our brains and in this case I just wonder if a freedom of free will is granted us by constitution: we may need another amendment. Just think about the possibilities: "swallow your math teacher", "swallow your tax accountant", "swallow your parole officer" there will be no limits. Fortunately, we would hardly deal with this issue in the first half of this century: there is a plenty of technical problems to be solved first.
It took a century to develop such sophisticated aeronautics, as one that we have today. How much time do we have before the frontier of micronautics could be taken over as well as airspace? Perhaps, considering acceleration of technological progress, we will get to that point within a shorter period of time. One of the "simplest" tasks will be design of an engine for nano-robots. The problem is that one cannot just scale down any existing mechanical engine, because comparing to our macroscopic world, material properties and dominating physical processes at micron scales will be different. An engine of nano-vehicle must have very few moving parts, comparing to our vehicles. How one can make such a thing?
Beamed-energy propulsion (BEP) is an answer. Most of currently developing applications of BEP are designed for space. BEP principle is this: energy is beamed to the vehicle from a separate (often remote) source. The vehicle collects the beam and converts its energy into mechanical motion. In space applications the most typical scenario would be powerful laser, which remotely drives a spacecraft with collecting optics (mirrors) and solid propellant. Mirrors will focus collected light on propellant, which will be explosively evaporated, acting like a burning rocket fuel only with much higher energy density. This process is called ablative laser propulsion: the engine of a spacecraft has no moving parts, but it produces energetic exhaust, and spacecraft is flying using rocket principle. It will work well in space, but what about a micro-space of a human body? Who needs a rocket inside blood vessels?
There will be no rockets, at nano-scales we can use other, less violent ways of propulsion. Aside from blood cells, which occupy 55% of blood volume, the medium for motion in blood is a liquid, 90% of which is water. The fastest means of motion in our blood employed by many bacteria is so-called flagellum, a helical appendage, which acts as a propeller. A similar element can be used in micro-robots. Magnetic field can penetrate human body without substantial losses. The simplest beam-powered nano-engine will be composed of a nano-circuit, in form of a solenoid or loop, which can rotate or wiggle under external magnetic field. With flagellum attached to the circuit, nano-robot can move in direction set by orientation of the field.
In 1959 Richard Feynman predicted that nano-doctors will be moving by means of electric motors, driven by external EM fields. Today, 50 years later, we have a choice of several approaches to the problem. For example, in 2002 at First International Symposium on Beamed Energy Propulsion (ISBEP) professors from Tokyo Tech University, Shiho and Yabe, have presented a possibility to drive nano-robots with x-ray lasers. The next, Sixth ISBEP will be held in November 2009 in Scottsdale, Arizona. As expected, the discussion on micronautics will be continued there. - 15437
About the Author:
Andrew Pakhomov is founder and president of American Institute of Beamed Energy Propulsion, a nonprofit scientific organization serving to development and popularization of this space technology of the future AIBEP He is also associate professor of physics at University of Alabama in Huntsville. To read more about emerging field of beamed-energy propulsion and its applications, please visit official site of AIBEP.
