While I do not know precisely how this distiller works, in general a distiller would boil the water, collect the steam in baffles and let it condense into water and flow out of the machine. 

Dean Kamen claims that this machine cleans all forms of dirty water.  I am not sure how this is possible without membranes or filters.  Any volatiles in the water with a boiling point less than or equal to that off water will boil off and possibly be collected in the baffles.

Regardless, it is an impressive machine as it will save thousands of lives.

Kevin Knuth
Albany NY 

I have thought about linear designs of this sort, but a rotary design is much more practical. Very nice.

An elegant worm-gear multiplexer submitted to nxtasy.org by Guy Ziv provides another solution in the event that your two outputs do not need to change direction.

Kevin Knuth
Albany NY

I described the rocker-bogie suspension system in a previous post.  The idea originated with the bogie, which is a set of six wheels on a train designed in such a way to keep all the wheels on a curved track.  The innovation here is to add rockers allowing the wheels to move up and down independently.  This enables the rover to handle extremely rough terrain, and as I demonstrate, climb barriers higher than the wheels themselves.  A more detailed description can be found on BrickVista Tech-Notes.

The first demo was filmed in my brother’s backyard in Wisconsin where he had just put in a fence.  The terrain is relatively rough with bumps and dips with sizes on the order of the diameter of the rover’s wheels.

The second demo was filmed in my office in the Physics Department at the University at Albany.  Here the rover climbs a pile of some of my favorite books.  Several of the book heights are on the order of the diameter of the wheels themselves.  Watch how the rockers allow the wheels to climb independently.

The third demo was filmed in the access road just outside the Physics Department.  A small parking barrier, approximately the height of a curb, is the obstacle to be overcome.  The rover is able to climb the barrier, and the rocker-bogie suspension allows its wheels to hug the barrier as it rolls over.  The rover then heads off towards a small tree… perhaps in search of life. 

We improved on the design by increasing the torque on the tires (decreasing the speed) and by replacing the front drive shafts with a gear system.  Long LEGO axles tend to take a good deal of torsion and store this energy like a spring.  This leads to oscillatory motions in the wheels.  In addition, the coupling was too weak to enable our rover to climb the desired obstacles, and our gear system overcomes this.  Another way we found to overcome the torsion of long drive shafts is to construct a shaft out of small axles joined by axle connectors.

There are more improvements to be made.  One design flaw is that the front wheels are too powerful and sometimes lift the entire front end of the rover without allowing the rockers to rotate.  This is because the back wheels are also progressing a given rate of speed and for the rockers to rotate, these wheels would have to slow down.  A properly-placed differential should solve this problem.

In the meantime, this basic rover design is sufficiently robust for outdoor exploration.

Below are several books of potential interest.

Kevin Knuth
Albany NY

Google has a relatively new search engine that searches for patents.
This is extremely useful for that entrepreneur involved in patenting his or her ideas.

http://www.google.com/patents

Kevin Knuth
Albany NY

To make a useful scanner, I would prefer to use one motor rather than two.  This will require some complex gearing, but it is straight-forward.  The part that had me a bit puzzled was the fact that I want the scanner to make one horizontal sweep while maintaining a constant vertical position.  Once the horizontal sweep is finished, I need it to nudge the vertical orientation of the mirror just a bit, and then perform another horizontal sweep and so on.  How to do this with a single motor was not clear.  Until I came across a set of fabulous mechanisms by Leo Dorst of the Intelligent Systems Laboratory Amsterdam at the University of Amsterdam in The Netherlands.

Leo Dorst created a Lego version of the Geneva Mechanism, which moves film through a projector by holding it still while intermittently feeding it through the mechanism.  His sketch is above, but better images and instructions exist on his website.  He has a wide variety of Lego Mechanisms, that I am sure I will find useful in the near future.

In the meantime, his design (below) of a six degree-of-freedom robotic arm is fantastic!!!

I have found the books below to be very good.

Enjoy,
Kevin Knuth
Albany NY