Jimmy the Geek

Teensy-weensy transistors...

QuIET: Quantum Interference Effect Transistors!

University of Arizona physicists have discovered how to turn single molecules into working transistors. It's a breakthrough needed to make the next-generation of remarkably tiny, powerful computers that nanotechnologists dream of.

They have applied for a patent on their device, called Quantum Interference Effect Transistor, nicknamed "QuIET." The American Chemical Society publication, "Nano Letters," has published the researchers' article about it online at Nano Letters. The research is planned as the cover feature in the print edition in November. <read more>

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This is cool some stuff.  I've recently become obsessed with nano-technology and it seems like there is something new every day. 

The Pentium 4 CPU has somewhere around 55,000,000 transistors.  Each of those transistors can be as small as 65 nanometers.  If you've been around computers much, you know about the heat the CPU generates.  That heat translates to lost energy.  25 nanometers is considered the minimum size limit for current technology transistors because of the tremendous energy required. 

"Even if it were possible to build an ultra-advanced laptop computer with molecule-sized transistors using current transistor technology, it would take a city's worth of electricity to run the laptop, and the thing would get so hot it would probably vaporize."

The QuIET technology promises to reduce the size of a single transistor to ONE nanometer.  A billionth of a meter.  And the CPU mentioned before would run at room temperature.

This is exciting stuff!

Bio-batteries...

This just in...

A research team in Sydney has created molecules that mimic those in plants which harvest light and power life on Earth.
“A leaf is an amazingly cheap and efficient solar cell,” says Dr Deanna D’Alessandro, a postdoctoral researcher in the Molecular Electronics Group at the University of Sydney. “The best leaves can harvest 30 to 40 percent of the light falling on them. The best solar cells we can build are between 15 and 20 percent efficient, and expensive to make.”

“We’ve recreated some of the key systems that plants use in photosynthesis,” says Deanna.  <read the article>

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Kudos to the Aussies for doing this kind of research.  There is so much untapped solar energy out there and it's not going away.  Unlike our precious natural resources, the sun is pretty much an infinite power source... at least for the next few million years.  We need to take advantage of it.

The beauty of this research is that the result is more efficient than the traditional solar cell systems.   30% to 40% efficiency doubles what is currently possible.   Hopefully less expensive too.

A few days ago, I was sitting on the couch with the sun beating down through the window.   It felt good for a while, but soon it became too hot.  As I started pulling the shade down a bit, I had one of those 'Wow!' moments when it occured to me that the Sun, at 93,000,000 miles away, could produce so much heat.  THAT'S a lot of energy!

Pluto not a planet?

Pluto Loses Planet Status

By Lisa Pickoff-White
August 24 - The International Astronomical Union has stripped Pluto of its planetary status. Pluto was discovered in 1930 by American astronomer Clyde Tombaugh of Arizona's Lowell Observatory and classified as a planet. In 2003, Pluto’s standing was called into question when astronomers found a larger object, UB313, in the Kuiper Belt, an area beyond Neptune filled with large icy objects and believed to be the source of many comets.

Approximately 2,500 experts at the IAU’s general assembly voted to change Pluto’s status, rejecting a proposal that would have retained Pluto as a planet and brought three other objects into the planetary club. Pluto is considerably smaller and more distant than the other planets in our solar system. Two-thirds the size of Earth's moon, Pluto's classification as a planet came under scrutiny when many objects of similar size and distance were discovered in the Kuiper Belt in the 1990s.

The Space Studies Board provides an independent, authoritative forum for all aspects of space science and applications, and it serves as the focal point within the National Academies for activities on space research.  -link-

SMT Hot Air Reflow Soldering Gun

Got hot air?

I just fabricated this hot-air soldering gun for about $25.  That's a far cry from the $400-$500 rework stations that we all drool over.  But it works great!   I have to admit it wasn't my idea... I got the inspiration from this website.

The iron is a $10.49 Radio Shack 45W Desoldering Iron.  I removed the bulb and replaced it with a hose attached to a fish tank air pump.  You don't need a lot of air flow so I stuffed the chamber that the tip screws into with a fine steel wool to slow down the air flow a bit and to allow more surface area to heat the air as it flows by. 

Preliminary testing (using a thermocouple) gave me a temperature of nearly 400 degrees F, which is ample to melt SMT solder paste which has a melting point of around 360 degrees F.   I'm still waiting for a tube of solder paste, but I can easily melt conventional solder with the device.

Hot air is one method of soldering tiny surface-mount components to a circuit board.  The components are so small that it's difficult to use a conventional soldering iron on them.   The photo to the left is a circuit board from a USB flash drive to give an idea how small the SMT components are.  Notice the partial view of the USB plug on the right side of the picture.  Them're some itty-bitty components!