Defense and Aerospace

SIlver Cell construction (via The Autralian NAtional University)

Soldiers carry a lot of weight. With radios, night-vision devices, flashlights, communication systems, ammunition, and other basic supplies the weight approaches the point of hurting the person carrying it all. In fact, major-general of the Australian army said, "It's not good for a soldier's back to be carrying that much weight."

One area that can benefit from advancing technology has been the size of the electronics and the power systems. In the distant past, communications were powered by heavy lead-acid batteries. Later came lighter weight battery packs that have been getting smaller and more energy dense every year. The progress does not stop here. The Australian army is testing the possible use of lightweight solar panels, eliminating the need for any large battery pack.

The new solar cells are a bit different than standard silicon based panels. Called "Silver Cells," the panel arranges the photovoltaic elements in thinly sliced pieces, vertically, in a silicon frame. The cells use 90% less silicon than other mono crystalline cells of equivalent output. In other words, the costs are lower.

The elements are 50 to 100mm long, 1 - 2mm wide, and 45micrometers thick. Both sides of the element can absorb light. Due to the bifacial response of the Silver cell, the optimal angles are increased. And the cells work well on curved surfaces. Open circuit voltage of the cell is in the 600 - 700mV range. Connected in series or parallel, for whatever voltage the application needs, the cells are capable of 140 Watts per square meter.

The plan is to cover soldier's helmets, tents, and clothing. Testing will be conducted over a few years before acceptance for true field use. What they will soon discover is that the reflective nature of solar panels will not be good for concealing soldiers or objects. Much like flashing the sun off a mirror at your enemies. I would imagine a whole group of soldiers would look like they are sparkling. Not the most intimidating look out there.

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Boeing 747-8 via Boeing

Seeing a trend in aircraft biofuel usage?

Boeing has recently demonstrated the use of a camelina-based biofuel in one of their unmodified 747-8 Freighter airplanes. The camelina biofuel is a mixture of 85% kerosene fuel, called Jet-A, and 15% processed oils from the camelina organic plant. Camelina plant seeds have an oil content in the range of 37-41%, and it is rich in omega-3 fatty acids. When the oils are heated in the excess of 450°C in the absence of air (oxygen), it causes the molecules to break forming chemical compounds similar to those found in petrodiesel. This process is called pyrolysis, and sometimes thermal cracking or cracking.

Camelina plant, via Camelina Wiki

The camelina plant was grown in Montana, USA, and Honeywell's UOP processed the plant into the biofuel used in the demonstration. The 747-8 cargo plane made its 4,989 mile transatlantic flight without a single issue. The fuel comes from a 5 year program that Boeing and several other aircraft companies started as a way to develop sustainable biofuels.

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A team from the University of Southampton has used 3D printing techniques to build a working UAV from the ground up in just under a week. The team, led by Andy Keane and Jim Scanlan, demonstrated their effort at an air strip just a little down the road from Stonehenge. The 1.5 meter wing span, ultra-low-drag, aircraft successfully flew showing it is possible to build for each individual application.

At 100 micrometers (4 thousands) at a time, a laser traces out the 2D cross section of the design. The laser can "print" with many different types of materials, from polyamide plastic to stainless steel or titanium powder. When forming parts with the metallic powder, the team stated that it is as strong as if the parts were machined from raw/bare metal. To create a stronger formed part, an electron laser sintering is used, instead of the conventional laser, to melt the powder completely.

Of course, the electronics in the craft are not printed. At least not yet. http://www.element14.com/community/community/doittogetherblog/blog/2011/07/14/grow-electronics-by-the-molecule

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