Charlie Stross reckons that The Pirate Bay's idea of having file-sharing drones circling the skies of Sweden is a good idea going the wrong way and that they should look to the humble rodent for inspiration instead - Pirate LOSS? An alternative ....

I'm going to assume that you know who and what The Pirate Bay are.

The Pirate Bay just announced a nifty but somewhat questionable application for the Raspberry Pi low-cost Linux computer:

With the development of GPS controlled drones, far-reaching cheap radio equipment and tiny new computers like the Raspberry Pi, we're going to experiment with sending out some small drones that will float some kilometers up in the air. This way our machines will have to be shut down with aeroplanes in order to shut down the system. A real act of war.

We're just starting so we haven't figured everything out yet. But we can't limit ourselves to hosting things just on land anymore. These Low Orbit Server Stations (LOSS) are just the first attempt. With modern radio transmitters we can get over 100Mbps per node up to 50km away. For the proxy system we're building, that's more than enough.

I applaud their ingenuity, but I think this can be improved upon.

The LOSS concept has several drawbacks. First among these is power consumption and payload weight constraints. The Raspberry Pi is a low power device, but still draws juice via micro-USB, at up to five watts. On top of which, TPB propose to broadcast a wifi signal from their LOSS drones. To blanket an area of a square kilometre with a strong enough signal to sustain a high data rate (they say around 100mbps) is going to take both a decent antenna and a fair amount of electricity. All of which is going to drive up the weight, complexity, and cost of the LOSS.

LOSS needs to either be self-sustaining (which implies solar propulsion, along the lines of ELHASPA or NASA's Pathfinder aircraft) or it's going to have to land regularly to take on fuel. (I am ruling out nuclear propulsion because I assume The Pirate Bay do not have access to a supply of fissionable materials. Otherwise, it's Game Over for the MPAA.) This means that a cat-and-mouse game can be easily won by the authorities; there's no need to deploy air-to-air missiles over built-up areas when you can just have the Police keep an eye out for pirates refuelling their drones after midnight.

The sad truth is, quadrotors and small UAVs have lamentably poor airborn endurance, with flight durations measured in double or triple digit seconds rather than minutes, let alone hours. And baloon-type UAVs have the slight problem of being at the mercy of the winds, or requiring an anchor cable (which again makes them trivially easy for the Police to take down).

Rather than looking up at the stars, I believe the Pirate Bay should be looking down at the sewers. Their robot minions would be better modelled on the humble sewer rat than on the soaring seagull.

In the city, you are never more than three metres away from a rat. They're spectacularly successful. We've built them a wonderful habitat replete with high-speed autoroutes — storm drains and sewers — and convenience stores to snack from in the shape of dumpsters and trash. And ground level is where most of us wifi users happen to be, most of the time.

Small ground-traversing robots would not be subject to the same weight penalties as airborn drones. The wifi range would be shorter, but their power consumption would be lower and they'd be far more concealable — it's quite easy to imagine a ratbot that is, literally, no larger than a real rat.

Powering ratbot would be easier, too. In suitably hospitable environments Pirate Bay operatives could lay down inconspicuous inductive charging mats plumbed into power outlets. Alternatively, SlugBot shows the way towards a truly autonomous ground-dwelling robot—one that hunts for biological prey, digests it, and uses an on-board microbial fuel cell to provide electricity. In an urban environment ratbot need not hunt and kill moluscs to survive; instead, it could subsist on pizza rinds and the dregs from Mountain Dew cans, which would doubtless be easier to stalk and kill. Indeed, the rich pickings behind any fast food outlet would attract ratbots to the very same location where bittorrent users might congregate to furtively use their provided bandwidth.

Finally, if ratbot detects the presence of Police ferretbots in the neighbourhood, it can make its escape in a number of ways — climbing a nearby wall, clinging to the underside of an automobile (an especially efficient way of spreading the mesh network to other cities), diving into a storm drain (better hope the waterproof seals hold!), or asking a friendly Pirate Bay user for a ride.

Science Daily has an update on the world of microbial fuel cell research - Nanotech Coatings Produce 20 Times More Electricity from Sewage.

Engineers at Oregon State University have made a significant advance toward producing electricity from sewage, by the use of new coatings on the anodes of microbial electrochemical cells that increased the electricity production about 20 times.

The findings, just published online in Biosensors and Bioelectronics, a professional journal, bring the researchers one step closer to technology that could clean biowaste at the same time it produces useful levels of electricity -- a promising new innovation in wastewater treatment and renewable energy.

Engineers found that by coating graphite anodes with a nanoparticle layer of gold, the production of electricity increased 20 times. Coatings with palladium produced an increase, but not nearly as much. And the researchers believe nanoparticle coatings of iron -- which would be a lot cheaper than gold -- could produce electricity increases similar to that of gold, for at least some types of bacteria.

"This is an important step toward our goal," said Frank Chaplen, an associate professor of biological and ecological engineering. "We still need some improvements in design of the cathode chamber, and a better understanding of the interaction between different microbial species. But the new approach is clearly producing more electricity."

In this technology, bacteria from biowaste such as sewage are placed in an anode chamber, where they form a biofilm, consume nutrients and grow, in the process releasing electrons. In this context, the sewage is literally the fuel for electricity production.

In related technology, a similar approach may be able to produce hydrogen gas instead of electricity, with the potential to be used in hydrogen fuel cells that may power the automobiles of the future. In either case, the treatment of wastewater could be changed from an energy-consuming technology into one that produces usable energy.

Cleantech.com has a post on research into using microbial fuel cells to desalinate water - Penn State discovers new electricity-generating desal process.

Researchers from Pennsylvania State University and China have discovered a new desalination process that has a triple cleantech benefit. The process cleans wastewater, generates electricity and can remove 90 percent of salt from brackish water or seawater.

The researchers are hoping to prove that desalination is possible without the large amounts of energy required by reverse osmosis or electrodialysis. The high energy and infrastructure cost of reverse osmosis has inhibited the adoption of desalination in the United States because municipalities have been able to easily and cheaply pump water in from surrounding rivers and regions (see Largest desalination plant in Western world gets go-ahead).

"It currently takes a lot of electricity to desalinate water,” said Penn State Professor Bruce Logan, in a news release. “Using the microbial desalination cells, we could actually desalinate water and produce electricity, while removing organic material from wastewater.”

The team modified a microbial fuel cell, which uses naturally-occurring bacteria to convert wastewater into clean water and electricity, to desalinate salty water.

Typical microbial fuel cells have two chambers, one containing wastewater or other nutrients and the other containing water, according to the news release. Bacteria in wastewater consume the organic material, producing electricity.

The researchers altered the cell, adding a third chamber between the two existing chambers and placing certain ion-specific membranes—membranes that allow positive or negative ions through, but not both—between the central chamber and the positive and negative electrodes.

The study intended to show that bacteria could produce sufficient current to do this, but it ended up taking 200 milliliters of an artificial wastewater to desalinate 3 milliliters of salty water. The process, while not yet optimized, serves as proof of concept, according to Logan.

Technology Review has a look at efforts to introduce microbial fuel cells in Africa, on the basis they are easier to set up than small solar panels (probably the main source of power in off the grid Africa) - Microbes for Off-the-Grid Electricity.

Microbial fuel cells, which use electrodes in dirt to power a small motor, have long been more or less a laboratory curiosity. Because they generate such a small amount of power, developing them to charge devices would not be practical in places where electricity is readily available. However, Lebônê Solutions, a startup based in Cambridge, MA, aims to use microbial fuel cells to provide power to Africans who are off the grid. In some parts of Africa, a small amount of energy is enough for a few hours of lamp light in the evening, or for powering the ubiquitous cell phones--something that some residents will walk five hours to a generator to do, says Aviva Presser, a cofounder of Lebônê. The company is made up largely of Harvard University alumni and current Harvard students originally from African countries.

With funding from the Harvard Institute for Global Health, the team has recently completed a pilot study in Tanzania, where members brought six basic microbial fuel cells and taught residents how to use them. The team organized village meetings where team member and Tanzanian native Stephen Lwendo explained how to make the fuel cells.

The team found residents receptive to the idea of easy-to-grow power and keen to use the fuel cells to charge cell phones, run radios, and provide more light. "In Africa, people want to power [small] DC devices," as opposed to large AC devices like a refrigerator, says Lebônê cofounder Hugo Van Vuuren, a Harvard graduate and a South African native. The team hopes to develop the technology to make it competitive with other renewable energies in countries across Africa. Microbial fuel cells could have a distinct advantage because they are initially cheaper to build than a windmill and easier to set up than solar panels. What's more, they could last up to 10 years, says Lebônê cofounder David Sengeh.

Instead of using hydrogen as a fuel, as do conventional fuel cells, microbial fuel cells use naturally occurring microbes to generate power. Bacteria live in the anode, where they eat glucose, sewage, or other waste water, and turn that into electrons and protons. The bacteria transfer electrons to the circuit, which provides small amounts of power.