Tuesday Tech Links

Time for another round of links and discussions of Science and Technology! (cue dramatic John Williams music).

What if the very substance of your house could clean your air and water and produce electricity for you to use?  That is the idea behind Smart Bricks. This kind of Bio-Tech is not my forte, but I understand the basics of Microbiological Fuel Cells (MFC) – certain biological processes produce electricity (electrolytes, actually) as a byproduct, and you can tap that zap. If those biological processes can also produce other useful byproducts, so much the better! In this case, the MFC can be encased in a structural ‘brick’ that is then used in the construction of a building. Waste systems are then fed through the ‘bricks’ and the micro life in the MFC eats the waste, generates voltage, and passes on clean(er) end product. No idea exactly what form this would take, or how the ‘bricks’ are maintained, etc. but not a bad idea. The idea, however, strikes me as something that would be eagerly adopted by people living in rural areas or off grid, but will likely be first pushed into commercial buildings in order to better hammer out bugs and pay for initial costs (if such ‘bricks’ could lower waste and energy costs, they’d be attractive to commercial buildings).

Reverse osmosis is still the king of desalination and other water purification tasks, but it is an expensive process. Evaporation and condensation comes in second, but it too is very energy intensive. So of course there is a drive to find less expensive, low power ways to make water drinkable, especially when it comes to making drinking water in the poorest places.  Lately, the focus has been on nanomaterials doing the work. One idea is using a graphene sheet (a form of carbon) to replicate the evap-condense cycle. The sheet has multiple layers and is laid on top of a water source. The bottom layers draw up water, and the graphene layer warms up from the sun, causing the water to evaporate, filter up through, and condense on the upper surface of the sheet, where it can be captured. Another uses a molybdenum nanosheet with nanopores that pull water molecules through while leaving salt and other larger molecules behind. Not as simple as just laying a blanket on the water, but still something that can work with very little power (a touch of positive pressure is all that is needed).

Speaking of membranes, here’s one that uses the salt ions present in salt water to generate electricity.  As the salt water molecules flow through the membrane, the salt ions impart a voltage to the membrane, that is captured. That is all pretty neat on it’s face, but what blew me away was the projected performance, that one square meter of the stuff could produce one megawatt of power. Drop an array of these is any estuary, and you’ll power a small city.

Still kinda related to membranes, Lockheed has an airship they are marketing. It’s a sight to behold, lifting body and ducted fans and all that, but one of the less heralded features is the maintenance staff, and crew of tiny SPIDER robots that skim the bag surface to find and repair holes. One half of the SPIDER is on the exterior surface with a light, and the other is on the interior with a photodetector, and they are magnetically bonded. Should it find a hole, it can effect a repair, take a photo of the work, and let a central computer know all about it. Can anyone say “DRD”?

Finally, stepping away from membranes and taking a hard left toward self defense. Remember this post, where I suggested that one way we could start working to reduce violence with firearms is to offer up effective less than lethal options to displace handguns? The other day, I ran across this, which is, quite honestly, something I’ve been thinking about. This is, effectively, a paintball gun, but instead of paint, it fires balls filled with pepper spray/powder. Pepper rounds already exist for firearms, but the fragile nature of the pellet means the rounds don’t have much gun powder in the cartridge, and won’t work the action on a semi-auto (they work well enough in shotguns and revolvers), and for most handguns, the amount of chemical irritant is many times too small to be effective, plus, you still have a gun that can be quickly loaded with deadly ammo. The Salt system is air powered and would require either excellent marksmanship or dumb luck in order to be lethal. Additionally, the rounds are large enough to contain enough irritant to probably be effective, and getting hit with a ball moving at 320 ft/sec is gonna hurt like hell if you aren’t well padded. They also claim that the irritant is what the military uses (suggesting it’s strong). I know one of the criticisms of chemical irritants is that they are often too weak, and a person can build up a resistance to the irritant with enough exposure (think iocane powder), but really, how many people who are not in the military are making the effort to learn how to endure a faceful of pepper spray or mace?

It’s a good start.

Image by Meigs O’Toole