System Bits: Sept. 8

Engineering verifies disarmament agreements
While it might sound a bit far fetched at first glance, an MIT PhD has developed a tool to identify nuclear weapons.

Ruaridh Macdonald, now working on a nuclear weapons verification project in the Laboratory for Nuclear Security and Policy, whereby the linchpin of disarmament agreements is to be able to verify that the signers are following the rules. The trick, he said, is for both sides (or a third party) to be able to police weapons in a way that doesn’t give out too much information about them. If the U.S., for example, were to inspect a Russian weapon, in the process they might also be able to gather valuable information about how it was built — not information that governments want other countries to have.

Macdonald is involved in a project, called Zero Knowledge Warhead Verification, that tackles this problem with a beam of light, a scrambler, and a detector. Objects are made up of nuclei, which each give off a unique glow when hit with a gamma ray; the specific glow of an object acts like a fingerprint to identify what isotopes it’s made of. By carefully repeating this process from multiple angles, a nuclear weapon can be identified based on the composition and distribution of its isotopes.

To provide just enough of this identifying information, but no design information on a weapon, the weapon is illuminated by the gamma ray beam; the resulting information is then passed on to a scrambler that mixes up the signals before reaching a detector. The resulting signal is then compared with one from a known weapon to see if they match. As both signals are scrambled, the inspector learns nothing useful about either, preserving the owner’s secrets — similar to the idea of “hashing” in digital cryptology.

Macdonald and his colleagues are also working with Department of Energy labs to design such a verification device.

Compostable electronics
According to researchers at Karlsruhe Institute for Technology (KIT), every year, almost two million tons of electronic scrap arise in Germany. They believe printed electronics enhance the trend to throw used devices away by reducing production costs and opening up new markets with disposable items, such as interactive packagings or smart band aids. As such, the researchers have developed printed electronics made of compostable natural materials and processes for industrial production.

The researchers used easily biodegradable materials to create semiconductors and dyes made of plant extracts or insulators made of gelatin. While they may not be as long lived as inorganic materials, they easily survive the service life of disposable electronics since after use, the electronics can simply be thrown away into the biowaste bin or on compost heaps, where it will rot like a banana skin.

Organic light-emitting diodes (OLED) can be produced easily and at low cost. Thanks to compostable materials, they are also made sustainable. (Photo: KIT)