Smartphone-based nerve gas detector made from Lego bricks
Researchers from the University of Texas at Austin and Xi'an Jiaotong University, Xi'an, have channeled their inner MacGyver and come up with a simple, affordable and durable chemical weapons detector made out of an iPhone, a UV lamp, a standard 96-well test plate and … a bunch of Lego bricks.
Why Lego bricks and a regular smartphone? Because the current technology is far too expensive and unsuited to work in the field. The researchers wanted a device which would be portable, could be assembled quickly on the spot and made from readily replaceable components. The team originally considered a 3D-printed box but soon realized that 3D printers and the filament material can be inaccessible and/or cost-prohibitive in many parts of the world.
The Lego brick dark-box has a broad-band UV lamp at the rear, a door and ramp at the front for placement of the 96-well test plate and Lego bricks as guides on the top for the correct placement of the smartphone. The smartphone camera then captures the images for color analysis using free software.
While the MacGyver-esque build style is both ingenious and entertaining, the real hero here is the detection and analysis methodology.
Colorless, odorless nerve agents such as Sarin and VX rapidly shut down the nervous system, with death following soon after. In many instances, the victim only has seconds to live. Understandably, first responders need to be able to quickly identify which nerve agent is in play so that they can respond appropriately.
Time lost means lives lost.
The problem is that present methods aren't up to the task, so Eric Anslyn, Edward M. Marcotte and colleagues developed a new method of detection and analysis. Their setup not only detects and quantifies nerve agents at a contaminated site, but it distinguishes between the two primary classes of agent present (G-series and V-series) which require quite different decontamination methods. Something the current tools struggle to do.
The methodology relies on the optical signal created by the decomposition reaction of the nerve agents. Self-propagating cascades amplify this signal, with the resulting color and intensity being proportional to the type and amount of chemical weapon present.
Along with the use of cheap materials and free software, the researchers have chosen to place all of their analytic code, charts and guides on GitHub in the hope that this will encourage the rapid and broad adoption of the technology. Something MacGyver himself would approve of.
The research is detailed in a paper published by the American Chemical Society.
Source: University of Texas at Austin