Detectors use sound waves to irradiate IEDs

The work is being conducted as part of the $7m (£5m) Multi-University Research Initiative (MURI), led by North Carolina State University and funded by the US Office of Naval Research. Purdue will receive $2m over five years.

The researchers will study how to use sound and radio waves to irradiate objects, producing a new set of waves that reflect back to identify underlying materials.

Computational models and mathematical equations will be developed to enable the technique to work in real time to quickly detect explosives. 

‘You want to get energy into the material, have it move around to pick up information and then be reradiated so that we can sense what’s inside,’ said Douglas Adams, Purdue’s Kenninger professor of Mechanical Engineering.

A central challenge is learning how to interpret signatures created when high-amplitude waves, such as those emitted by loudspeakers, pass through objects made of several layers or components containing different materials.

‘Most materials are relatively linear, meaning they respond in an easily predictable way when excited by low-amplitude waves,’ said Adams. ‘But with high-amplitude waves, material behaviour is much more complicated, or non-linear, so we can’t use the same mathematical equations and models to describe how the waves propagate inside the materials.’