New devices that scan bottles and shoes for bombs are being developed in the US.

Clint Seward’s bottle-screening machine, about the size of a laptop, fires microwaves through glass and plastic bottles to detect flammable liquids such as kerosene and nitroglycerin.

Another bottle-scanner compares a liquid’s molecular structure to a library of about 30 combustible liquids installed in the machine’s software.

GE Security designed a Shoe Scanner that will speed up the passage through checkpoints. Instead of removing shoes, passengers would stand on a machine for a few seconds while a highly sensitive radio-frequency coil looks for explosives.

Current machines have drawn complaints at airports for scanning luggage too slowly and delaying flights. The problem: TSA luggage scanners use X-rays to look inside bags. They identify possible explosives by their density. That causes a lot of false alarms for objects such as peanut butter and requires a security screener to inspect every suitcase that sets off an alarm.

CyTerra is building a machine that uses pressure to squeeze explosives particles out of aluminum containers that hold up to 100 suitcases. Hundreds of bags could be checked in minutes.

Physicist Bogdan Maglich proposes another solution — the same one used by the U.S. military to find buried land mines. His machine finds suitcase bombs in 6 to 10 seconds by analyzing the chemical composition of materials.

Via USA Today.