One of the greatest bottlenecks of current security screening technologies at places like airports and courthouses is the need to remove and scan shoes for each individual. Current screening devices, most developed using PNNL’s patented millimeter-wave technology, scan for objects such as weapons, explosives, or contraband under a person’s clothing. However, they are not designed to detect objects hidden in heterogenous environments like shoes, which typically contain many layers of different types of materials.

Using decades of experience with millimeter-wave technology, PNNL has developed an approach to scan under a person’s feet for concealed objects in footwear, with no need for removal.

The innovation uses low-profile millimeter-wave antenna arrays that could be integrated into the millimeter-wave technology floor to scan the soles of individuals’ shoes as they pass through the system. A transceiver applies electrical signals to the arrays, which transmit electromagnetic waves through the scanner floor into the footwear and receive those waves back. Processing algorithms analyze the results and relay information regarding the contents of the footwear to security personnel for action. The approach can detect objects concealed in heterogenous articles such as shoes, boots, sandals, flip-flops, and moccasins. This innovative technology could be used in-line with other screening technologies and integrate with existing and future system architectures.

With recent advancements (U.S. Patent Application 16/894,484), modified geometry uses a new scanning mechanism to significantly improve the performance, cost, and ease of integrating the millimeter-wave shoe scanner system. This invention modifies the original scanning arrangement by using rotationally scanned linear arrays. A rotational scanning configuration will allow integration into the floor of cylindrical mm-wave body scanners. The rotational scanning hardware can be reduced in height compared to other arrangements, allowing for integration into existing scanning form factors.

The millimeter-wave shoe scanner system addresses federal and industrial security requirements and can likely be manufactured inexpensively, making it an ideal candidate for threat detection at aviation checkpoints, public arenas, courthouses, concerts, and other locations requiring screening security for individuals.