Some of that work is being done by the U.S. Army Armament Research, Development and Engineering Center, or ARDEC, based at Picatinny Arsenal, New Jersey.
One example is the Small Arms Deployable Sensor Network which allows intelligence gathering from inside a building without entering the building. ARDEC has developed wireless sensor nodes (WSNs) that can fit into a small-arms round and be fired into a building, according to a report on the ARDEC website. The WSN includes microphones, a magnetometer, a still image camera, GPS and a mesh radio network. These would then be able to sense and report the presence of people in the building.
Other examples are the development of proximity sensors small enough to fit into 30mm caliber ammunition, guidance and control systems that fit into 40mm projectiles, miniature laser igniters for small caliber ammunition and small, high-density power sources.
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