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.
Next: MEMS in extremis
Safe-and-arm devices make sure that projectile fuzes only become armed and detonate under specific conditions and with modern electronics those conditions can be increasingly complex using MEMS and electronics. Often the MEMS use metallic LIGA (Lithographie, Galvanoformung, Abformung) for reasons of structural strength.
An artillery fuse can be designed to arm only after experiencing the extreme acceleration of gun-launch and the intended spin rate and traveling a safe distance from the artillery gun crew. Precision munitions often have additional safety features in the fuze firing circuit to assure the projectile is properly guiding before becoming fully armed (see
ARDEC is designing safe-and-arm devices based on MEMS and that require high voltages to detonate. These systems move away from traditional mechanical safe and arm devices that would use clockwork mechanisms to slowly rotate detonators to be in line with the rest of the firing train.
ARDEC said it has successfully demonstrated MEMS fuzing in 155mm and 40mm projectiles and is currently working on manufacturing technology for production transition.
ARDEC has also implemented silicon-based MEMS technology for inertial measurement units for guided projectiles such as Excalibur. The US Army is replacing larger devices based on air-bearing gyroscopes and ring-laser gyroscopes for the inertial guidance reference in precision munitions with silicon MEMS IMUs.
“We are using similar sensors to what you would find in game controllers or in your phone, just more reliable,” said William Smith, the director of fuze and precision armaments, in a report. However, such IMUs need to be able to withstand accelerations up to 15,000 Gs in gun-launch environment.
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