ARDEC engineers advancing Component Miniaturization
Engineers at the U.S. Army Armament Research, Development and Engineering Center, or ARDEC, have been making advancements in an initiative called “Component Miniaturization.”
Its mission focuses on making armament systems more precise, energy efficient, scalable and effective by reducing the size of critical components in sub-systems such as safe and arm devices, electronics packages, power supplies and inertial measurement systems. Size reductions in one sub-system can have a positive effect on another.
For example, a smaller and more efficient electronics package design can reduce power supply demands as well as reduce the need for heavier supporting structures. The space savings and mass savings could then be used to add a larger explosive warhead or increase control surfaces for additional maneuverability. The reduced size and mass could also allow for additional portability to smaller calibers or to systems with greater launch velocities.
The initiative involves several discrete projects, some of which are described below:
ELECTRONIC AND CONTROL SYSTEM PACKAGING
ARDEC is moving forward, along with private industry, in reducing the size of complex subsystems.
Taking advantage of modern electronic fabrication techniques in the Fuze Development Center and other on-site facilities, ARDEC engineers and scientists develop prototypes that demonstrate the ability to transform larger subsystems to smaller calibers.
The Small Arms Deployable Sensor Network is one such example.
“This allows the Soldier to gather intelligence on a building without actually entering the building, so they don’t have to put themselves in harm’s way,” said William Smith, the Director of Fuze and Precision Armaments.
“Say you cleared a building, you could leave these behind, or you could shoot them in through the windows of the building and it would sense and report the presence of an intruder in the building,” said Smith. “It has microphones, a magnetometer, a still image camera, GPS and a mesh radio network.”
Other examples are the development of proximity sensors small enough to fit into 30mm ammunition, guidance and control systems that fit into 40mm projectiles, miniature laser igniters for small caliber ammunition and small, high-density power sources.
“The HyperX chip is a massive core parallel processing chip. Parallel processing is the coordinated and simultaneous processing of program segments by several different processors. The HyperX chip has up to 100 separate processors on a single chip, running as many as 25 billion floating point operations per second at extraordinarily low power levels,” said Smith.
This design significantly reduced the number of electronic components needed, resulting in a remarkable increase in processing efficiency.
The HyperX is useful in military applications where rapid image processing is essential, or when large data streams need to be handled as efficiently as possible.
For example, if the warfighter uses a sensor system to examine a target of interest across multiple frequencies, it would allow them to capture and process that data more efficiently. With radio systems, voice and data signals could be processed rapidly.
“We are trying to reduce the demand on Soldiers for extra batteries. Since the HyperX is low power, it will have a longer life and can operate multiple systems off a single power source without this processor being a significant draw on power,” said Smith.
MICRO-ELECTROMECHANICAL SYSTEMS FOR FUZES
Projectiles rely upon fuzes to safely initiate an explosive charge. Safe and Arm devices assure that projectile fuzes become armed and detonate reliably and only under specific conditions. For example, a safe and arm device in an artillery fuze would often be designed to arm only after experiencing setback forces of gun-launch and the intended spin rate after a safe down range 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. In efforts to remain one step ahead, ARDEC is designing smaller and highly reliable safe and arm devices for fuzes through Micro-ElectroMechanical Systems or MEMS components. ARDEC also designs Electronic Safe and Arm Devices (ESADs) that require high voltages to detonate in-line explosive components.
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.
“We are using some of the same fabrications techniques you would use for electronics to produce small mechanical devices,” said Smith.
One example the Fuze and Precision Armaments Directorate’s Fuze Division is exploring the application of metal-based LIGA ((Lithographie, Galvanoformung, Abformung (Lithography, Electroplating, and Molding)) MEMS technology for the fabrication of Fuzing Safe and Arm devices.
With MEMS, the traditional Safe and Arm devices can be reduced to a small fraction of their original size.
Physical space in munitions becomes extremely critical as small munitions become more sophisticated. The introduction of a MEMS-based and arm device in 40mm projectiles allows for additional space that could be used by a power sources, lethal mechanism, sensing electronics, propulsion or a control system.
ARDEC has successfully demonstrated MEMS Fuzing in 155mm and 40mm projectiles and is currently working on manufacturing technology for production transition.
While ARDEC is transitioning metal-based MEMS technology in fuzing, they have also successfully implemented silicon-based MEMS technology in Inertial Measurement Units for guided projectiles such as Excalibur.
MEMS IMUs have replaced larger devices such as traditional gyroscopes, air-bearing gyros and ring-laser gyros for the inertial guidance reference in precision munitions.
“We are using similar sensors to what you would find in game controllers or in your phone, just more reliable,” added Smith.
ARDEC, along with the U.S. Army Aviation and Missile Research Development and Engineering Center, managed the development of common IMU devices for a wide range of projectile and missile applications.
The Analysis and Evaluation Division developed detailed models that predict and display the forces acting upon these components in the gun-launch environment. These models were able to identify structural concerns, which were addressed to assure survivability under forces in excess of 15,000 Gs.
Research in IMU size reduction continues and some day may result in atomic-level IMUs.
GRAPHENE AND OTHER 2-D MATERIALS
ARDEC is exploring the emerging field of two-dimensional materials for armament system applications.
“We are looking at things now from an atomic level for the future of semi-conductors, specialty coatings, support structures and energetics,” said Smith.
“These materials, fabricated and operating at the atomic layer scale, have unprecedented future applications,” said Smith.
ARDEC has joined a two-dimensional research consortium sponsored by the National Science Foundation.
Research is conducted at the ATOMIC Laboratory, jointly established by Penn State and Rice University.
“We have also brought in exchange engineers from South Korea and Japan to help execute basic research in these areas,” said Smith.
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The U.S. Army Armament Research, Development and Engineering Center is part of the U.S. Army Research, Development and Engineering Command, which has the mission to ensure decisive overmatch for unified land operations to empower the Army, the joint warfighter and our nation. RDECOM is a major subordinate command of the U.S. Army Materiel Command.