Since the nature and contour of the 21st century battlefield is changing very fast, the rapid introduction of new technologies and state of the art research and development in this segment could alter the present approach by invigorating the soldiers into a superhuman who will fight the war on ground.
Soldier modernization programs have often focused on equipping soldiers with new technology in the simple belief that more information and functionality will result in a more effective soldier.
Clearly, any equipment providing increased situational awareness, more accurate observation and target information, and enhanced communication and navigation will improve a soldier’s effectiveness.
However, there is a trade-off between equipment load and combat effectiveness. The weight and power consumption of most equipment packages for command & control and situational awareness have typically been unacceptably high.
That something is technologically possible and probably the least important reason for adding functionality.
Yet, the latest surveys suggest that global soldier modernization market is expected to be worth US$11.3 billion in 2016, and is expected increase to US$22.8 billion by 2025.
Indeed, infantry equipment has not improved much in the inter-war years or between the Korean War and the end of the Cold War. In fact, WWII advances focused on weapons and ammunition while Cold War developments focused on lighter rifles and better grenade projection capability.
The accumulated opportunities for technical improvement and the concentration of ‘few casualties’ wars with highly trained infantry allowed for major modernisation efforts in the 1990’s.
These modernization efforts included clothes/bags, camouflage patterns, weapons, radios and even computers. The tank technology competition between NATO and Warsaw Pact had lost relevance.
Today, the typical US combat soldier wears 80 pounds of gear in the field. Given the desert and urban warfare conditions in which current campaigns are being conducted and the physical demands of those types of combat, excessively heavy personal gear slows down the wearer and can be a significant contributor to wearer fatigue.
Extra weight in ground soldier gear not only detracts from the soldier’s performance, but is also potentially life-threatening.
According to reports, the US Department of Defense has set the objective of removing 20 pounds of weight from each ground soldier’s equipment ensemble (GSE).
Given that each soldier wears a backpack, IOTV body armor, and carries weaponry and ammunition, finding that 20 pounds of overall weight reduction will require re-thinking the design and packaging of many types of electronic and communication equipment.
Many of the historically accepted approaches to designing and manufacturing combat equipment simply cannot meet the mandated challenge of a 25 percent reduction in GSE weight.
This document reviews four new manufacturing technologies that can be used by defence industry providers and also looks at several potential applications where those technologies might be applied successfully to meet requirements for high performance and light weight.
The simplest method for reducing weight in GSE equipment is to replace conventional materials with new technologies.
Approached properly, redesigned equipment cases, housings, and internal components can offer significant weight savings, while at the same time performing much better than their predecessors in areas such as water proofing, impact and shock resistance, and overall durability. Part reduction can be a major contributor to weight reduction.
Component miniaturization offers the single greatest opportunity for reduced equipment weight. In general, properly designed and manufactured molded parts can be expected to outperform conventionally produced components in all desirable areas.
Higher end-product quality, better performance, cost-effective production methods, and speed-to-market are also important considerations when meeting the military’s stringent requirements for new gear.
Among material replacement technologies, four methods are emerging as the leaders for weight savings and product performance.
Magnesium Injection Molding (MAG) demonstrates excellent performance in military communication gear.
The metal is equally as durable as aluminum, but is significantly lighter. Magnesium also has the same EMI (electromagnetic interference) and RFI (radio frequency interference) shielding properties as aluminum, but with thinner wall sections and reduced weight.
Thus, a magnesium housing for a communication device will perform better than an aluminum housing, yet at a 30 percent comparative weight saving.
Magnesium injection molding uses a thixo-tropic process, which combines the best qualities of plastic injection molding with die casting to produce lightweight, high-density, net shape metal parts.
Components produced using MAG demonstrates excellent properties for both stiffness and strength-to-weight. Parts can be designed in a wide array of sizes, ranging in weight from 4 grams to 1800 grams.
Plastic can be over molded on the magnesium parts depending on design requirements, and coating techniques can be introduced to prevent corrosion from electrolytic and atmospheric factors.
In the MAG process, chips of magnesium are fed into a heated screw and barrel, where the alloy is thermally and mechanically processed into a semi-fluid state, which permits it to be injected directly into the tool cavity.
Compared to die casting, MAG processing is done at temperatures more than 100ºF cooler. The cooler temperature allows the metals to remain in a semi-solid state, so they behave like thermoplastic for more controlled, laminar flow.
MAG generates net shape components with superior straightness and flatness, improved heat dissipation, and low porosity, while maintaining tight tolerances.
The added precision may reduce or eliminate the need for secondary machining operations. Insert molding of other metals into MAG components can be accomplished with virtually any type of insert, provided the insert does not have a lower melting point than the magnesium alloys.
Good design practice can eliminate visible parting lines on critical surfaces. The MAG process is also environmentally friendly, since material is recyclable and no ozonedepleting gases are used in molding operations.
Note that fears about the flammability of magnesium are based on flawed preconceptions and are largely unfounded.
Laboratory tests using direct flame application have demonstrated that magnesium does not ignite until the material reaches approximately 875°F, and does not sustain combustion independently once the flame is removed.
Metal Injection Molding (MIM) Metal injection molding (MIM) produces parts with complex geometries, superior strength properties, and excellent surface finish, with high volume manufacturing capability.
Total cost savings depend on shape complexity, production volumes, the size of the parts, and the materials used.
Among many advantages of MIM, it is common to be able to produce precision shaped parts from a variety of materials for 50 percent less than the cost of comparable CNC machining or investment casting.
Finished parts have the same mechanical properties as parts produced by machining. Parts produced using MIM can be up to 150 grams, but most MIM parts are less than 30 grams.
Very small metal parts can be created using the technology, with total volume of as little as 0.0001 to 0.003 cubic inches, while tolerances can be held as tight as plus or minus 0.001 of an inch.
Tighter tolerances can be achieved with secondary machining processes on critical dimensions. Density and mechanical properties in the finished part are approximately 98 percent of wrought.
The MIM process begins with the formulation of feedstock or raw material. Very fine metal powders (particle size less than 20 microns) are hot-mixed with polymeric binders to create a uniform mixture.
The mixture is then cooled and granulated to form feedstock for the injection molding process. Advanced instrumentation and control software monitors the process to produce consistent components with minimal density variation.
Heavy to light
If the molding cycle varies from predetermined tolerance limits, a closed-loop feedback system rejects parts automatically.
Complex contours, holes, small radii, logos, and text can be molded into the part during the process. Proper attention to detail in the molding process assures that all parts and the process will be consistent.
MIM is also an efficient and environmentally friendly process, as molded runners can be reground and molded again with no compromises in the properties of the part. After molding, catalytic debinding is used to remove 90 percent of the binder material from the green part, creating a “brown” part.
The main advantage of the catalytic process is that the brown parts have superior strength as opposed to a thermal debind process. There is also minimal distortion as the debind process occurs at a significantly lower temperature.
After debind, approximately 10 percent of the binder remains that allows the part to maintain its shape. In the final operation, brown parts are sintered using temperature and atmospheric profiles designed specifically for the alloy being processed.
During the initial stages of sintering the remaining binder is removed from the material. The parts then transition to the high temperature sintering zones where they are fully densified and final density of 96-99 percent of theoretical is achieved.
Tolerances are maintained by predicting linear shrinkage rates and over sizing the mold cavity to compensate. MIM can be used to produce parts from stainless steels, titanium, Kovar, nickel steels, tools steels, tungsten, super alloys, and soft-magnetic alloys.
Micro Molding Micro molding maintains the highest precision tolerances to produce finished parts as small as a pinhead.
Parts measuring only 0.020 inch per-side can be molded, and even smaller parts may be possible depending on the application. Details such as undercuts, threads, and thin wall sections down to 0.002 inch are possible, depending on component size and mold gate location.
Mold gate diameters down to 0.006 inch are possible. In designing lighter-weight combat soldier equipment, miniaturization is key. Micro molding technology aids in developing smaller and lighter end products.
Using micro molding, parts can be market-ready in as little as two to four weeks, depending on complexity. Finished part tolerances can typically be held within plus or minus 0.0003 inch.
Micro molding yields a larger proportion of finished part to molding runner compared to conventional molding, maximizing material usage while minimizing waste. Clean room manufacturing is absolutely necessary for making micro-sized parts.
Another advantage of micro molding is low cost. The investment necessary to produce a part is generally several times lower than that required for conventional injection mold tooling.
Usually, prototype tooling can be used in final production, with no further investment necessary if the final product design does not change. By contrast, conventional molding operations would require retooling for final production, with concurrent additional investments of money and time.
Multi-shot liquid silicone rubber molding (MS LSR) traditional thermoplastics and liquid silicone rubber can now be combined in one molded part, allowing fast, cost-effective production of complex components using multiple materials in the same mold.
Multi-shot liquid silicone rubber molding (MS LSR) allows a conventional thermoplastic part (made from PC, PBT, PA, and resins) to have silicone rubber added as seals and other components.
The resulting parts can be designed to have superior biocompatibility, chemical resistance, clarity, and the ability to withstand harsh environmental conditions.
Adding LSR to thermoplastic parts incorporates several desirable properties. LSR can accept a wide range of colorants, and it has high temperature resistance up to 410°F (210°C). LSR can also provide bacteria resistance, gas permeability, and excellent light illumination.
The MS LSR process can also be used to combine two different types of silicone in the same part for options including dual durometers, colors or additives. MS LSR is also excellent for end-user ergonomics, as the result is a comfortable, soft feel that works well in many user interface applications (from 10-80 shore A durometer).
For the designer, liquid silicone rubber allows “violations” of many accepted rules of thermoplastic molding.
For one, mold filling is less difficult, as variations in mold thickness are not an issue. Radii, draft, and undercut designs can have great flexibility, and do not require separate movement in tool design.
Multi-shot molding removes the need for assembly of plastic to silicone using either automated processes or hand labor.
MS LSR molding eliminates priming operations needed in conventional LSR over molding. Costs for primer and labor are thus greatly reduced, and environmental disposal concerns are eliminated. MS LSR is also a less temperamental operation, because it is less sensitive to fluctuations in weather and humidity than other methods.
Many thermoplastics can be used in the MS LSR process. The thermoplastic must have sufficient heat resistance to withstand the 300-400°F mold temperature in the silicone section of the mold.
Higher heat thermoplastics will be easier for tooling because of lesser difference in thermal expansion between the hot and cold sides of the mold. LSR generally requires lower injection pressure, but has a slightly longer cure time than the accompanying thermoplastic.
Military radios are needed for ground troops typically operate on the UHF band with transmit power between 5 and 25 watts.
Wearable antennas are needed in multiple configurations for diverse purposes, including integrated helmet and fabric antennas.
Radiation patterns and gain should be comparable to (or ideally superior to) a whip antenna. No snag hazards are acceptable, breakaway connections may be necessary, and designs that do not require wiring to the helmet are preferred.
Mobile battery recharging devices are also required. Longer ground mission duration requires man-packable recharging systems for lithium ion batteries used on communication gear.
Recharging systems must be sufficiently light in weight that they can be easily carried by ground soldiers, while being durable enough to withstand the rigors of combat environments.
To date, vehicle-based recharging systems have been used, but longer missions require portability. Technologies being considered for this application include solar power, fuel cells, power scavenging from potentially available sources, and energy harvesting from the mechanical energy of human motion. Soldier-worn information displays are also important.
These must be compact, lightweight, include a color screen, be rugged, consume minimal power, and be capable of displaying camera images, video, maps, and GPS data.
Besides, wireless PAN (Personal Area Network) can be handy. Computer systems worn on the body require wireless networking technology that has a range of one to two meters (additional range is a negative), is un-hackable and difficult to jam, has transceiver power of less than one watt, has a low probability of intercept and detection, and can be powered externally from 10 to 18 VDC.
Then wired and wireless input devices can change the weight ratio. Focus for these devices should be on small size, minimum weight, and ergonomic design. Functions include cursor control devices such as joysticks, force buttons, etc.; discrete buttons and switches; mini keyboards; and system access control device readers.
An advanced user input device should include mouse-like cursor functions, talk group selection, activation of radio push-to-talk controls, data purging for security, texting, and power activation/deactivation.
Moreover, soldier-worn computing is also needed. Both headless computers and computers with integrated flat panel displays are needed in configurations that will allow them to be worn as part of a soldier’s load-carrying ensemble.
In addition to processing and memory requirements (including support of both Windows XP and Linux operating systems), these units must be lightweight, have a small footprint, be rugged in design, externally powered from standard Land Warrior batteries, and be passively cooled.
Soldier-worn video receiver is making inroads into the warzone. These units must receive four channels of analog video to allow the soldier to select one of interest, then output the chosen channel in analog or digital video format via USB.
The purpose is to let dismounted soldiers view commonly used UAV, UGV, robotic, and ground sensor video signals. Units must be small, rugged, and have low power consumption requirements.
Also, integrated targeting device used for close air support (CAS) is very significant. This is a highly compact, lightweight device for geolocation, ranging, and target designation.
In addition to a range of other design requirements, these units should also be compact, lightweight, and consume minimal power.
The intent is to provide an integrated system that includes all needed functionality in a single, lightweight, compact, man-portable device that includes an integrated power source. BRITES battery recharger can enhance back up. This recharger would allow soldiers and airmen to recharge common form factor batteries (e.g. AA, AAA, and Surefire type rechargeable batteries) using 15 VDC produced by the BRITES apparatus.
The Battery Renewable Integrated Tactical Energy System (BRITES) provides energy collection, storage, distribution, and recharging in austere environments over long periods of time.
The system does not currently have the capability to recharge common commercial batteries used in tactical electronics. The recharging device must be rugged, lightweight, and in use should occupy a volume only slightly larger than the batteries being charged.
The device should also have minimal volume when stowed. Engineering Considerations Changing Technologies and Approach Making the transition from machined or stamped metal parts to new molding technologies requires a gestalt switch in the ways engineers look at designing and building assemblies.
The principles and rules that apply to stamping and machining parts often have little in common with what’s required to produce molded parts that return optimal functionality and durability.
It may be that the engineer will need to forget everything he or she thought they knew about designing and building parts when making the change to new material technologies.
Seeking design assistance from suppliers of technologies and materials is a wise idea. Companies that provide the new technologies covered in this document have extensive experience in helping their customers integrate new methods into their design processes.
Often, regardless of how extensive an engineer’s experience might be in other areas, the fine points of new design and manufacturing techniques will probably not be immediately clear. Molding parts introduces a broad range of variables into the design equation. Generally the help of an expert molder is needed to help increase the engineer’s knowledge base, and to help ensure the new design will work properly without lengthy revisions.
Molding companies that have experience in material replacement across a range of industries are the best resources for help with new military product designs. The molding company you select should work closely with technical experts from its raw material suppliers, and should also have extensive tooling capabilities available.
The molder’s prototyping capabilities are critical to efficient part development. Rapid prototyping capabilities including stereolithography and machining should be available. The molder should also have secondary operations available to streamline the production process. Trimming, deburring, drilling and tapping, CNC machining, electroplating, assembly, and painting/decorating capabilities should be done carefully. Reducing vendors and steps in the development process shortens production cycles.
It is also vital that the molder have an in-house laboratory in order to perform microstructure studies on materials. This capability allows the molder to make very fine adjustments to the processes used.
For defence industry projects, quality and confidentiality are vital considerations. Only suppliers with ITAR (International Traffic in Arms Regulations) registration should be considered.
Ergonomics and Ease-of-Use Many designers of electronic equipment for ground soldiers focus on creating the highest functioning electronics package, but can tend to build the finished product into a conventional metal box.
That approach not only potentially adds weight to the product, but also has the effect of making the device less user-friendly for the troops who wind up using it in the field.
Remember, today’s ground soldiers are predominantly young people; they grew up using video games and are typically highly computer-literate. An ergonomic interface that resembles a modern gaming controller is far more likely to be used intuitively than an old-style rectangular housing.
A competent provider of molding and related services will also have extensive experience in product housing and packaging design, and they will prove a valuable resource in helping develop a final product design that best serves the end-user.
The 20-pound-per-soldier equipment weight reduction the US Department of Defense is seeking is achievable by introducing new design and manufacturing technologies reviewed in this document.
By applying new technologies, it will be possible to develop new military technologies that help ground troops do their jobs better while being less encumbered by their gear.
And by including providers of available new technologies in the development and design processes, equipment manufacturers can be more fully aware of what can be, while bringing superior finished products to market more quickly.
However, British defence giant BAE Systems is creating a series of tiny electronic spiders, insects and snakes that could become the eyes and ears of soldiers on the battlefield, helping to save thousands of lives.
Prototypes could be on the front line by the end of the year, scuttling into potential danger areas such as booby-trapped buildings or enemy hideouts to relay images back to troops safely positioned nearby.
Soldiers will carry the robots into combat and use a small tracked vehicle to transport them closer to their targets.
Then they would swarm into the building and relay images back to the soldiers’ hand-held or wrist-mounted computers, warning them of any threats inside.
Researchers hope they will eventually create machines that can fly like a butterfly. Plans for a creature that can crawl like a spider are said to be well developed, and researchers eventually hope to be able to create creatures that can slither like a snake or fly like a dragonfly.