Objective

Businesses must develop materials and an approach to manufacturing ballistic protection eyewear lenses with integrated prescription correction suitable for point-of-need additive manufacturing.

Description

Combat eye protection is a ubiquitous need for all deployed Soldiers. The eyewear provides the wearer protection against ballistic-fragmentation and environmental concerns, such as blowing sand, while remaining transparent to retain situational awareness. Manufacturers currently make protective eyewear lenses via injection molding and are not easily customized to provide vision correction.

The Universal Prescription Lens Carrier provides any needed prescription vision correction. The UPLC sits behind the primary protective lens and contains a separate set of corrective lenses specific to the user’s vision correction needs, while mounted into the UPLC frame. This creates integration issues for equipment worn on the face and eyes, while limiting the field-of-view through the prescription lenses and adding substantial logistical burden.

The Army product manager for Soldier Protective Equipment has an ongoing initiative to identify technologies that would allow for the elimination of a separate vision corrective lens (such asan integrated vision correction or  ballistic protection lens). These lenses have a life cycle of less than six months since ballistic eye protection lenses are often rapidly degraded in combat environments due to scratching and abrasion.

It is also desirable to have rapid turnaround on individually customized corrective lenses and to limit the logistics burden by providing manufacturing capability that is close to the point-of-need, as well as being customizable to an individual wearer. An additive manufacturing method is most likely to meet these requirements. As AM technologies have progressed, printing resolution and material development have improved to the point where optically-clear samples are now achievable.

The cost of this technology has also decreased, resulting in a commercially-viable approach to manufacturing custom lenses. Companies in this space are continuously developing new materials for their 3D printers to impart performance that was only attainable with conventional manufacturing methods. However, the expanded use of augmented reality in both military and civilian sectors spurred advances in optically-clear and durable eyewear manufactured with AM.

The Army wants to develop materials and processes to rapidly manufacture a customized optical lens that meets all requirements of MIL-PRF-32432A for ballistic protection lenses. It also wants to provide excellent optical quality, dimensional tolerances and stability in all environments to provide vision correction.

Phase I

The vendor must develop the materials and AM processes needed to fabricate flat plaques that are optically transparent (>89% luminous transmittance, with less than 3% haze and minimal optical distortion), yet provide ballistic protection as outlined in MIL-PRF-32432A.[4]

The business should also demonstrate that the cured plaques remain optically transparent and maintain impact resistance across a range of humidity (35-95% ± 5%), temperature (-60 °F – +160 °F), exposure to solar radiation and common military chemicals to include: 6.0 % by weight sodium hypochlorite, insect repellent-controlled release diethyl toluamide (30% concentration DEET), fire resistant hydraulic fluid (MIL-PRF-46170), hydraulic fluid, petroleum base (MIL-PRF-6083), gasoline (87% octane), motor oil (SAW 10W-30) and F24 fuel (NATO Standard AFLP 3747). It should also offer resistance to scratching, abrasian and fogging, as required by MIL-PRF-32432A for currently fielded protective eyewear. Some possible candidate materials to achieve this balance include acrylics, urethanes and polycarbonates.

Companies making and selling 3D printers and resins may not fully specify the formulation of their products due to proprietary restrictions. So, in-house resin development may be necessary.

Phase II

Businesses must optimize materials and processes that allow for AM of optical quality structures that meet minimum MIL-PRF-32432A requirements for luminous transmittance, optical clarity and ballistic performance as outlined in MIL-PRF-32432A for military eyewear. The materials should be compatible with standard commercial-off-the-shelf AM systems (dynamic light projection, stereolithography, etc.) without needing customization.

Printing of eyewear lens prototypes should be achievable in less than three hours with sub-100 µm printing resolution and allow for printing of a “one-off” lens that demonstrates custom vision correction. The company must demonstrate the optical transparency and ballistic protection of the resulting cured eyewear prototypes, as well as the fidelity of the printed and cured part of the original design.

The business should demonstrate the utility of this approach by printing a range of lenses with incorporated vision correction covering a range of –10.00 to +8.00 diopters, with up to -3.25 diopters of cylinder. Example lenses shall at a minimum include prescriptions at +8, -10, +5, -5, +1.5,-1.5 diopters, as well as a non-prescription optically-corrected variant for comparison.

Prescriptions shall be reasonably accurate (within 0.25 diopter) as measured on a lensometer. Lens designs shall maximize field of view through the lens and offer peripheral protection. The Army encourages offerors to partner with a protective eyewear supplier early on in the effort.

Phase III

The development and maturation of this technology will allow for integrated sensory protection and vision correction for the wearer. This advancement will enhance situational awareness of the wearer by enabling customization for optimal vision correction not currently available in fielded products.

It also reduces the logistical burden and timeframe needed for the replacement lens to reach the point-of-need and support the DoD’s National Defense S&T strategy. It will create and field capabilities at speed and scale through the innovation of industrial processes.With this technology, there is significant benefit to the civilian sector for not only protective eyewear, but eyewear in general.

The customization achievable with this approach would ensure wearers of every head size, shape and prescription could obtain the best vision correction possible. Specifically,  safety, sports and augmented reality areas would benefit from this technology development.

Submission Information

All eligible businesses must submit proposals by noon ET.

To view full solicitation details, click here.

For more information, and to submit your full proposal package, visit the DSIP Portal.

STTR Help Desk: usarmy.rtp.devcom-arl.mbx.sttr-pmo@army.mil