Sandia National Laboratories 3D Printing Tamper-Indicating Enclosures

Scientists at Sandia National Laboratories are researching improved methods of monitoring and inspecting enclosures, with new systems that visualize molecular changes, alerting users to an issue with a specific area that may have been breached. Their findings are outlined in ‘Tamper-Indicating Enclosures with Visually Obvious Tamper Response,’

With the use of progressive ‘bleeding materials,’ Sandia National Laboratories is creating methods for inspectors to realize penetration of material simply by looking at a tamper-indicating enclosure (TIE). Today, most traditional methods rely on high-maintenance, time-consuming examinations by inspectors. They may also use cameras, or other equipment or approaches.

General schematic of R&D concept. A two-phase material consisting of a sensing polymer and transition-metal encapsulated microspheres are 3D-printed or spray-coated on to a unique geometry. Upon tampering, the microspheres rupture and the two sensor components interact to form an irreversible visible color change.

Securing whole volumes includes:

• Enclosures that are non-standard in size/shape.
• Enclosures that may be inspectorate- or facility-owned.
• Tamper attempts that are detectable but difficult or timely for an inspector to locate.
• The requirement for solutions that are robust regarding reliability and environment (including facility handling).
• The need for solutions that prevent adversaries from repairing penetrations.

In creating a new method, the scientists explored the idea of 3D printing microspheres that would become discolored upon a breach. They also explored a spray coating formulation, with typical TIEs falling into three categories of use:

• Materials the inspector visually examines
• Active electronics methods/materials
• Externally deployed indicators of penetration or access to materials

“The limitations to these three categories are the subjective and time-consuming process of visually inspecting surfaces, the inability to deploy an active approach in some situations because of batteries or because of environmental conditions or facility requirements, and the limited materials able to be analyzed by eddy current and potential inability to bring external equipment into a facility. Further, some approaches rely more on post-mortem analysis rather than in-situ verification,” said the researchers.

The researchers envision a 3D printed material adding substantially to the TIE toolbox—currently ‘limited in options.’ It will also be available for customized inspection equipment, as well as spray coated equipment. The team expects 3D printed prototypes to be subjected to a range of environmental assessments, along with testing regarding durability and vulnerability levels.

Urea Formamide (UF) performed the best in terms of materials performance. The researchers noted details such as a ‘robust’ synthetic method, narrow size distribution, uniform particle properties, along with good compatibility of mobile phase materials which the team had already tested.

 “The anticipated benefits of this work are passive, flexible, scalable, cost-effective TIEs with obvious and robust responses to tamper attempts,” explain the authors in their abstract.

Viable applications for this technique could include:

• Custom TIEs
• Spray coating on items or structures
• Spray coating of circuit boards
• 3D printed seal bodies

3D printing has opened a wealth of knowledge about the countless materials available to scientists today seeking to improve industrial and other applications. Monitoring and sensing devices are becoming extremely popular in the 3D realm also, allowing for better performance of machines and higher quality prototypes and parts. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

Qualitative scoping study results on 3d transition metal color changes with the addition of organic sensor in methanol. All metal solutions get significantly darker, and many have a dramatic color change.