Use of dogs (K-9s) are one of the best methods for detecting explosives. To affectively use dogs, scent training is required to recognize targets routinely. The effectiveness of the ability to detect derives directly from training. Training aids (materials that resemble explosives) are key to this. Dogs are trained on objects that have low concentrations of explosives, called training aids. These aids must be high fidelity and not have volatile contaminants because K-9s are easily trained improperly on contaminants.

K-9 training aids for explosives are commercially available but there are few real manufacturers. Although the training aids are not considered hazardous materials, production is limited to few that can handle and manipulate raw explosive materials. Because of the nature of the production of the aids, they come in limited forms and shapes (mostly powders or pastes). They are generally mixed with inert substances but the selection is limited because of manufacturing methods, volatiles and interferents from the matrix.

Additive manufacturing is a recently developed approach to making materials that differs from other synthesis methods such as mixing and curing, melt casting, and pressing. The technique allows production of objects with unique properties. Objects are formed by layering slurries that have modified flow properties. The technique has great flexibility to produce objects in wide variety of shapes, sizes and compositions that have not previous been accessible. Recently, technical developments have been made that allow the printing of high concentrations of explosives mixed with matrices.

This technology now has been applied to producing K-9 training aids for explosives to overcome the issues of currently available training aids—target explosives are limited, substrates to hold the explosives are limited, shape variation of the aids is highly limited.

Type of traditional explosive can be addressed (PETN, RDX, TNT, etc.), but also improvised explosives formulations (oxidizer and fuel) can be made because layered structures (by way of AM methods) keep oxidizer and fuels separate but in the same part (without reaction). Construction of any shape or size (dog bone to cell phone case or bigger) is also possible. Wide variety of matrices available (more realistic for training)—essentially anything that can be printed by AM methodology. As with traditional methods, the aids are made safe to transport and handle as non-hazardous materials.


This technology uses AM printing methods applied to explosives materials. But unlike producing explosives parts, the explosive component is added at a low concentration of around 4 to 6 wt. %. This allows for the final form, to be labeled as a non-hazardous material. A suitable matrix (substrate) is selected that ultimately will be non-volatile (reducing improper training on contaminants) and meet the application of the user. The mixture is printed in to the shape needed cured if necessary (depending upon the matrix). If the target aid is an improvised explosive (mixture of an oxidizer and fuel), each component will be printed in separate layers with non-loaded layer in between. This will prevent mixing of the two components causing reaction. The aid is now ready for distribution to the customer and can be shipped without special handling or storage.

For more information: K-9 Training Aids for Improvised Explosives by Additive Manufacturing


This technology is applicable to producing K-9 training aids for explosives, drugs or other materials for which dogs are used to detect. Commercial entities that currently produce K-9 training aids could add this technology to their portfolio and widely broaden: 1) the types of explosives incorporated, 2) matrices or substrates that can be used with the explosive, and 3) shapes and concealment of the aids.

This manufacturing can be expanded to other targets such as illicit drugs or environmental chemicals, anything that can be printed in AM. Other applications include solid state sensors that have chemical specific detection elements. For example, solid state sensing is used for some colorimeter detection of explosives. The component materials for these sensors often meets dispersion issues in the manufacturing of the sensor element. The AM method for these would improve uniformity in dispersion and possibly improve sensitivity and detection limits.

Potential Applications

This technology has benefits over existing technology because it facilitates production of K-9 training aids for explosives with explosives and substrates that cannot be done currently with existing production methods. For conventional explosives, the technology primarily broadens the types of explosives accessible, but more importantly the substrates that the explosives are on. Most training aids are limited to silica or petroleum gel for substrates, limiting applications. This recent technology will allow a much broader range, such as localized dirt, for an example. For improvised explosives, this technology allows for making virtual mixtures of the components without the mixtures reacting. Laminated printed materials now can have an oxidizer and a fuel, critical for improvised explosives, in the same object without them reacting (making an explosive mixture). In addition, AM printing will provide objects of any configuration that can be printed, with the explosive component in it. All these features are superior improvements over existing technologies.

Development Status

K-9 training aids with low concentrations of HMX have been printed and are in the prototype stage. Small prototype objects have been taken to completion using Si-based polymer substrates. The intellectual property has been submitted in two patent applications.

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