The United States Army is at it again. Just when you thought that they couldn't find another application for 3D printing, they seemingly have. It appears that the Army envisions a future in which 3D printing technology will be involved in everything from food for soldiers, to body armor, uniforms, and even replacement body parts.

Although it's seldom realized by the civilian population, a major cause of injury and even death from explosions occurs not from shrapnel, or burns inflicted on a soldier, but also from the damage done to the brain which shock waves cause from high impact explosions. When a high-order explosive goes off, such as C4 or TNT, their is a tremendous amount of pressure released. This over-pressurization can called a variety of internal damage to the human body, much of which is hidden. A solider may look fine on the outside, while he or she may be suffering from a severe concussion on mild traumatic brain injury brought on by the incredible pressure changes, and shock waves from an explosion nearby.

The U.S. Army Research Laboratory (ARL) recognizes this as a major safety concern, and has thus set out to determine the mechanisms behind these injury, as well as ways which we can protect out soldiers during combat.

To do this, they are use 3D printers to fabricate synthetic human skulls which react very similarly to an actual human skull during a blast. Prior to turning to 3D printing technology for this research, the Army considered using synthetic bones which surgeons are familiar with as tools for practicing surgery. They found that such synthetic bones were not ideal for this type of research, as they did not react to a blast liek that of an actual skull. They also considered using actual donor skulls, but found that the majority of these skulls were from older individuals, which did not represent the 20 and 30 year olds which generally are in combat. As the body ages, bones react to trauma differently.

This led the team at the ARL to turn to 3D printers for a solution. The solution which includes modeling and 3D printing synthetic bones in the laboratory, which reacts the same as a typical 20 or 30 year old individual's skull would to a blast, should allow them to develop protection for soldiers in combat

"The cranial bones have a highly-graded structure, from a tough outer layer, a spongy inner section, to a more brittle inner layer, which together are responsible for how it responds under impact conditions," said Dr. Thomas Plaisted, materials engineer in the Materials and Manufacturing Science Division at the ARL. "We are developing new helmet padding materials to improve the impact protection afforded by the Army's helmets. The helmet can withstand impact at a certain velocity while protecting the head from accelerations that would lead to injury. In the extreme case, excessive acceleration may lead to skull fracture."

Earlier in the year the the ARL team tested their first 3D printed synthetic bone against that actual bone. The test included hitting the synthetic bone at a high velocity, and comparing it to the fracture patterns of the actual bone. They determined that the synthetic printer bone was a 'close match'. Within the next few months ARL will begin using the printer bone for blast testing for the first time.

More details on this story as well as images can be views here: http://3dprint.com/11184/us-army-3d-print-skulls/