US Government as Represented by the Secretary of the Army

Larry R Holmes, Jr

Eric Dean Wetzel

Frank Casper Tortella

Patrick M Toal, Jr

Zachary J Larimore

Deborah A Shear

Lai Yee Leung

Ricardo X Rodriguez

Mark W Brown

Xi-Chun May Lu

Jitendra Ramanlal Dave

Mark F Arnold

Kara E Schmid

Zhilin Liao

Jay E Bartlett

Mark P Easterday

Zhiyong Chen

Andrea Mountney

A thermoplastic filament comprising multiple polymers of differing flow temperatures in a regular geometric arrangement, and a method for producing such a filament, are described. Because of the difference in flow temperatures, there exists a temperature range at which one polymer is mechanically stable while the other is flowable. This property is extremely useful for creating thermoplastic monofilament feedstock for three-dimensionally printed parts, wherein the mechanically stable polymer enables geometric stability while the flowable polymer can fill gaps and provide strong bonding and homogenization between deposited material lines and layers. These multimaterial filaments can be produced via thermal drawing from a thermoplastic preform, which itself can be three-dimensionally printed. Furthermore, the preform can be printed with precisely controlled and complex geometries, enabling the creation of monofilament and fiber with unique decorative or functional properties.

Process for creating a polymer filament suitable for use in three-dimensional printing

A thermoplastic filament comprising multiple polymers of differing flow temperatures in a geometric arrangement and an interior channel containing a structural or functional thread therein is described. A method for producing such a filament is also described. Because of the difference in flow temperatures, there exists a temperature range at which one polymer is mechanically stable while the other is flowable. This property is extremely useful for creating thermoplastic monofilament feedstock for three-dimensionally printed parts, wherein the mechanically stable polymer enables geometric stability while the flowable polymer can fill gaps and provide strong bonding and homogenization between deposited material lines and layers. These multimaterial filaments can be produced via thermal drawing from a thermoplastic preform, which itself can be three-dimensionally printed. Furthermore, the preform can be printed with precisely controlled and complex geometries, enabling the creation of a filament or fiber with an interior thread contained within the outer, printed filament or fiber. This thread adds structural reinforcement or functional properties, such as electrical conductivity or optical waveguiding, to the filament.

Process for creating a filament

An apparatus and method for inflicting brain injury on a laboratory animal that employs a platform for supporting the laboratory animal. The platform defines an opening for positioning the head of the laboratory animal over the opening. A projectile is launched from a projectile launching device orientated below the opening of the platform. The projectile launching device has a means for propelling the projectile directly at and/or through the opening of said platform, thereby inflicting brain injury on the animal via either a pressure wave or concussive impact of the projectile. Without helmet, direct impact of the projectile results in severe traumatic brain injury. Use of helmet protects animals from skull fracture, subdural hematoma, intracerebral hemorrhage and contusion yet produces mild concussion-like pathology.

Device and method for inducing brain injury in animal test subjects

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Peach Bottom, PA, United States of America

Larry R Holmes, Jr