Abstract: A photonic integrated circuit (PIC) structure includes an active region in at least an active layer over a substrate, the active region including a plurality of transistors therein. A plurality of dielectric interconnect layers are over the active region, and an opening is defined through the plurality of dielectric interconnect layers. The opening extends to at least the active layer. A barrier is within the plurality of dielectric interconnect layers and surrounding the opening. An optical element is positioned in the opening. The barrier prevents stress damage, such as cracks and/or delaminations, from propagating from or to the opening, and maintains the hermetic seal of the PIC structure.

Abstract: A photonic integrated circuit (PIC) structure includes an active region in at least an active layer over a substrate, the active region including a plurality of transistors therein. A plurality of dielectric interconnect layers are over the active region, and an opening is defined through the plurality of dielectric interconnect layers. The opening extends to at least the active layer. A barrier is within the plurality of dielectric interconnect layers and surrounding the opening. An optical element is positioned in the opening. The barrier prevents stress damage, such as cracks and/or delaminations, from propagating from or to the opening, and maintains the hermetic seal of the PIC structure.

Abstract: An auxetic polygonal cell may have a plurality of chiral structures capable of rotation. The plurality of chiral structures may at least partially enclose a volume. Each of the chiral structures may include a first cross member having a first set of distal ends and a second cross member intersecting the first cross member, the second cross member having a second set of distal ends. The chiral structures may also include a first set of legs, wherein each leg of the first set of legs extends from at least one distal end of the first set of distal ends and a second set of legs, wherein each leg of the second set of legs extends from at least one distal end of the second set of distal ends.

Abstract: An auxetic structure consistent with the present disclosure may include a core cell, capable of rotation, including a plurality of first rib sections, and a plurality of second rib sections. The first rib sections may be transverse to a longitudinal axis of the auxetic structure and at least one of the first rib sections may extend from the core cell. The second rib sections may be transverse to a transverse axis of the auxetic structure and at least one of the second rib sections may extend from the core cell.

Abstract: An auxetic polygonal cell may have a plurality of chiral structures capable of rotation. The plurality of chiral structures may at least partially enclose a volume. Each of the chiral structures may include a first cross member having a first set of distal ends and a second cross member intersecting the first cross member, the second cross member having a second set of distal ends. The chiral structures may also include a first set of legs, wherein each leg of the first set of legs extends from at least one distal end of the first set of distal ends and a second set of legs, wherein each leg of the second set of legs extends from at least one distal end of the second set of distal ends.

Abstract: A bi-axial testing apparatus, system and method may be used with known uni-axial material testing machines to perform biaxial displacement control (e.g., compressive and/or tensile) testing on a specimen. As such, the apparatus, system and method may be capable of providing bi-axial compressive or tensile loads with uni-axial motion and only one actuator. The specimen may be a cubic specimen including, without limitation, 3D printed cellular materials, composite materials, foams, bio-medical materials, and the like. The apparatus generally includes a first or top fixture forming a first re-entrant surface and a second or bottom fixture forming a second re-entrant surface. When the fixtures are mounted, the re-entrant surfaces form a testing space in the center to accommodate a specimen to be tested and the re-entrant surfaces provide testing forces in two axes in response to an actuator providing motion of at least one of the fixtures in one axis.

Abstract: An auxetic structure consistent with the present disclosure may include a core cell, capable of rotation, including a plurality of first rib sections, and a plurality of second rib sections. The first rib sections may be transverse to a longitudinal axis of the auxetic structure and at least one of the first rib sections may extend from the core cell. The second rib sections may be transverse to a transverse axis of the auxetic structure and at least one of the second rib sections may extend from the core cell.